Loading ...
Sorry, an error occurred while loading the content.
 

Power into Nuvi350 via FMI cable

Expand Messages
  • dondorgram
    Scott: You indicated you are looking at cloning the FMI interface. Just wonder if that includes being able to power the 350 via the interface rather than
    Message 1 of 23 , Mar 7, 2008
      Scott:

      You indicated you are looking at cloning the FMI interface. Just
      wonder if that includes being able to power the 350 via the
      interface rather than having to have power come in the mini USB on
      the back? Kind of a pain to have a second cable to mess around with.

      I took the heatshrink off one of my 10813 cables and noted that in
      addition to the black, white and yellow wires, there was a red and a
      green wire cut short. In a moment of optimism, I checked so see if
      they were connected through to the USB connector, but no luck.

      You said you opened up one of the interfaces. Are the green or red
      wires connected to anything? On the other side of the interface is
      there a wire to the +5V line on the mini USB? If so, is it
      worthwhile trying to crack open the molding and run a bypass? Do you
      have any pictures?

      Graham VE6GW
    • Scott Miller
      The 10813 cable has +5 volts from the USB connector on the red wire. My rep seemed to think you couldn t power the unit from there, but I haven t tried yet.
      Message 2 of 23 , Mar 7, 2008
        The 10813 cable has +5 volts from the USB connector on the red wire. My
        rep seemed to think you couldn't power the unit from there, but I
        haven't tried yet.

        Cracking open the lump in the cable is a serious pain in the #$^@#%.
        You're likely to remove at least a couple of components in the process.

        I just successfully tested a substitute converter circuit that consists
        of just a couple of 8.2k resistors and a few 1N4148 diodes. A 3.3 volt
        zener would take the place of all but one of the 1N4148s.

        I'll try pulling the external power and see if +5 to the converter
        circuit disappears, and if so, whether I can inject power on that side.

        Scott

        dondorgram wrote:
        >
        >
        > Scott:
        >
        > You indicated you are looking at cloning the FMI interface. Just
        > wonder if that includes being able to power the 350 via the
        > interface rather than having to have power come in the mini USB on
        > the back? Kind of a pain to have a second cable to mess around with.
        >
        > I took the heatshrink off one of my 10813 cables and noted that in
        > addition to the black, white and yellow wires, there was a red and a
        > green wire cut short. In a moment of optimism, I checked so see if
        > they were connected through to the USB connector, but no luck.
        >
        > You said you opened up one of the interfaces. Are the green or red
        > wires connected to anything? On the other side of the interface is
        > there a wire to the +5V line on the mini USB? If so, is it
        > worthwhile trying to crack open the molding and run a bypass? Do you
        > have any pictures?
        >
        > Graham VE6GW
        >
        >
      • Joe Krout
        The +5 volts feeding out of the Nuvi to the FMI interface would explain the Serial accessory requires external power message that you get when you plug in
        Message 3 of 23 , Mar 8, 2008
          The +5 volts feeding out of the Nuvi to the FMI interface would
          explain the "Serial accessory requires external power" message that
          you get when you plug in the FMI cable without the USB power cable.
          My best guess is that the Nuvi is using a lower voltage battery, and
          the USB 5 volts is reguated down for internal use. When I check the
          rear connector, there is 3.25 volts on two pins, and no 5 volt reading
          on it. Since you can power the GPS from the side USB port when NOT
          using the FMI cable, I would think that you could feed power to the
          FMI interface AND the Nuvi from the Tracker2. Just my 2 cents worth.
          Since I only have one cable, I don't have the nerve to crack it open.

          Joe
          W0PWJ

          On Fri, Mar 7, 2008 at 5:40 PM, dondorgram <walker.graham@...> wrote:
          >
          > Scott:
          >
          > You indicated you are looking at cloning the FMI interface. Just
          > wonder if that includes being able to power the 350 via the
          > interface rather than having to have power come in the mini USB on
          > the back? Kind of a pain to have a second cable to mess around with.
          >
          > I took the heatshrink off one of my 10813 cables and noted that in
          > addition to the black, white and yellow wires, there was a red and a
          > green wire cut short. In a moment of optimism, I checked so see if
          > they were connected through to the USB connector, but no luck.
          >
          > You said you opened up one of the interfaces. Are the green or red
          > wires connected to anything? On the other side of the interface is
          > there a wire to the +5V line on the mini USB? If so, is it
          > worthwhile trying to crack open the molding and run a bypass? Do you
          > have any pictures?
          >
          > Graham VE6GW
          >
          >
          >
          >
          >
          > Yahoo! Groups Links
          >
          >
          >
          >
        • Scott Miller
          Yeah, that s exactly what I m seeing. Power it through the side connector and it doesn t complain about serial accessory power, and it shows that it s on
          Message 4 of 23 , Mar 8, 2008
            Yeah, that's exactly what I'm seeing. Power it through the side
            connector and it doesn't complain about serial accessory power, and it
            shows that it's on external power.

            I've got a working substitute circuit, just need to choose the final
            components I'm going to use and redo my circuit layout, since I screwed
            up the first one. It should be small enough to fit into a standard DB9
            shell. Just need to find the dang USB cables.

            Scott

            Joe Krout wrote:
            >
            >
            > The +5 volts feeding out of the Nuvi to the FMI interface would
            > explain the "Serial accessory requires external power" message that
            > you get when you plug in the FMI cable without the USB power cable.
            > My best guess is that the Nuvi is using a lower voltage battery, and
            > the USB 5 volts is reguated down for internal use. When I check the
            > rear connector, there is 3.25 volts on two pins, and no 5 volt reading
            > on it. Since you can power the GPS from the side USB port when NOT
            > using the FMI cable, I would think that you could feed power to the
            > FMI interface AND the Nuvi from the Tracker2. Just my 2 cents worth.
            > Since I only have one cable, I don't have the nerve to crack it open.
            >
            > Joe
            > W0PWJ
            >
            > On Fri, Mar 7, 2008 at 5:40 PM, dondorgram <walker.graham@...
            > <mailto:walker.graham%40ic.gc.ca>> wrote:
            > >
            > > Scott:
            > >
            > > You indicated you are looking at cloning the FMI interface. Just
            > > wonder if that includes being able to power the 350 via the
            > > interface rather than having to have power come in the mini USB on
            > > the back? Kind of a pain to have a second cable to mess around with.
            > >
            > > I took the heatshrink off one of my 10813 cables and noted that in
            > > addition to the black, white and yellow wires, there was a red and a
            > > green wire cut short. In a moment of optimism, I checked so see if
            > > they were connected through to the USB connector, but no luck.
            > >
            > > You said you opened up one of the interfaces. Are the green or red
            > > wires connected to anything? On the other side of the interface is
            > > there a wire to the +5V line on the mini USB? If so, is it
            > > worthwhile trying to crack open the molding and run a bypass? Do you
            > > have any pictures?
            > >
            > > Graham VE6GW
            > >
            > >
            > >
            > >
            > >
            > > Yahoo! Groups Links
            > >
            > >
            > >
            > >
            >
            >
          • Joe Krout
            Have you determined what the extra wire is? The attached links talk about an ID Pin that is grounded making the mini-b, a mini-a connector. This is done to
            Message 5 of 23 , Mar 8, 2008
              Have you determined what the extra wire is?
              The attached links talk about an ID Pin that is grounded making the
              mini-b, a mini-a connector. This is done to implement the "USB on the
              go" standard that allows to devices to communicate without a "host" PC.
              My guess is that the Nuvi is at the "A" end and the interface is the B
              end. I think you mentioned a resistor in the cable somewhere? Did it
              go to ground?
              "http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/"
              "http://www.hardwarebook.info/Universal_Serial_Bus_(USB)"


              Thanks again,
              Joe
              W0PWJ




              -----Original Message-----
              From: tracker2@yahoogroups.com [mailto:tracker2@yahoogroups.com] On
              Behalf Of Scott Miller
              Sent: Saturday, March 08, 2008 4:17 PM
              To: tracker2@yahoogroups.com
              Subject: Re: [tracker2] Power into Nuvi350 via FMI cable

              <snip>...

              I've got a working substitute circuit, just need to choose the final
              components I'm going to use and redo my circuit layout, since I screwed
              up the first one. It should be small enough to fit into a standard DB9
              shell. Just need to find the dang USB cables.

              Scott


              ...<whack>
            • Scott Miller
              Which extra wire? The extra contact on the 5-pin mini-B connector is an 8.2k resistor to ground that it uses to sense the serial accessory cable. Not the
              Message 6 of 23 , Mar 8, 2008
                Which extra wire?

                The extra contact on the 5-pin mini-B connector is an 8.2k resistor to
                ground that it uses to sense the serial accessory cable. Not the
                standard OTG arrangement, apparently.

                Aside from that, it's just +5v, GND, D-, and D+.

                Scott

                Joe Krout wrote:
                >
                >
                > Have you determined what the extra wire is?
                > The attached links talk about an ID Pin that is grounded making the
                > mini-b, a mini-a connector. This is done to implement the "USB on the
                > go" standard that allows to devices to communicate without a "host" PC.
                > My guess is that the Nuvi is at the "A" end and the interface is the B
                > end. I think you mentioned a resistor in the cable somewhere? Did it
                > go to ground?
                > "http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/
                > <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/>"
                > "http://www.hardwarebook.info/Universal_Serial_Bus_
                > <http://www.hardwarebook.info/Universal_Serial_Bus_>(USB)"
                >
                > Thanks again,
                > Joe
                > W0PWJ
                >
                > -----Original Message-----
                > From: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                > [mailto:tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>] On
                > Behalf Of Scott Miller
                > Sent: Saturday, March 08, 2008 4:17 PM
                > To: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                > Subject: Re: [tracker2] Power into Nuvi350 via FMI cable
                >
                > <snip>...
                >
                > I've got a working substitute circuit, just need to choose the final
                > components I'm going to use and redo my circuit layout, since I screwed
                > up the first one. It should be small enough to fit into a standard DB9
                > shell. Just need to find the dang USB cables.
                >
                > Scott
                >
                > ...<whack>
                >
                >
              • Joe Krout
                ... From your post on 2/14/08 I thought there were 5 wires in the cable. ... I think the resistor is what is making the connector a mini-A, instead of a
                Message 7 of 23 , Mar 9, 2008
                  > -----Original Message-----
                  > From: tracker2@yahoogroups.com
                  > [mailto:tracker2@yahoogroups.com] On Behalf Of Scott Miller
                  > Sent: Saturday, March 08, 2008 7:36 PM
                  > To: tracker2@yahoogroups.com
                  > Subject: Re: [tracker2] Power into Nuvi350 via FMI cable
                  >
                  >
                  > Which extra wire?

                  From your post on 2/14/08 I thought there were 5 wires in the cable.

                  >>I did tear apart an 813 cable and documented the circuit. Turns out
                  >>there's also a resistor that's separate from the circuit in the
                  >>mid-cable lump. I think I can duplicate and simplify the circuit, but

                  >>the hard part might be finding 5-conductor USB mini-B cables. For
                  >>larger quantities, I can get them custom-made, but I'm not doing that
                  >>quite yet.

                  >
                  > The extra contact on the 5-pin mini-B connector is an 8.2k
                  > resistor to
                  > ground that it uses to sense the serial accessory cable. Not the
                  > standard OTG arrangement, apparently.
                  >
                  > Aside from that, it's just +5v, GND, D-, and D+.
                  >

                  I think the resistor is what is making the connector a mini-A, instead
                  of a mini-B.
                  That sounds like the ID pin described in the Maxim app notes.
                  http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/

                  Here is a better description of the Mini-B/Mini-A
                  http://www.edn.com/article/CA181883.html

                  The Garmin 12volt power cable and the FMI cable look like they have the
                  same usb plug on them. Do yo think Garmin used one cable style and
                  added an external resistor to enable the ID pin on the FMI cable? Or is
                  the resistor part of the connector?

                  I found one source of Mini-A plugs that might be useful to you
                  http://www.acon.com/wps/wcm/connect/en/connector/miniusb1.htm#

                  Keep up the good work Scott, The Tracker2 is Great!

                  Joe
                  W0PWJ



                  > Scott
                  >
                  > Joe Krout wrote:
                  > >
                  > >
                  > > Have you determined what the extra wire is?
                  > > The attached links talk about an ID Pin that is grounded making the
                  > > mini-b, a mini-a connector. This is done to implement the
                  > "USB on the
                  > > go" standard that allows to devices to communicate without a "host"
                  > > PC. My guess is that the Nuvi is at the "A" end and the
                  > interface is
                  > > the B end. I think you mentioned a resistor in the cable somewhere?
                  > > Did it go to ground?
                  > > "http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/
                  > > <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/>"
                  > > "http://www.hardwarebook.info/Universal_Serial_Bus_
                  > > <http://www.hardwarebook.info/Universal_Serial_Bus_>(USB)"
                  > >
                  > > Thanks again,
                  > > Joe
                  > > W0PWJ
                  > >
                  > > -----Original Message-----
                  > > From: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                  > > [mailto:tracker2@yahoogroups.com
                  > <mailto:tracker2%40yahoogroups.com>] On
                  > > Behalf Of Scott
                  > Miller
                  > > Sent: Saturday, March 08, 2008 4:17 PM
                  > > To: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                  > > Subject: Re: [tracker2] Power into Nuvi350 via FMI cable
                  > >
                  > > <snip>...
                  > >
                  > > I've got a working substitute circuit, just need to choose
                  > the final
                  > > components I'm going to use and redo my circuit layout, since I
                  > > screwed up the first one. It should be small enough to fit into a
                  > > standard DB9 shell. Just need to find the dang USB cables.
                  > >
                  > > Scott
                  > >
                  > > ...<whack>
                  > >
                  > >
                  >
                  >
                  >
                  >
                  > Yahoo! Groups Links
                  >
                  >
                  >
                  >
                • Scott Miller
                  ... The resistor is part of the connector. Scott
                  Message 8 of 23 , Mar 9, 2008
                    > added an external resistor to enable the ID pin on the FMI cable? Or is
                    > the resistor part of the connector?

                    The resistor is part of the connector.

                    Scott
                  • gervais fillion
                    Scott, i wonder if this cable could be used between the OT2 and an FD-150A Portable????
                    Message 9 of 23 , Mar 10, 2008

                      Scott,
                      i wonder if this cable could be used between the OT2 and an FD-150A Portable????
                      http://cgi.cafr.ebay.ca/Program-cable-for-FDC-FD-150A-FD-160A-FD-450A-FD-460A_W0QQitemZ140200706171QQihZ004QQcategoryZ48704QQcmdZViewItem
                       
                       
                       
                       
                      73/s
                      Gervais,ve2ckn

                      > To: tracker2@yahoogroups.com>
                      From: scott@...
                      > Date: Sun, 9 Mar 2008 11:02:38 -0700
                      > Subject: Re: [tracker2] Power into Nuvi350 via FMI cable
                      >
                      > > added an external resistor to enable the ID pin on the FMI cable? Or is
                      > > the resistor part of the connector?
                      >
                      > The resistor is part of the connector.
                      >
                      > Scott
                      >
                      >
                      >
                      >
                      > Yahoo! Groups Links
                      >
                      > <*> To visit your group on the web, go to:
                      > http://groups.yahoo.com/group/tracker2/
                      >
                      > <*> Your email settings:
                      > Individual Email | Traditional
                      >
                      > <*> To change settings online go to:
                      > http://groups.yahoo.com/group/tracker2/join
                      > (Yahoo! ID required)
                      >
                      > <*> To change settings via email:
                      > mailto:tracker2-digest@yahoogroups.com
                      > mailto:tracker2-fullfeatured@yahoogroups.com
                      >
                      > <*> To unsubscribe from this group, send an email to:
                      > tracker2-unsubscribe@yahoogroups.com
                      >
                      > <*> Your use of Yahoo! Groups is subject to:
                      > http://docs.yahoo.com/info/terms/
                      >



                      Trouvez vos infos rapidement et précisément avec Windows Live Instant Search ! Essayez-le maintenant!
                    • Scott Miller
                      No, that s only for programming. You can get pre-built cables from www.rpc-electronics.com. I think the FD-150 takes the Kenwood style connector, like almost
                      Message 10 of 23 , Mar 11, 2008
                        No, that's only for programming. You can get pre-built cables from
                        www.rpc-electronics.com. I think the FD-150 takes the Kenwood style
                        connector, like almost all of the Chinese brands.

                        Scott

                        gervais fillion wrote:
                        >
                        >
                        >
                        > Scott,
                        > i wonder if this cable could be used between the OT2 and an FD-150A
                        > Portable????
                        > http://cgi.cafr.ebay.ca/Program-cable-for-FDC-FD-150A-FD-160A-FD-450A-FD-460A_W0QQitemZ140200706171QQihZ004QQcategoryZ48704QQcmdZViewItem
                        > <http://cgi.cafr.ebay.ca/Program-cable-for-FDC-FD-150A-FD-160A-FD-450A-FD-460A_W0QQitemZ140200706171QQihZ004QQcategoryZ48704QQcmdZViewItem>
                        >
                        >
                        >
                        >
                        > 73/s
                        > Gervais,ve2ckn
                        >
                        > > To: tracker2@yahoogroups.com>
                        > From: scott@...
                        > > Date: Sun, 9 Mar 2008 11:02:38 -0700
                        > > Subject: Re: [tracker2] Power into Nuvi350 via FMI cable
                        > >
                        > > > added an external resistor to enable the ID pin on the FMI cable? Or is
                        > > > the resistor part of the connector?
                        > >
                        > > The resistor is part of the connector.
                        > >
                        > > Scott
                        > >
                        > >
                        > >
                        > >
                        > > Yahoo! Groups Links
                        > >
                        > >
                        > >
                        >
                        >
                        > ------------------------------------------------------------------------
                        > Trouvez vos infos rapidement et précisément avec Windows Live Instant
                        > Search ! Essayez-le maintenant! <http://g.msn.ca/ca55/220>
                        >
                      • Joe Krout
                        Well, I couldn t take it any longer. I now have a FMI cable that supplies power to the NUVI from the OT2m! I am working on a Go box for the NUVI and the OTM2
                        Message 11 of 23 , Mar 16, 2008
                          Well, I couldn't take it any longer.
                          I now have a FMI cable that supplies power to the NUVI from the OT2m!
                          I am working on a Go box for the NUVI and the OTM2 with a

                          This is what I did.

                          The information provided is for educational purposes only.
                          I am NOT a trained professional. I did try this at home.
                          No, I did not take any pictures, I already know what I look like.
                          Should you choose to attempt this proceed at your own risk.
                          I will not take any responsibility for your actions.

                          I carefully sliced open the insulation and shielding on the FMI cable
                          about 2 inches from each side of the Garmin "bump" and fished out the
                          red wire. I made about a 1 inch long slice axially.
                          On the USB side, I soldered a wire in to the red wire, without cutting
                          the existing wire.
                          On the serial side of the "bump" I fished out the red wire, cut it in
                          two and soldered the other end of the spliced wire to the serial side of
                          the cut red wire.
                          At the serial connector, I verified that I had +5 volts on pin 4 and
                          connected the red wire into it.
                          The black ground wire already passes through the "bump" to the USB
                          connector, (ignore the green wire.)
                          I coated the slices in the cable with liquid plastic and taped over
                          everything.

                          It works for me. Your results may vary.

                          73
                          Joe W0PWJ



                          > -----Original Message-----
                          > From: tracker2@yahoogroups.com
                          > [mailto:tracker2@yahoogroups.com] On Behalf Of Scott Miller
                          > Sent: Saturday, March 08, 2008 7:36 PM
                          > To: tracker2@yahoogroups.com
                          > Subject: Re: [tracker2] Power into Nuvi350 via FMI cable
                          >
                          >
                          > Which extra wire?
                          >
                          > The extra contact on the 5-pin mini-B connector is an 8.2k
                          > resistor to
                          > ground that it uses to sense the serial accessory cable. Not the
                          > standard OTG arrangement, apparently.
                          >
                          > Aside from that, it's just +5v, GND, D-, and D+.
                          >
                          > Scott
                          >
                          > Joe Krout wrote:
                          > >
                          > >
                          > > Have you determined what the extra wire is?
                          > > The attached links talk about an ID Pin that is grounded making the
                          > > mini-b, a mini-a connector. This is done to implement the
                          > "USB on the
                          > > go" standard that allows to devices to communicate without a "host"
                          > > PC. My guess is that the Nuvi is at the "A" end and the
                          > interface is
                          > > the B end. I think you mentioned a resistor in the cable somewhere?
                          > > Did it go to ground?
                          > > "http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/
                          > > <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/>"
                          > > "http://www.hardwarebook.info/Universal_Serial_Bus_
                          > > <http://www.hardwarebook.info/Universal_Serial_Bus_>(USB)"
                          > >
                          > > Thanks again,
                          > > Joe
                          > > W0PWJ
                          > >
                          > > -----Original Message-----
                          > > From: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                          > > [mailto:tracker2@yahoogroups.com
                          > <mailto:tracker2%40yahoogroups.com>] On
                          > > Behalf Of Scott
                          > Miller
                          > > Sent: Saturday, March 08, 2008 4:17 PM
                          > > To: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                          > > Subject: Re: [tracker2] Power into Nuvi350 via FMI cable
                          > >
                          > > <snip>...
                          > >
                          > > I've got a working substitute circuit, just need to choose
                          > the final
                          > > components I'm going to use and redo my circuit layout, since I
                          > > screwed up the first one. It should be small enough to fit into a
                          > > standard DB9 shell. Just need to find the dang USB cables.
                          > >
                          > > Scott
                          > >
                          > > ...<whack>
                          > >
                          > >
                          >
                          >
                          >
                          >
                          > Yahoo! Groups Links
                          >
                          >
                          >
                          >
                        • Joe Krout
                          Scott, Do you foresee any problem if I replace the 78m05 with a 7805 regualtor? I remember you mentioning that the current draw to the NUVI through a modifed
                          Message 12 of 23 , Mar 16, 2008
                            Scott,
                            Do you foresee any problem if I replace the 78m05 with a 7805 regualtor?
                            I remember you mentioning that the current draw to the NUVI through a
                            modifed FMI cable was close to the limit for the 78m05 at 12 volts.
                            Thought maybe a change to a 1 amp regulator would reduce heating.

                            Thanks
                            Joe W0PWJ
                          • Scott Miller
                            Electrically there s no problem with it. I m not sure how well it ll mate to the board for heat dissipation, though. Scott
                            Message 13 of 23 , Mar 16, 2008
                              Electrically there's no problem with it. I'm not sure how well it'll
                              mate to the board for heat dissipation, though.

                              Scott

                              Joe Krout wrote:
                              >
                              >
                              > Scott,
                              > Do you foresee any problem if I replace the 78m05 with a 7805 regualtor?
                              > I remember you mentioning that the current draw to the NUVI through a
                              > modifed FMI cable was close to the limit for the 78m05 at 12 volts.
                              > Thought maybe a change to a 1 amp regulator would reduce heating.
                              >
                              > Thanks
                              > Joe W0PWJ
                              >
                              >
                            • Joe Krout
                              I haven t worked out the specifics, but I was thinking about extending the leads and heat sinking it to the case, or using a small heatsink from an old PC
                              Message 14 of 23 , Mar 16, 2008
                                I haven't worked out the specifics, but I was thinking about extending
                                the leads and heat sinking it to the case, or using a small heatsink
                                from an old PC video chip. I will see what I can come up with.

                                Joe

                                > -----Original Message-----
                                > From: tracker2@yahoogroups.com
                                > [mailto:tracker2@yahoogroups.com] On Behalf Of Scott Miller
                                > Sent: Sunday, March 16, 2008 8:01 PM
                                > To: tracker2@yahoogroups.com
                                > Subject: Re: [tracker2] Power into Nuvi350 via FMI cable
                                >
                                >
                                > Electrically there's no problem with it. I'm not sure how well it'll
                                > mate to the board for heat dissipation, though.
                                >
                                > Scott
                                >
                                > Joe Krout wrote:
                                > >
                                > >
                                > > Scott,
                                > > Do you foresee any problem if I replace the 78m05 with a 7805
                                > > regualtor? I remember you mentioning that the current draw
                                > to the NUVI
                                > > through a modifed FMI cable was close to the limit for the
                                > 78m05 at 12
                                > > volts. Thought maybe a change to a 1 amp regulator would reduce
                                > > heating.
                                > >
                                > > Thanks
                                > > Joe W0PWJ
                                > >
                                > >
                                >
                                >
                                > ------------------------------------
                                >
                                > Yahoo! Groups Links
                                >
                                >
                                >
                              • P. Suryono Adisoemarta
                                I was thinking that you can skip slicing the red wire at the mini-USB side, and just sliced the red wire at the DB9 to hook to Pin 4 on the serial port. de
                                Message 15 of 23 , Mar 16, 2008
                                  I was thinking that you can skip slicing the red wire
                                  at the mini-USB side, and just sliced the red wire at
                                  the DB9 to hook to Pin 4 on the serial port.

                                  de N5SNN



                                  --- Joe Krout <jkrout@...> wrote:

                                  > Well, I couldn't take it any longer.
                                  > I now have a FMI cable that supplies power to the
                                  > NUVI from the OT2m!
                                  > I am working on a Go box for the NUVI and the OTM2
                                  > with a
                                  >
                                  > This is what I did.
                                  >
                                  > The information provided is for educational purposes
                                  > only.
                                  > I am NOT a trained professional. I did try this at
                                  > home.
                                  > No, I did not take any pictures, I already know what
                                  > I look like.
                                  > Should you choose to attempt this proceed at your
                                  > own risk.
                                  > I will not take any responsibility for your actions.
                                  >
                                  >
                                  > I carefully sliced open the insulation and shielding
                                  > on the FMI cable
                                  > about 2 inches from each side of the Garmin "bump"
                                  > and fished out the
                                  > red wire. I made about a 1 inch long slice axially.
                                  > On the USB side, I soldered a wire in to the red
                                  > wire, without cutting
                                  > the existing wire.
                                  > On the serial side of the "bump" I fished out the
                                  > red wire, cut it in
                                  > two and soldered the other end of the spliced wire
                                  > to the serial side of
                                  > the cut red wire.
                                  > At the serial connector, I verified that I had +5
                                  > volts on pin 4 and
                                  > connected the red wire into it.
                                  > The black ground wire already passes through the
                                  > "bump" to the USB
                                  > connector, (ignore the green wire.)
                                  > I coated the slices in the cable with liquid plastic
                                  > and taped over
                                  > everything.
                                  >
                                  > It works for me. Your results may vary.
                                  >
                                  > 73
                                  > Joe W0PWJ
                                  >
                                  >
                                  >
                                  > > -----Original Message-----
                                  > > From: tracker2@yahoogroups.com
                                  > > [mailto:tracker2@yahoogroups.com] On Behalf Of
                                  > Scott Miller
                                  > > Sent: Saturday, March 08, 2008 7:36 PM
                                  > > To: tracker2@yahoogroups.com
                                  > > Subject: Re: [tracker2] Power into Nuvi350 via FMI
                                  > cable
                                  > >
                                  > >
                                  > > Which extra wire?
                                  > >
                                  > > The extra contact on the 5-pin mini-B connector is
                                  > an 8.2k
                                  > > resistor to
                                  > > ground that it uses to sense the serial accessory
                                  > cable. Not the
                                  > > standard OTG arrangement, apparently.
                                  > >
                                  > > Aside from that, it's just +5v, GND, D-, and D+.
                                  > >
                                  > > Scott
                                  > >
                                  > > Joe Krout wrote:
                                  > > >
                                  > > >
                                  > > > Have you determined what the extra wire is?
                                  > > > The attached links talk about an ID Pin that is
                                  > grounded making the
                                  > > > mini-b, a mini-a connector. This is done to
                                  > implement the
                                  > > "USB on the
                                  > > > go" standard that allows to devices to
                                  > communicate without a "host"
                                  > > > PC. My guess is that the Nuvi is at the "A" end
                                  > and the
                                  > > interface is
                                  > > > the B end. I think you mentioned a resistor in
                                  > the cable somewhere?
                                  > > > Did it go to ground?
                                  > > >
                                  >
                                  "http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/
                                  > > >
                                  >
                                  <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/>"
                                  > > >
                                  > "http://www.hardwarebook.info/Universal_Serial_Bus_
                                  > > >
                                  >
                                  <http://www.hardwarebook.info/Universal_Serial_Bus_>(USB)"
                                  > > >
                                  > > > Thanks again,
                                  > > > Joe
                                  > > > W0PWJ
                                  > > >
                                  > > > -----Original Message-----
                                  > > > From: tracker2@yahoogroups.com
                                  > <mailto:tracker2%40yahoogroups.com>
                                  > > > [mailto:tracker2@yahoogroups.com
                                  > > <mailto:tracker2%40yahoogroups.com>] On
                                  > > > Behalf Of Scott
                                  > > Miller
                                  > > > Sent: Saturday, March 08, 2008 4:17 PM
                                  > > > To: tracker2@yahoogroups.com
                                  > <mailto:tracker2%40yahoogroups.com>
                                  > > > Subject: Re: [tracker2] Power into Nuvi350 via
                                  > FMI cable
                                  > > >
                                  > > > <snip>...
                                  > > >
                                  > > > I've got a working substitute circuit, just need
                                  > to choose
                                  > > the final
                                  > > > components I'm going to use and redo my circuit
                                  > layout, since I
                                  > > > screwed up the first one. It should be small
                                  > enough to fit into a
                                  > > > standard DB9 shell. Just need to find the dang
                                  > USB cables.
                                  > > >
                                  > > > Scott
                                  > > >
                                  > > > ...<whack>
                                  > > >
                                  > > >
                                  > >
                                  > >
                                  > >
                                  > >
                                  > > Yahoo! Groups Links
                                  > >
                                  > >
                                  > >
                                  > >
                                  >
                                  >
                                  > ------------------------------------
                                  >
                                  > Yahoo! Groups Links
                                  >
                                  >
                                  >
                                  >
                                  >



                                  ____________________________________________________________________________________
                                  Never miss a thing. Make Yahoo your home page.
                                  http://www.yahoo.com/r/hs
                                • Joe Krout
                                  I checked that possibility with an ohm meter. The red wire does not pass through the Garmin bump in the cable. Not sure if it is tied to anything in the
                                  Message 16 of 23 , Mar 16, 2008
                                    I checked that possibility with an ohm meter. The red wire does not
                                    pass through the Garmin "bump" in the cable. Not sure if it is tied to
                                    anything in the bump, that is why I cut it on the serial side and
                                    insulated the stub going into the bump. By teeing it on the USB side, I
                                    am sending 5 volts to the bump and to the Nuvi.
                                    Probably worth mentioning that the power cord to the back of the NUVI
                                    should not be used with the modified FMI cable. Also, the FMI cable
                                    (modified or not) must be plugged into the side USB port. My primary
                                    reason for making the mod was to eliminate the cigarette lighter plug
                                    and the second cable. Makes wiring my Go Box much easier.

                                    Joe
                                    W0PWJ

                                    > -----Original Message-----
                                    > From: tracker2@yahoogroups.com
                                    > [mailto:tracker2@yahoogroups.com] On Behalf Of P. Suryono Adisoemarta
                                    > Sent: Sunday, March 16, 2008 9:10 PM
                                    > To: tracker2@yahoogroups.com
                                    > Subject: RE: [tracker2] Power into Nuvi350 via FMI cable
                                    >
                                    >
                                    >
                                    > I was thinking that you can skip slicing the red wire
                                    > at the mini-USB side, and just sliced the red wire at
                                    > the DB9 to hook to Pin 4 on the serial port.
                                    >
                                    > de N5SNN
                                    >
                                    >
                                    >
                                    > --- Joe Krout <jkrout@...> wrote:
                                    >
                                    > > Well, I couldn't take it any longer.
                                    > > I now have a FMI cable that supplies power to the
                                    > > NUVI from the OT2m!
                                    > > I am working on a Go box for the NUVI and the OTM2
                                    > > with a
                                    > >
                                    > > This is what I did.
                                    > >
                                    > > The information provided is for educational purposes
                                    > > only.
                                    > > I am NOT a trained professional. I did try this at
                                    > > home.
                                    > > No, I did not take any pictures, I already know what
                                    > > I look like.
                                    > > Should you choose to attempt this proceed at your
                                    > > own risk.
                                    > > I will not take any responsibility for your actions.
                                    > >
                                    > >
                                    > > I carefully sliced open the insulation and shielding
                                    > > on the FMI cable
                                    > > about 2 inches from each side of the Garmin "bump"
                                    > > and fished out the
                                    > > red wire. I made about a 1 inch long slice axially.
                                    > > On the USB side, I soldered a wire in to the red
                                    > > wire, without cutting
                                    > > the existing wire.
                                    > > On the serial side of the "bump" I fished out the
                                    > > red wire, cut it in
                                    > > two and soldered the other end of the spliced wire
                                    > > to the serial side of
                                    > > the cut red wire.
                                    > > At the serial connector, I verified that I had +5
                                    > > volts on pin 4 and
                                    > > connected the red wire into it.
                                    > > The black ground wire already passes through the
                                    > > "bump" to the USB
                                    > > connector, (ignore the green wire.)
                                    > > I coated the slices in the cable with liquid plastic
                                    > > and taped over
                                    > > everything.
                                    > >
                                    > > It works for me. Your results may vary.
                                    > >
                                    > > 73
                                    > > Joe W0PWJ
                                    > >
                                    > >
                                    > >
                                    > > > -----Original Message-----
                                    > > > From: tracker2@yahoogroups.com
                                    > > > [mailto:tracker2@yahoogroups.com] On Behalf Of
                                    > > Scott Miller
                                    > > > Sent: Saturday, March 08, 2008 7:36 PM
                                    > > > To: tracker2@yahoogroups.com
                                    > > > Subject: Re: [tracker2] Power into Nuvi350 via FMI
                                    > > cable
                                    > > >
                                    > > >
                                    > > > Which extra wire?
                                    > > >
                                    > > > The extra contact on the 5-pin mini-B connector is
                                    > > an 8.2k
                                    > > > resistor to
                                    > > > ground that it uses to sense the serial accessory
                                    > > cable. Not the
                                    > > > standard OTG arrangement, apparently.
                                    > > >
                                    > > > Aside from that, it's just +5v, GND, D-, and D+.
                                    > > >
                                    > > > Scott
                                    > > >
                                    > > > Joe Krout wrote:
                                    > > > >
                                    > > > >
                                    > > > > Have you determined what the extra wire is?
                                    > > > > The attached links talk about an ID Pin that is
                                    > > grounded making the
                                    > > > > mini-b, a mini-a connector. This is done to
                                    > > implement the
                                    > > > "USB on the
                                    > > > > go" standard that allows to devices to
                                    > > communicate without a "host"
                                    > > > > PC. My guess is that the Nuvi is at the "A" end
                                    > > and the
                                    > > > interface is
                                    > > > > the B end. I think you mentioned a resistor in
                                    > > the cable somewhere?
                                    > > > > Did it go to ground?
                                    > > > >
                                    > >
                                    > "http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/
                                    > > > >
                                    > >
                                    > <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/>"
                                    > > > >
                                    > > "http://www.hardwarebook.info/Universal_Serial_Bus_
                                    > > > >
                                    > >
                                    > <http://www.hardwarebook.info/Universal_Serial_Bus_>(USB)"
                                    > > > >
                                    > > > > Thanks again,
                                    > > > > Joe
                                    > > > > W0PWJ
                                    > > > >
                                    > > > > -----Original Message-----
                                    > > > > From: tracker2@yahoogroups.com
                                    > > <mailto:tracker2%40yahoogroups.com>
                                    > > > > [mailto:tracker2@yahoogroups.com
                                    > > > <mailto:tracker2%40yahoogroups.com>] On
                                    > > > > Behalf Of Scott
                                    > > > Miller
                                    > > > > Sent: Saturday, March 08, 2008 4:17 PM
                                    > > > > To: tracker2@yahoogroups.com
                                    > > <mailto:tracker2%40yahoogroups.com>
                                    > > > > Subject: Re: [tracker2] Power into Nuvi350 via
                                    > > FMI cable
                                    > > > >
                                    > > > > <snip>...
                                    > > > >
                                    > > > > I've got a working substitute circuit, just need
                                    > > to choose
                                    > > > the final
                                    > > > > components I'm going to use and redo my circuit
                                    > > layout, since I
                                    > > > > screwed up the first one. It should be small
                                    > > enough to fit into a
                                    > > > > standard DB9 shell. Just need to find the dang
                                    > > USB cables.
                                    > > > >
                                    > > > > Scott
                                    > > > >
                                    > > > > ...<whack>
                                    > > > >
                                    > > > >
                                    > > >
                                    > > >
                                    > > >
                                    > > >
                                    > > > Yahoo! Groups Links
                                    > > >
                                    > > >
                                    > > >
                                    > > >
                                    > >
                                    > >
                                    > > ------------------------------------
                                    > >
                                    > > Yahoo! Groups Links
                                    > >
                                    > >
                                    > >
                                    > >
                                    > >
                                    >
                                    >
                                    >
                                    >
                                    > ______________________________________________________________
                                    > ______________________
                                    > Never miss a thing. Make Yahoo your home page.
                                    > http://www.yahoo.com/r/hs
                                    >
                                    > ------------------------------------
                                    >
                                    > Yahoo! Groups Links
                                    >
                                    >
                                    >
                                  • Scott Miller
                                    The red wire coming from the USB side powers the converter circuit, but it doesn t go anywhere else. All you really need is a 5-conductor USB cable (good
                                    Message 17 of 23 , Mar 16, 2008
                                      The red wire coming from the USB side powers the converter circuit, but
                                      it doesn't go anywhere else.

                                      All you really need is a 5-conductor USB cable (good luck), a couple of
                                      8.2k resistors, and a couple of diodes. The data in (from GPS to T2)
                                      doesn't need anything done to it at all. The data out needs to be
                                      limited to 0-3.3 volts. I did that with a series diode and a string of
                                      diodes to ground since I didn't have a zener in the 3.3 volt range. One
                                      resistor goes between the extra USB pin (the one that doesn't have a
                                      number in the USB spec) and ground. The other resistor goes between the
                                      T2 and the diodes to limit the current.

                                      Scott

                                      Joe Krout wrote:
                                      >
                                      >
                                      > I checked that possibility with an ohm meter. The red wire does not
                                      > pass through the Garmin "bump" in the cable. Not sure if it is tied to
                                      > anything in the bump, that is why I cut it on the serial side and
                                      > insulated the stub going into the bump. By teeing it on the USB side, I
                                      > am sending 5 volts to the bump and to the Nuvi.
                                      > Probably worth mentioning that the power cord to the back of the NUVI
                                      > should not be used with the modified FMI cable. Also, the FMI cable
                                      > (modified or not) must be plugged into the side USB port. My primary
                                      > reason for making the mod was to eliminate the cigarette lighter plug
                                      > and the second cable. Makes wiring my Go Box much easier.
                                      >
                                      > Joe
                                      > W0PWJ
                                      >
                                      > > -----Original Message-----
                                      > > From: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                                      > > [mailto:tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>]
                                      > On Behalf Of P. Suryono Adisoemarta
                                      > > Sent: Sunday, March 16, 2008 9:10 PM
                                      > > To: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                                      > > Subject: RE: [tracker2] Power into Nuvi350 via FMI cable
                                      > >
                                      > >
                                      > >
                                      > > I was thinking that you can skip slicing the red wire
                                      > > at the mini-USB side, and just sliced the red wire at
                                      > > the DB9 to hook to Pin 4 on the serial port.
                                      > >
                                      > > de N5SNN
                                      > >
                                      > >
                                      > >
                                      > > --- Joe Krout <jkrout@... <mailto:jkrout%40gmail.com>> wrote:
                                      > >
                                      > > > Well, I couldn't take it any longer.
                                      > > > I now have a FMI cable that supplies power to the
                                      > > > NUVI from the OT2m!
                                      > > > I am working on a Go box for the NUVI and the OTM2
                                      > > > with a
                                      > > >
                                      > > > This is what I did.
                                      > > >
                                      > > > The information provided is for educational purposes
                                      > > > only.
                                      > > > I am NOT a trained professional. I did try this at
                                      > > > home.
                                      > > > No, I did not take any pictures, I already know what
                                      > > > I look like.
                                      > > > Should you choose to attempt this proceed at your
                                      > > > own risk.
                                      > > > I will not take any responsibility for your actions.
                                      > > >
                                      > > >
                                      > > > I carefully sliced open the insulation and shielding
                                      > > > on the FMI cable
                                      > > > about 2 inches from each side of the Garmin "bump"
                                      > > > and fished out the
                                      > > > red wire. I made about a 1 inch long slice axially.
                                      > > > On the USB side, I soldered a wire in to the red
                                      > > > wire, without cutting
                                      > > > the existing wire.
                                      > > > On the serial side of the "bump" I fished out the
                                      > > > red wire, cut it in
                                      > > > two and soldered the other end of the spliced wire
                                      > > > to the serial side of
                                      > > > the cut red wire.
                                      > > > At the serial connector, I verified that I had +5
                                      > > > volts on pin 4 and
                                      > > > connected the red wire into it.
                                      > > > The black ground wire already passes through the
                                      > > > "bump" to the USB
                                      > > > connector, (ignore the green wire.)
                                      > > > I coated the slices in the cable with liquid plastic
                                      > > > and taped over
                                      > > > everything.
                                      > > >
                                      > > > It works for me. Your results may vary.
                                      > > >
                                      > > > 73
                                      > > > Joe W0PWJ
                                      > > >
                                      > > >
                                      > > >
                                      > > > > -----Original Message-----
                                      > > > > From: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                                      > > > > [mailto:tracker2@yahoogroups.com
                                      > <mailto:tracker2%40yahoogroups.com>] On Behalf Of
                                      > > > Scott Miller
                                      > > > > Sent: Saturday, March 08, 2008 7:36 PM
                                      > > > > To: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                                      > > > > Subject: Re: [tracker2] Power into Nuvi350 via FMI
                                      > > > cable
                                      > > > >
                                      > > > >
                                      > > > > Which extra wire?
                                      > > > >
                                      > > > > The extra contact on the 5-pin mini-B connector is
                                      > > > an 8.2k
                                      > > > > resistor to
                                      > > > > ground that it uses to sense the serial accessory
                                      > > > cable. Not the
                                      > > > > standard OTG arrangement, apparently.
                                      > > > >
                                      > > > > Aside from that, it's just +5v, GND, D-, and D+.
                                      > > > >
                                      > > > > Scott
                                      > > > >
                                      > > > > Joe Krout wrote:
                                      > > > > >
                                      > > > > >
                                      > > > > > Have you determined what the extra wire is?
                                      > > > > > The attached links talk about an ID Pin that is
                                      > > > grounded making the
                                      > > > > > mini-b, a mini-a connector. This is done to
                                      > > > implement the
                                      > > > > "USB on the
                                      > > > > > go" standard that allows to devices to
                                      > > > communicate without a "host"
                                      > > > > > PC. My guess is that the Nuvi is at the "A" end
                                      > > > and the
                                      > > > > interface is
                                      > > > > > the B end. I think you mentioned a resistor in
                                      > > > the cable somewhere?
                                      > > > > > Did it go to ground?
                                      > > > > >
                                      > > >
                                      > > "http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/
                                      > <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/>
                                      > > > > >
                                      > > >
                                      > > <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/
                                      > <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/>>"
                                      > > > > >
                                      > > > "http://www.hardwarebook.info/Universal_Serial_Bus_
                                      > <http://www.hardwarebook.info/Universal_Serial_Bus_>
                                      > > > > >
                                      > > >
                                      > > <http://www.hardwarebook.info/Universal_Serial_Bus_
                                      > <http://www.hardwarebook.info/Universal_Serial_Bus_>>(USB)"
                                      > > > > >
                                      > > > > > Thanks again,
                                      > > > > > Joe
                                      > > > > > W0PWJ
                                      > > > > >
                                      > > > > > -----Original Message-----
                                      > > > > > From: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                                      > > > <mailto:tracker2%40yahoogroups.com>
                                      > > > > > [mailto:tracker2@yahoogroups.com
                                      > <mailto:tracker2%40yahoogroups.com>
                                      > > > > <mailto:tracker2%40yahoogroups.com>] On
                                      > > > > > Behalf Of Scott
                                      > > > > Miller
                                      > > > > > Sent: Saturday, March 08, 2008 4:17 PM
                                      > > > > > To: tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>
                                      > > > <mailto:tracker2%40yahoogroups.com>
                                      > > > > > Subject: Re: [tracker2] Power into Nuvi350 via
                                      > > > FMI cable
                                      > > > > >
                                      > > > > > <snip>...
                                      > > > > >
                                      > > > > > I've got a working substitute circuit, just need
                                      > > > to choose
                                      > > > > the final
                                      > > > > > components I'm going to use and redo my circuit
                                      > > > layout, since I
                                      > > > > > screwed up the first one. It should be small
                                      > > > enough to fit into a
                                      > > > > > standard DB9 shell. Just need to find the dang
                                      > > > USB cables.
                                      > > > > >
                                      > > > > > Scott
                                      > > > > >
                                      > > > > > ...<whack>
                                      > > > > >
                                      > > > > >
                                      > > > >
                                      > > > >
                                      > > > >
                                      > > > >
                                      > > > > Yahoo! Groups Links
                                      > > > >
                                      > > > >
                                      > > > >
                                      > > > >
                                      > > >
                                      > > >
                                      > > > ------------------------------------
                                      > > >
                                      > > > Yahoo! Groups Links
                                      > > >
                                      > > >
                                      > > >
                                      > > >
                                      > > >
                                      > >
                                      > >
                                      > >
                                      > >
                                      > > __________________________________________________________
                                      > > ______________________
                                      > > Never miss a thing. Make Yahoo your home page.
                                      > > http://www.yahoo.com/r/hs <http://www.yahoo.com/r/hs>
                                      > >
                                      > > ------------------------------------
                                      > >
                                      > > Yahoo! Groups Links
                                      > >
                                      > >
                                      > >
                                      >
                                      >
                                    • zl1vfo
                                      ... Well technically it will dissipate the same wattage (P = E x I or (Vin - Vout)/Current Drain), but it should be a bit cooler due to greater surface area.
                                      Message 18 of 23 , Mar 18, 2008
                                        --- In tracker2@yahoogroups.com, "Joe Krout" <jkrout@...> wrote:
                                        >
                                        > Scott,
                                        > Do you foresee any problem if I replace the 78m05 with a 7805 regualtor?
                                        > I remember you mentioning that the current draw to the NUVI through a
                                        > modifed FMI cable was close to the limit for the 78m05 at 12 volts.
                                        > Thought maybe a change to a 1 amp regulator would reduce heating.
                                        >
                                        > Thanks
                                        > Joe W0PWJ
                                        >

                                        Well technically it will dissipate the same wattage (P = E x I or (Vin
                                        - Vout)/Current Drain), but it should be a bit cooler due to greater
                                        surface area. If you know the current drain from the 7805, we can work
                                        out how hot the 7805 will get. If you have a maximum temperature for
                                        the heatsink you want to mount it on, we can also figure out how big
                                        (or small) the heatsink will need to be.

                                        73,
                                        Ian ZL1VFO
                                      • zl1vfo
                                        ... ~ Snip ~ ... ~ Snap ~ Scott, any chance of a (very) rough drawing of how you ve wired that up? Even if it s a snapshot of a diagram drawn with a sharpie on
                                        Message 19 of 23 , Mar 18, 2008
                                          --- In tracker2@yahoogroups.com, Scott Miller <scott@...> wrote:
                                          ~ Snip ~

                                          > All you really need is a 5-conductor USB cable (good luck), a couple of
                                          > 8.2k resistors, and a couple of diodes. The data in (from GPS to T2)
                                          > doesn't need anything done to it at all. The data out needs to be
                                          > limited to 0-3.3 volts. I did that with a series diode and a string of
                                          > diodes to ground since I didn't have a zener in the 3.3 volt range.
                                          > One resistor goes between the extra USB pin (the one that doesn't
                                          > have a number in the USB spec) and ground. The other resistor goes
                                          > between the T2 and the diodes to limit the current.

                                          ~ Snap ~

                                          Scott, any chance of a (very) rough drawing of how you've wired that up?
                                          Even if it's a snapshot of a diagram drawn with a sharpie on the back
                                          of a napkin, I'd be interested. I've been playing with a(nother)
                                          simple Schematic and PCB drawing program,(expresspcb) & a simple
                                          circuit like that looks ideal to draw up & drop in the files section.

                                          Also, a blue or a pair of red LEDs should make a good 3.3V Zener -
                                          also indicates when data's going past, too...

                                          73,
                                          Ian ZL1VFO
                                        • dondorgram
                                          Re: Power into Nuvi350 via FMI cable While I m kind of sorry I opened up a bag of worms with the question, I did get some answers from Scott and others which
                                          Message 20 of 23 , Mar 19, 2008
                                            Re: Power into Nuvi350 via FMI cable


                                            While I'm kind of sorry I opened up a bag of worms with the
                                            question, I did get some answers from Scott and others which saved
                                            me some trouble. Here is a summary of my experiments.

                                            I did the same as Joe using an extra cable I had cut to total length
                                            of about 4 feet. I tapped into the miniUSB side of the "bump" but
                                            ran the +5 volt wire all the way to the 9pin serial connector rather
                                            than tap into the serial side of the bump (used short lengths of
                                            heatshrink to bind it to the cable) so I could monitor current to
                                            the Nuvi. By the way the red wire in the cable is fairly fine (say
                                            #22 or smaller), so needs to be handled carefully

                                            Before everyone does this, I would reaffirm the disclaimers given by
                                            Joe W0PWJ! Be aware that the Nuvi recharges its battery through
                                            the connection and current could be high as a result. I did some
                                            quick checks and found current could be as high as 400mA into the
                                            12V to 5V cigarette lighter adapter/regulator when using the rear
                                            miniUSB when the battery was charging (peak was about 300 using side
                                            connector - current limiting? -but see below) - quiescent current
                                            for the adapter is about 14mA. Current could go as low as 110 mA
                                            when charged (compared to 55mA in the GPSMAP60CSx which does not
                                            charge through the serial cable), but could vary from 110 mA up,
                                            depending on state of battery.

                                            The 78M05 in the OT2m might be an issue if full current was being
                                            drawn. It is rated at about 500mA but problem is power
                                            dissipation. Thus with 300 mA x (say)8V drop, power dissipated is
                                            2.4 W. I'm not sure about the actual package used (is it a DPAK or
                                            DPAK2, or what?), or configuration of vias to the back plane, etc.
                                            Looking at various specs the best that could be achieved looks to be
                                            2 to 3 W with moderate pad size.

                                            I elected to try the cable out on a ProtoC with the 7805T as I can
                                            always fix it if it breaks. The T0-220 package can normally handle
                                            up to 20w with finned heatsinks but good for a few watts with
                                            moderate sinking.

                                            With the miniUSB plugged into the Nuvi I applied power to the OT2.
                                            There is typically a spike of 400mA before it settles down to 250mA
                                            or less. This current is enough to make the 78T05 fairly warm.
                                            As I don't like to stress components, I played around with series 2
                                            watt 10-15 ohm resistors to drop the voltage to the regulator and
                                            settled on 12 ohm.

                                            I found that occassionally if I powered up the OT2 first and then
                                            plugged in the miniUSB into the Nuvi, the current stayed at 400mA!
                                            If I cycled power to the OT2, it would settle down to the lower
                                            current. I can't account for this latchup of the current, but
                                            might have something to do with the power-on sequence the circuit
                                            the "bump" wants to see. Normally it would see the power coming
                                            from the Nuvi after the connection is made. With power to the cable
                                            it is always on.

                                            Obviously in latchup the power dissipated in the OT2 would be 400mA
                                            x 8 V = 3.2W. Probably not good for the 78M05 in the OT2m, but OK
                                            for the TO-220 package, especially with a dropping resistor. I
                                            also wonder what the effect of high current is to the cable or the
                                            Nuvi. It's not all going to charge the battery, so might be
                                            cooking something in the "bump".

                                            I've tried this out numerous times over the last few days, and get
                                            inconsistant results. But it will regularly latch up if the miniUSB
                                            is attached last. Needless to say I did not allow it to stay in
                                            this mode too long.

                                            While the 78M05 and the 7805T both have internal power limiting, I
                                            don't think I would like to see the unit shut down in the middle of
                                            a balloon chase or event, so until I (or others) can explain this, I
                                            think I will stick to using the power cable to the back of the Nuvi.

                                            Graham VE6GW



                                            --- In tracker2@yahoogroups.com, Scott Miller <scott@...> wrote:
                                            >
                                            > The red wire coming from the USB side powers the converter
                                            circuit, but
                                            > it doesn't go anywhere else.
                                            >
                                            > All you really need is a 5-conductor USB cable (good luck), a
                                            couple of
                                            > 8.2k resistors, and a couple of diodes. The data in (from GPS to
                                            T2)
                                            > doesn't need anything done to it at all. The data out needs to be
                                            > limited to 0-3.3 volts. I did that with a series diode and a
                                            string of
                                            > diodes to ground since I didn't have a zener in the 3.3 volt
                                            range. One
                                            > resistor goes between the extra USB pin (the one that doesn't have
                                            a
                                            > number in the USB spec) and ground. The other resistor goes
                                            between the
                                            > T2 and the diodes to limit the current.
                                            >
                                            > Scott
                                            >
                                            > Joe Krout wrote:
                                            > >
                                            > >
                                            > > I checked that possibility with an ohm meter. The red wire does
                                            not
                                            > > pass through the Garmin "bump" in the cable. Not sure if it is
                                            tied to
                                            > > anything in the bump, that is why I cut it on the serial side and
                                            > > insulated the stub going into the bump. By teeing it on the USB
                                            side, I
                                            > > am sending 5 volts to the bump and to the Nuvi.
                                            > > Probably worth mentioning that the power cord to the back of the
                                            NUVI
                                            > > should not be used with the modified FMI cable. Also, the FMI
                                            cable
                                            > > (modified or not) must be plugged into the side USB port. My
                                            primary
                                            > > reason for making the mod was to eliminate the cigarette lighter
                                            plug
                                            > > and the second cable. Makes wiring my Go Box much easier.
                                            > >
                                            > > Joe
                                            > > W0PWJ
                                            > >
                                            > > > -----Original Message-----
                                            > > > From: tracker2@yahoogroups.com <mailto:tracker2%
                                            40yahoogroups.com>
                                            > > > [mailto:tracker2@yahoogroups.com <mailto:tracker2%
                                            40yahoogroups.com>]
                                            > > On Behalf Of P. Suryono Adisoemarta
                                            > > > Sent: Sunday, March 16, 2008 9:10 PM
                                            > > > To: tracker2@yahoogroups.com <mailto:tracker2%
                                            40yahoogroups.com>
                                            > > > Subject: RE: [tracker2] Power into Nuvi350 via FMI cable
                                            > > >
                                            > > >
                                            > > >
                                            > > > I was thinking that you can skip slicing the red wire
                                            > > > at the mini-USB side, and just sliced the red wire at
                                            > > > the DB9 to hook to Pin 4 on the serial port.
                                            > > >
                                            > > > de N5SNN
                                            > > >
                                            > > >
                                            > > >
                                            > > > --- Joe Krout <jkrout@... <mailto:jkrout%40gmail.com>> wrote:
                                            > > >
                                            > > > > Well, I couldn't take it any longer.
                                            > > > > I now have a FMI cable that supplies power to the
                                            > > > > NUVI from the OT2m!
                                            > > > > I am working on a Go box for the NUVI and the OTM2
                                            > > > > with a
                                            > > > >
                                            > > > > This is what I did.
                                            > > > >
                                            > > > > The information provided is for educational purposes
                                            > > > > only.
                                            > > > > I am NOT a trained professional. I did try this at
                                            > > > > home.
                                            > > > > No, I did not take any pictures, I already know what
                                            > > > > I look like.
                                            > > > > Should you choose to attempt this proceed at your
                                            > > > > own risk.
                                            > > > > I will not take any responsibility for your actions.
                                            > > > >
                                            > > > >
                                            > > > > I carefully sliced open the insulation and shielding
                                            > > > > on the FMI cable
                                            > > > > about 2 inches from each side of the Garmin "bump"
                                            > > > > and fished out the
                                            > > > > red wire. I made about a 1 inch long slice axially.
                                            > > > > On the USB side, I soldered a wire in to the red
                                            > > > > wire, without cutting
                                            > > > > the existing wire.
                                            > > > > On the serial side of the "bump" I fished out the
                                            > > > > red wire, cut it in
                                            > > > > two and soldered the other end of the spliced wire
                                            > > > > to the serial side of
                                            > > > > the cut red wire.
                                            > > > > At the serial connector, I verified that I had +5
                                            > > > > volts on pin 4 and
                                            > > > > connected the red wire into it.
                                            > > > > The black ground wire already passes through the
                                            > > > > "bump" to the USB
                                            > > > > connector, (ignore the green wire.)
                                            > > > > I coated the slices in the cable with liquid plastic
                                            > > > > and taped over
                                            > > > > everything.
                                            > > > >
                                            > > > > It works for me. Your results may vary.
                                            > > > >
                                            > > > > 73
                                            > > > > Joe W0PWJ
                                            > > > >
                                            > > > >
                                            > > > >
                                            > > > > > -----Original Message-----
                                            > > > > > From: tracker2@yahoogroups.com <mailto:tracker2%
                                            40yahoogroups.com>
                                            > > > > > [mailto:tracker2@yahoogroups.com
                                            > > <mailto:tracker2%40yahoogroups.com>] On Behalf Of
                                            > > > > Scott Miller
                                            > > > > > Sent: Saturday, March 08, 2008 7:36 PM
                                            > > > > > To: tracker2@yahoogroups.com <mailto:tracker2%
                                            40yahoogroups.com>
                                            > > > > > Subject: Re: [tracker2] Power into Nuvi350 via FMI
                                            > > > > cable
                                            > > > > >
                                            > > > > >
                                            > > > > > Which extra wire?
                                            > > > > >
                                            > > > > > The extra contact on the 5-pin mini-B connector is
                                            > > > > an 8.2k
                                            > > > > > resistor to
                                            > > > > > ground that it uses to sense the serial accessory
                                            > > > > cable. Not the
                                            > > > > > standard OTG arrangement, apparently.
                                            > > > > >
                                            > > > > > Aside from that, it's just +5v, GND, D-, and D+.
                                            > > > > >
                                            > > > > > Scott
                                            > > > > >
                                            > > > > > Joe Krout wrote:
                                            > > > > > >
                                            > > > > > >
                                            > > > > > > Have you determined what the extra wire is?
                                            > > > > > > The attached links talk about an ID Pin that is
                                            > > > > grounded making the
                                            > > > > > > mini-b, a mini-a connector. This is done to
                                            > > > > implement the
                                            > > > > > "USB on the
                                            > > > > > > go" standard that allows to devices to
                                            > > > > communicate without a "host"
                                            > > > > > > PC. My guess is that the Nuvi is at the "A" end
                                            > > > > and the
                                            > > > > > interface is
                                            > > > > > > the B end. I think you mentioned a resistor in
                                            > > > > the cable somewhere?
                                            > > > > > > Did it go to ground?
                                            > > > > > >
                                            > > > >
                                            > > > "http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/
                                            > > <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/>
                                            > > > > > >
                                            > > > >
                                            > > > <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/
                                            > > <http://www.maxim-ic.com/appnotes.cfm/appnote_number/1822/>>"
                                            > > > > > >
                                            > > > > "http://www.hardwarebook.info/Universal_Serial_Bus_
                                            > > <http://www.hardwarebook.info/Universal_Serial_Bus_>
                                            > > > > > >
                                            > > > >
                                            > > > <http://www.hardwarebook.info/Universal_Serial_Bus_
                                            > > <http://www.hardwarebook.info/Universal_Serial_Bus_>>(USB)"
                                            > > > > > >
                                            > > > > > > Thanks again,
                                            > > > > > > Joe
                                            > > > > > > W0PWJ
                                            > > > > > >
                                            > > > > > > -----Original Message-----
                                            > > > > > > From: tracker2@yahoogroups.com <mailto:tracker2%
                                            40yahoogroups.com>
                                            > > > > <mailto:tracker2%40yahoogroups.com>
                                            > > > > > > [mailto:tracker2@yahoogroups.com
                                            > > <mailto:tracker2%40yahoogroups.com>
                                            > > > > > <mailto:tracker2%40yahoogroups.com>] On
                                            > > > > > > Behalf Of Scott
                                            > > > > > Miller
                                            > > > > > > Sent: Saturday, March 08, 2008 4:17 PM
                                            > > > > > > To: tracker2@yahoogroups.com <mailto:tracker2%
                                            40yahoogroups.com>
                                            > > > > <mailto:tracker2%40yahoogroups.com>
                                            > > > > > > Subject: Re: [tracker2] Power into Nuvi350 via
                                            > > > > FMI cable
                                            > > > > > >
                                            > > > > > > <snip>...
                                            > > > > > >
                                            > > > > > > I've got a working substitute circuit, just need
                                            > > > > to choose
                                            > > > > > the final
                                            > > > > > > components I'm going to use and redo my circuit
                                            > > > > layout, since I
                                            > > > > > > screwed up the first one. It should be small
                                            > > > > enough to fit into a
                                            > > > > > > standard DB9 shell. Just need to find the dang
                                            > > > > USB cables.
                                            > > > > > >
                                            > > > > > > Scott
                                            > > > > > >
                                            > > > > > > ...<whack>
                                            > > > > > >
                                            > > > > > >
                                            > > > > >
                                            > > > > >
                                            > > > > >
                                            > > > > >
                                            > > > > > Yahoo! Groups Links
                                            > > > > >
                                            > > > > >
                                            > > > > >
                                            > > > > >
                                            > > > >
                                            > > > >
                                            > > > > ------------------------------------
                                            > > > >
                                            > > > > Yahoo! Groups Links
                                            > > > >
                                            > > > >
                                            > > > >
                                            > > > >
                                            > > > >
                                            > > >
                                            > > >
                                            > > >
                                            > > >
                                            > > > __________________________________________________________
                                            > > > ______________________
                                            > > > Never miss a thing. Make Yahoo your home page.
                                            > > > http://www.yahoo.com/r/hs <http://www.yahoo.com/r/hs>
                                            > > >
                                            > > > ------------------------------------
                                            > > >
                                            > > > Yahoo! Groups Links
                                            > > >
                                            > > >
                                            > > >
                                            > >
                                            > >
                                            >
                                          • Scott Miller
                                            ... It s a DPAK (TO-252). There are six 24 mil thermal vias to the back plane. There s a lot of copper area on the bottom layer, and maybe 1 by 0.3 on the
                                            Message 21 of 23 , Mar 19, 2008
                                              > 2.4 W. I'm not sure about the actual package used (is it a DPAK or
                                              > DPAK2, or what?), or configuration of vias to the back plane, etc.
                                              > Looking at various specs the best that could be achieved looks to be
                                              > 2 to 3 W with moderate pad size.

                                              It's a DPAK (TO-252). There are six 24 mil thermal vias to the back
                                              plane. There's a lot of copper area on the bottom layer, and maybe 1"
                                              by 0.3" on the top.

                                              > current. I can't account for this latchup of the current, but
                                              > might have something to do with the power-on sequence the circuit
                                              > the "bump" wants to see. Normally it would see the power coming
                                              > from the Nuvi after the connection is made. With power to the cable
                                              > it is always on.

                                              The 'bump' contains a 3-lead regulator, RS-232 transceiver, and
                                              inverter. I don't think that's the source of the excess current.

                                              I wonder if it'd help to have a little copper leaf attached to the lid
                                              that'd press against the regulator and act as a heat sink...

                                              Scott
                                            • dondorgram
                                              Thanks Scott: Looking at the National Semiconductor spec sheet for the LM78M05, figure 5 gives power dissipation vs surface area of 2oz copper. Top plane area
                                              Message 22 of 23 , Mar 19, 2008
                                                Thanks Scott:

                                                Looking at the National Semiconductor spec sheet for the LM78M05,
                                                figure 5 gives power dissipation vs surface area of 2oz copper. Top
                                                plane area seems to more critial and has to be over .8 sq in to sink
                                                2 Watts. With the smaller top area of copper used on the OT2m, it
                                                looks like maximum power is around 1.8W even if the bottom Cu area
                                                is relatively large. Might not be strictly applicable to the device
                                                you used, but is a fair indication.

                                                A copper leaf attached to the lid would be a bit problematical the
                                                way the lid fits on now. Any finned heatsink available that could
                                                fit under the D-PAK? But is it worth it just to be a battery
                                                charger for a Nuvi?

                                                To bug you again, can you post a quick sketch of the "bump"
                                                circuit? Would be interesting to play around with it.

                                                Oh, and one other thing. Another reason I chose the ProtoC, was
                                                that I could identify the Thermistor in the 12V line; but the OT2m
                                                has a component R18 indicated as 200mA on the schematic. It is
                                                stamped "4 I" of "4 i". Is this a SMT Thermistor? Or is it a fuse?

                                                Once again, thanks for designing all this fun stuff for us to play
                                                with.

                                                Graham VE6GW


                                                --- In tracker2@yahoogroups.com, Scott Miller <scott@...> wrote:
                                                >
                                                > > 2.4 W. I'm not sure about the actual package used (is it a DPAK
                                                or
                                                > > DPAK2, or what?), or configuration of vias to the back plane,
                                                etc.
                                                > > Looking at various specs the best that could be achieved looks
                                                to be
                                                > > 2 to 3 W with moderate pad size.
                                                >
                                                > It's a DPAK (TO-252). There are six 24 mil thermal vias to the
                                                back
                                                > plane. There's a lot of copper area on the bottom layer, and
                                                maybe 1"
                                                > by 0.3" on the top.
                                                >
                                                > > current. I can't account for this latchup of the current, but
                                                > > might have something to do with the power-on sequence the circuit
                                                > > the "bump" wants to see. Normally it would see the power coming
                                                > > from the Nuvi after the connection is made. With power to the
                                                cable
                                                > > it is always on.
                                                >
                                                > The 'bump' contains a 3-lead regulator, RS-232 transceiver, and
                                                > inverter. I don't think that's the source of the excess current.
                                                >
                                                > I wonder if it'd help to have a little copper leaf attached to the
                                                lid
                                                > that'd press against the regulator and act as a heat sink...
                                                >
                                                > Scott
                                                >
                                              • Scott Miller
                                                I ll see if I can find my sketches of the circuit. I also have some pictures of the board from my microscope camera. R18 is a thermistor. I ve branded an
                                                Message 23 of 23 , Mar 19, 2008
                                                  I'll see if I can find my sketches of the circuit. I also have some
                                                  pictures of the board from my microscope camera.

                                                  R18 is a thermistor. I've branded an imprint of it into my fingertip
                                                  before when the power has shorted. =]

                                                  Scott

                                                  dondorgram wrote:
                                                  >
                                                  >
                                                  > Thanks Scott:
                                                  >
                                                  > Looking at the National Semiconductor spec sheet for the LM78M05,
                                                  > figure 5 gives power dissipation vs surface area of 2oz copper. Top
                                                  > plane area seems to more critial and has to be over .8 sq in to sink
                                                  > 2 Watts. With the smaller top area of copper used on the OT2m, it
                                                  > looks like maximum power is around 1.8W even if the bottom Cu area
                                                  > is relatively large. Might not be strictly applicable to the device
                                                  > you used, but is a fair indication.
                                                  >
                                                  > A copper leaf attached to the lid would be a bit problematical the
                                                  > way the lid fits on now. Any finned heatsink available that could
                                                  > fit under the D-PAK? But is it worth it just to be a battery
                                                  > charger for a Nuvi?
                                                  >
                                                  > To bug you again, can you post a quick sketch of the "bump"
                                                  > circuit? Would be interesting to play around with it.
                                                  >
                                                  > Oh, and one other thing. Another reason I chose the ProtoC, was
                                                  > that I could identify the Thermistor in the 12V line; but the OT2m
                                                  > has a component R18 indicated as 200mA on the schematic. It is
                                                  > stamped "4 I" of "4 i". Is this a SMT Thermistor? Or is it a fuse?
                                                  >
                                                  > Once again, thanks for designing all this fun stuff for us to play
                                                  > with.
                                                  >
                                                  > Graham VE6GW
                                                  >
                                                  > --- In tracker2@yahoogroups.com <mailto:tracker2%40yahoogroups.com>,
                                                  > Scott Miller <scott@...> wrote:
                                                  > >
                                                  > > > 2.4 W. I'm not sure about the actual package used (is it a DPAK
                                                  > or
                                                  > > > DPAK2, or what?), or configuration of vias to the back plane,
                                                  > etc.
                                                  > > > Looking at various specs the best that could be achieved looks
                                                  > to be
                                                  > > > 2 to 3 W with moderate pad size.
                                                  > >
                                                  > > It's a DPAK (TO-252). There are six 24 mil thermal vias to the
                                                  > back
                                                  > > plane. There's a lot of copper area on the bottom layer, and
                                                  > maybe 1"
                                                  > > by 0.3" on the top.
                                                  > >
                                                  > > > current. I can't account for this latchup of the current, but
                                                  > > > might have something to do with the power-on sequence the circuit
                                                  > > > the "bump" wants to see. Normally it would see the power coming
                                                  > > > from the Nuvi after the connection is made. With power to the
                                                  > cable
                                                  > > > it is always on.
                                                  > >
                                                  > > The 'bump' contains a 3-lead regulator, RS-232 transceiver, and
                                                  > > inverter. I don't think that's the source of the excess current.
                                                  > >
                                                  > > I wonder if it'd help to have a little copper leaf attached to the
                                                  > lid
                                                  > > that'd press against the regulator and act as a heat sink...
                                                  > >
                                                  > > Scott
                                                  > >
                                                  >
                                                  >
                                                Your message has been successfully submitted and would be delivered to recipients shortly.