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

Older Serial port equipment to Pi info

Expand Messages
  • w8iss
    Hello everyone. I am wondering if anyone can suggest how to interface older serial port (db-9) to the GPIO pins properly? I have been warned about watching the
    Message 1 of 9 , Dec 14, 2013
      Hello everyone.

      I am wondering if anyone can suggest how to interface older serial port (db-9) to the GPIO pins properly?

      I have been warned about watching the voltage leveles and have been told about 3.3, 5, and 12(?) volt levels but am not familiar with them so I am cautious about what and how I connect till I know more.

      I also know that there is ways to go from serial to ttl levels (Icom CI-V, ARRL handbook level convertors. This got me thinking about since the Pi has a TTL level outputs that I know of, could I control my ICOM IC-820h 2m/70cm all-mode directly without the CI-V interface or is this another voltage level concern?

      Reason I ask about the voltages is that I have a ICOM pcr-100 sitting here that I want to ustilize with the software WXTOIMG on a Pi if possible.

      Thanks in advance :)

      James W8ISS
      EN82jg
    • Mike Heitmann
      Hi James, I ve used these to go from a Raspberry Pi serial port to standard RS-232: https://www.sparkfun.com/products/11189 If you re going to an ICOM CIV you
      Message 2 of 9 , Dec 25, 2013
        Hi James,

        I've used these to go from a Raspberry Pi serial port to standard RS-232:

        If you're going to an ICOM CIV you could probably get away with a level converter like this one:

        Merry Christmas, hope this helps.

        Mike, N0SO

        On Dec 14, 2013, at 8:28 AM, <w8iss1@...> wrote:

         

        Hello everyone.

        I am wondering if anyone can suggest how to interface older serial port (db-9) to the GPIO pins properly?

        I have been warned about watching the voltage leveles and have been told about 3.3, 5, and 12(?) volt levels but am not familiar with them so I am cautious about what and how I connect till I know more.

        I also know that there is ways to go from serial to ttl levels (Icom CI-V, ARRL handbook level convertors. This got me thinking about since the Pi has a TTL level outputs that I know of, could I control my ICOM IC-820h 2m/70cm all-mode directly without the CI-V interface or is this another voltage level concern?

        Reason I ask about the voltages is that I have a ICOM pcr-100 sitting here that I want to ustilize with the software WXTOIMG on a Pi if possible.

        Thanks in advance :)

        James W8ISS
        EN82jg

      • Scott Roberts - KK4ECR
        This may help...new expansion board for Raspberry Pi... http://kk4ecr.us/wp/raspberry-pi-expansion/ Sent from my iPhone
        Message 3 of 9 , Dec 26, 2013
          This may help...new expansion board for Raspberry Pi...


          On Dec 25, 2013, at 10:38 PM, Mike Heitmann <n0so@...> wrote:

           

          Hi James,

          I've used these to go from a Raspberry Pi serial port to standard RS-232:

          If you're going to an ICOM CIV you could probably get away with a level converter like this one:

          Merry Christmas, hope this helps.

          Mike, N0SO

          On Dec 14, 2013, at 8:28 AM, <w8iss1@...> wrote:

           

          Hello everyone.

          I am wondering if anyone can suggest how to interface older serial port (db-9) to the GPIO pins properly?

          I have been warned about watching the voltage leveles and have been told about 3.3, 5, and 12(?) volt levels but am not familiar with them so I am cautious about what and how I connect till I know more.

          I also know that there is ways to go from serial to ttl levels (Icom CI-V, ARRL handbook level convertors. This got me thinking about since the Pi has a TTL level outputs that I know of, could I control my ICOM IC-820h 2m/70cm all-mode directly without the CI-V interface or is this another voltage level concern?

          Reason I ask about the voltages is that I have a ICOM pcr-100 sitting here that I want to ustilize with the software WXTOIMG on a Pi if possible.

          Thanks in advance :)

          James W8ISS
          EN82jg

        • CyclingSoldier
          Please, keep us posted on your experiments with this. If it works well, they may have at least one more sold. V/r Jack KE4LWT From:
          Message 4 of 9 , Dec 26, 2013

            Please, keep us posted on your experiments with this. If it works well, they may have at least one more sold.

             

            V/r

            Jack KE4LWT

             

            From: Raspberry_Pi_4-Ham_RADIO@yahoogroups.com [mailto:Raspberry_Pi_4-Ham_RADIO@yahoogroups.com] On Behalf Of Scott Roberts - KK4ECR
            Sent: Thursday, December 26, 2013 5:50 AM
            To: Raspberry_Pi_4-Ham_RADIO@yahoogroups.com
            Subject: Re: [Raspberry_Pi_4-Ham_RADIO] Older Serial port equipment to Pi info

             

             

            This may help...new expansion board for Raspberry Pi...

             


            On Dec 25, 2013, at 10:38 PM, Mike Heitmann <n0so@...> wrote:

             

            Hi James,

             

            I've used these to go from a Raspberry Pi serial port to standard RS-232:

             

            If you're going to an ICOM CIV you could probably get away with a level converter like this one:

             

            Merry Christmas, hope this helps.

             

            Mike, N0SO


            On Dec 14, 2013, at 8:28 AM, <w8iss1@...> wrote:

             

            Hello everyone.

            I am wondering if anyone can suggest how to interface older serial port (db-9) to the GPIO pins properly?

            I have been warned about watching the voltage leveles and have been told about 3.3, 5, and 12(?) volt levels but am not familiar with them so I am cautious about what and how I connect till I know more.

            I also know that there is ways to go from serial to ttl levels (Icom CI-V, ARRL handbook level convertors. This got me thinking about since the Pi has a TTL level outputs that I know of, could I control my ICOM IC-820h 2m/70cm all-mode directly without the CI-V interface or is this another voltage level concern?

            Reason I ask about the voltages is that I have a ICOM pcr-100 sitting here that I want to ustilize with the software WXTOIMG on a Pi if possible.

            Thanks in advance :)

            James W8ISS
            EN82jg

          • Ronny Julian
            What did they cost you? I looked on most of the page and saw no prices. Looks like exactly what I need. Now I need to make a new taller case! Ronny K4RJJ
            Message 5 of 9 , Dec 26, 2013
              What did they cost you?  I looked on most of the page and saw no prices.  Looks like exactly what I need.  Now I need to make a new taller case!
              Ronny
              K4RJJ



              On Thu, Dec 26, 2013 at 5:50 AM, Scott Roberts - KK4ECR <kk4ecr@...> wrote:
               

              This may help...new expansion board for Raspberry Pi...


              On Dec 25, 2013, at 10:38 PM, Mike Heitmann <n0so@...> wrote:

               

              Hi James,

              I've used these to go from a Raspberry Pi serial port to standard RS-232:

              If you're going to an ICOM CIV you could probably get away with a level converter like this one:

              Merry Christmas, hope this helps.

              Mike, N0SO

              On Dec 14, 2013, at 8:28 AM, <w8iss1@...> wrote:

               

              Hello everyone.

              I am wondering if anyone can suggest how to interface older serial port (db-9) to the GPIO pins properly?

              I have been warned about watching the voltage leveles and have been told about 3.3, 5, and 12(?) volt levels but am not familiar with them so I am cautious about what and how I connect till I know more.

              I also know that there is ways to go from serial to ttl levels (Icom CI-V, ARRL handbook level convertors. This got me thinking about since the Pi has a TTL level outputs that I know of, could I control my ICOM IC-820h 2m/70cm all-mode directly without the CI-V interface or is this another voltage level concern?

              Reason I ask about the voltages is that I have a ICOM pcr-100 sitting here that I want to ustilize with the software WXTOIMG on a Pi if possible.

              Thanks in advance :)

              James W8ISS
              EN82jg


            • Ronny Julian
              Nevermind. Tried the DX link. Selling my spider of junk and cables on eBay. This is great!
              Message 6 of 9 , Dec 26, 2013
                Nevermind.  Tried the DX link.  Selling my spider of junk and cables on eBay.   This is great!



                On Thu, Dec 26, 2013 at 7:38 PM, Ronny Julian <k4rjjradio@...> wrote:
                What did they cost you?  I looked on most of the page and saw no prices.  Looks like exactly what I need.  Now I need to make a new taller case!
                Ronny
                K4RJJ



                On Thu, Dec 26, 2013 at 5:50 AM, Scott Roberts - KK4ECR <kk4ecr@...> wrote:
                 

                This may help...new expansion board for Raspberry Pi...


                On Dec 25, 2013, at 10:38 PM, Mike Heitmann <n0so@...> wrote:

                 

                Hi James,

                I've used these to go from a Raspberry Pi serial port to standard RS-232:

                If you're going to an ICOM CIV you could probably get away with a level converter like this one:

                Merry Christmas, hope this helps.

                Mike, N0SO

                On Dec 14, 2013, at 8:28 AM, <w8iss1@...> wrote:

                 

                Hello everyone.

                I am wondering if anyone can suggest how to interface older serial port (db-9) to the GPIO pins properly?

                I have been warned about watching the voltage leveles and have been told about 3.3, 5, and 12(?) volt levels but am not familiar with them so I am cautious about what and how I connect till I know more.

                I also know that there is ways to go from serial to ttl levels (Icom CI-V, ARRL handbook level convertors. This got me thinking about since the Pi has a TTL level outputs that I know of, could I control my ICOM IC-820h 2m/70cm all-mode directly without the CI-V interface or is this another voltage level concern?

                Reason I ask about the voltages is that I have a ICOM pcr-100 sitting here that I want to ustilize with the software WXTOIMG on a Pi if possible.

                Thanks in advance :)

                James W8ISS
                EN82jg



              • wa5bdu
                You definitely need a converter since standard RS232 has logic 1 at -5 to -15 VDC and logic 0 at +5 to +15 VDC, based on memory. But the key is that it s
                Message 7 of 9 , Dec 26, 2013

                  You definitely need a converter since standard RS232 has logic 1 at -5 to -15 VDC and logic 0 at +5 to +15 VDC, based on memory.  But the key is that it's "upside down" from TTL or 3.3 V logic and it has a potentially damaging negative output.


                  If you like to go the eBay route, search MAX3232 and see a lot of little adapters for cheap.  They'll work with 5 V or 3.3V and come with jumpers to allow patching to the 0.1" spaced pins on the Raspi's headers, and have a standard DB9 to go the other way.


                  The ones I bought look kinda like this one:


                  http://www.ebay.com/itm/5V-MAX3232-RS232-Serial-Port-To-TTL-Converter-Module-DB9-Connector-W-4Pin-Cable-/281219306677?pt=LH_DefaultDomain_0&hash=item4179fa14b5


                  Or maybe this one:


                  http://www.ebay.com/itm/2pcs-MAX3232-RS232-Serial-Port-To-TTL-Converter-Module-DB9-Connector-with-cable-/190897161765?pt=LH_DefaultDomain_0&hash=item2c725b8625


                  This stuff you get from eBay / China usually comes with minimal or no documentation.  If there's anything in the ad describing the hookup or ratings, better capture it before it disappears.  


                  Some notes on the adapters I bought pasted below my signature.


                  73-


                  Nick, WA5BDU


                  RS-232 serial adaptors TTL or 3.3 VDC to RS-232


                  I got two from eBay. Only pins 2, 3 and 5 of the DB9 are connected to anything. The chip is a MAX3232, which has two lines in each direction.


                  Here's what I found by continuity:


                  TTL or 3.3 volt output data goes to the TX pin and comes out PIN 2 on the DB9 at RS-232 levels.


                  RS-232 levels come in to PIN 3 on the DB9 and come out on the RX posts on the 0.1” header.


                  Two other convertors are wired:


                  TTL / 3.3 V signal comes to P2-4 and goes out on P2-1 as RS-232 levels

                  RS232 input comes in on P2-2 and goes out on P2-3 as TTL / 3.3 V level logic


                  It's powered by 5V or 3.3V that you connect to the board. I tried 3.3V and measured the RS-232 output levels at about -6 and +6 VDC.


                  Some DB9 pin assignments, for the DTE (PC connector)


                  Looking into the sockets of the female connector, top row right to left is 1, 2, 3, 4, 5 and bottom row right to left is 6, 7, 8, 9


                  Pin 5 Ground

                  Pin 2 Data IN (data to PC)

                  Pin 3 Data OUT (data from PC)

                  Pin 7 RTS (out from PC)


                  The converter I bought is wired with Pin 2 as data out, so it is DCE and connecting it to a PC would require a straight through cable.



                • Tim McDonough N9PUZ
                  I have used the technique described here by Dale Botkin N0XAS in several projects with 5 VDC logic and it works very well.
                  Message 8 of 9 , Dec 28, 2013
                    I have used the technique described here by Dale Botkin N0XAS in several
                    projects with 5 VDC logic and it works very well.

                    <http://www.botkin.org/dale/rs232_interface.htm>

                    I HAVE NOT TRIED IT WITH A 3.3 VDC CIRCUIT. However, if you tied R2 to
                    3.3 VDC instead of 5 VDC it's a good bet I believe.

                    Experiment FIRST, don't risk your R-Pi until you've tried it.

                    73,

                    Tim N9PUZ
                  • g8jhe
                    Sorry I haven t responded before, have only just joined the group :) There is a version of the MAX232, numbered MAX3232, that is designed for use on the 3.3V
                    Message 9 of 9 , Jan 5, 2014
                      Sorry I haven't responded before, have only just joined the group :)

                      There is a version of the MAX232, numbered MAX3232, that is designed for use on the 3.3V logic levels and supply rail used in the PI. Would suggest using that instead of the original version..........

                      Mike, g8jhe
                    Your message has been successfully submitted and would be delivered to recipients shortly.