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overreacting ?

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  • Lasse Madsen
    Hi all I have 2 questions: Question 1 Im building a power supply to my project ... It draws about 550mA in peaks I have a 6-0-6 Trafo which i full wave rectify
    Message 1 of 10 , Jun 2, 2001
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      Hi all
       
      I have 2 questions:
       
      Question 1
       
      Im building a power supply to my project ...
      It draws about 550mA in peaks
       
      I have a 6-0-6 Trafo which i full wave rectify the old ( 2 diode way )
       
      this circuit delivers a voltage of 11,5 volt but will some ripple ofcause
       
      now i have a 7805 ( TO-220 capsule ) wich i connect to the 11,5V
       
      BUT ! here comes my trouble
       
      If i calculate the loss effect of the 7805 its wery high
      11,5 - 5 * 550mA = 3,75 W
       
      I have a small cooling plate wich should treat this problem
      but what about the ripple will this have any effect on the 16F84 ???
       
       
      Question 2
       
      Is it possible to hard reset the pic ?
       
      i have the following jal code:
       
      please note that pin_a1 and pin_a2 are connected to a normal on/off button not a momentary button
       
      if pin_a1 == high then
      forever loop
      pin_b0 = on
      delay_1s ( 1 )
      pin_b0 = off
      delay_1s ( 1 )
      end loop
      end if
       
      if pin_a2 == high then
      forever loop
      pin_b0 = on
      delay_1s ( 2 )
      pin_b0 = off
      delay_1s ( 2 )
      end loop
      end if
       
       
      and if i then set pin_a1 to low and pin_2 to high and press the reset button (/MCLR) the program continues as before with out notice !
       
      But if i however turn the power on / off from the pic it does as its supposted to
       
      Is there a way to "Hard reset" the PIC ?
      possibly by connecting the Vcc to a momentary button via a resistor to ground and then make a hard reset ?`?
       
      Thanks for any support
       
      Lasse Madsen
       
       
       
       
       
       
       
       
      M.v.h.
      Lasse Madsen
      Højrupsvej 52, 2.m.f.
      9900 Frederikshavn
    • Branko Karaklajiæ
      Did you put resistor from /MCLR to Vcc? pozdrav ... Branko Karaklajic branek@eunet.yu http://solair.eunet.yu/~branek ... From: Lasse Madsen To:
      Message 2 of 10 , Jun 2, 2001
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        Did you put resistor from /MCLR to Vcc?
         
        pozdrav
        -------------------------------------------------
        Branko Karaklajic
        branek@...
        http://solair.eunet.yu/~branek
        ----- Original Message -----
        Sent: Saturday, June 02, 2001 7:52 PM
        Subject: [jallist] overreacting ?

        Hi all
         
        I have 2 questions:
         
        Question 1
         
        Im building a power supply to my project ...
        It draws about 550mA in peaks
         
        I have a 6-0-6 Trafo which i full wave rectify the old ( 2 diode way )
         
        this circuit delivers a voltage of 11,5 volt but will some ripple ofcause
         
        now i have a 7805 ( TO-220 capsule ) wich i connect to the 11,5V
         
        BUT ! here comes my trouble
         
        If i calculate the loss effect of the 7805 its wery high
        11,5 - 5 * 550mA = 3,75 W
         
        I have a small cooling plate wich should treat this problem
        but what about the ripple will this have any effect on the 16F84 ???
         
         
        Question 2
         
        Is it possible to hard reset the pic ?
         
        i have the following jal code:
         
        please note that pin_a1 and pin_a2 are connected to a normal on/off button not a momentary button
         
        if pin_a1 == high then
        forever loop
        pin_b0 = on
        delay_1s ( 1 )
        pin_b0 = off
        delay_1s ( 1 )
        end loop
        end if
         
        if pin_a2 == high then
        forever loop
        pin_b0 = on
        delay_1s ( 2 )
        pin_b0 = off
        delay_1s ( 2 )
        end loop
        end if
         
         
        and if i then set pin_a1 to low and pin_2 to high and press the reset button (/MCLR) the program continues as before with out notice !
         
        But if i however turn the power on / off from the pic it does as its supposted to
         
        Is there a way to "Hard reset" the PIC ?
        possibly by connecting the Vcc to a momentary button via a resistor to ground and then make a hard reset ?`?
         
        Thanks for any support
         
        Lasse Madsen
         
         
         
         
         
         
         
         
        M.v.h.
        Lasse Madsen
        Højrupsvej 52, 2.m.f.
        9900 Frederikshavn


        Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
      • Lasse Madsen
        yes a 4K7 and the chip resets in all other codes than a forever loop - code ... From: Branko Karaklajiæ To: jallist@yahoogroups.com Sent: Saturday, June 02,
        Message 3 of 10 , Jun 2, 2001
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          yes a 4K7
           
          and the chip resets in all other codes than a
           
          forever loop - code
           
          ----- Original Message -----
          Sent: Saturday, June 02, 2001 11:43 PM
          Subject: Re: [jallist] overreacting ?

          Did you put resistor from /MCLR to Vcc?
           
          pozdrav
          -------------------------------------------------
          Branko Karaklajic
          branek@...
          http://solair.eunet.yu/~branek
          ----- Original Message -----
          Sent: Saturday, June 02, 2001 7:52 PM
          Subject: [jallist] overreacting ?

          Hi all
           
          I have 2 questions:
           
          Question 1
           
          Im building a power supply to my project ...
          It draws about 550mA in peaks
           
          I have a 6-0-6 Trafo which i full wave rectify the old ( 2 diode way )
           
          this circuit delivers a voltage of 11,5 volt but will some ripple ofcause
           
          now i have a 7805 ( TO-220 capsule ) wich i connect to the 11,5V
           
          BUT ! here comes my trouble
           
          If i calculate the loss effect of the 7805 its wery high
          11,5 - 5 * 550mA = 3,75 W
           
          I have a small cooling plate wich should treat this problem
          but what about the ripple will this have any effect on the 16F84 ???
           
           
          Question 2
           
          Is it possible to hard reset the pic ?
           
          i have the following jal code:
           
          please note that pin_a1 and pin_a2 are connected to a normal on/off button not a momentary button
           
          if pin_a1 == high then
          forever loop
          pin_b0 = on
          delay_1s ( 1 )
          pin_b0 = off
          delay_1s ( 1 )
          end loop
          end if
           
          if pin_a2 == high then
          forever loop
          pin_b0 = on
          delay_1s ( 2 )
          pin_b0 = off
          delay_1s ( 2 )
          end loop
          end if
           
           
          and if i then set pin_a1 to low and pin_2 to high and press the reset button (/MCLR) the program continues as before with out notice !
           
          But if i however turn the power on / off from the pic it does as its supposted to
           
          Is there a way to "Hard reset" the PIC ?
          possibly by connecting the Vcc to a momentary button via a resistor to ground and then make a hard reset ?`?
           
          Thanks for any support
           
          Lasse Madsen
           
           
           
           
           
           
           
           
          M.v.h.
          Lasse Madsen
          Højrupsvej 52, 2.m.f.
          9900 Frederikshavn


          Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


          Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
        • Philip Pemberton
          I don t know if this will help, but try replacing the 4k7 that you connected between VCC and MCLR with a 1k. Might help. -- Phil. http://www.philpem.f9.co.uk/
          Message 4 of 10 , Jun 3, 2001
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            I don't know if this will help, but try replacing the 4k7 that you connected between VCC and MCLR with a 1k. Might help.
             
            ----- Original Message -----
            Sent: Saturday, June 02, 2001 11:08 PM
            Subject: Re: [jallist] overreacting ?

            yes a 4K7
             
            and the chip resets in all other codes than a
             
            forever loop - code
             
            ----- Original Message -----
            Sent: Saturday, June 02, 2001 11:43 PM
            Subject: Re: [jallist] overreacting ?

            Did you put resistor from /MCLR to Vcc?
             
            pozdrav
            -------------------------------------------------
            Branko Karaklajic
            branek@...
            http://solair.eunet.yu/~branek
            ----- Original Message -----
            Sent: Saturday, June 02, 2001 7:52 PM
            Subject: [jallist] overreacting ?

            Hi all
             
            I have 2 questions:
             
            Question 1
             
            Im building a power supply to my project ...
            It draws about 550mA in peaks
             
            I have a 6-0-6 Trafo which i full wave rectify the old ( 2 diode way )
             
            this circuit delivers a voltage of 11,5 volt but will some ripple ofcause
             
            now i have a 7805 ( TO-220 capsule ) wich i connect to the 11,5V
             
            BUT ! here comes my trouble
             
            If i calculate the loss effect of the 7805 its wery high
            11,5 - 5 * 550mA = 3,75 W
             
            I have a small cooling plate wich should treat this problem
            but what about the ripple will this have any effect on the 16F84 ???
             
             
            Question 2
             
            Is it possible to hard reset the pic ?
             
            i have the following jal code:
             
            please note that pin_a1 and pin_a2 are connected to a normal on/off button not a momentary button
             
            if pin_a1 == high then
            forever loop
            pin_b0 = on
            delay_1s ( 1 )
            pin_b0 = off
            delay_1s ( 1 )
            end loop
            end if
             
            if pin_a2 == high then
            forever loop
            pin_b0 = on
            delay_1s ( 2 )
            pin_b0 = off
            delay_1s ( 2 )
            end loop
            end if
             
             
            and if i then set pin_a1 to low and pin_2 to high and press the reset button (/MCLR) the program continues as before with out notice !
             
            But if i however turn the power on / off from the pic it does as its supposted to
             
            Is there a way to "Hard reset" the PIC ?
            possibly by connecting the Vcc to a momentary button via a resistor to ground and then make a hard reset ?`?
             
            Thanks for any support
             
            Lasse Madsen
             
             
             
             
             
             
             
             
            M.v.h.
            Lasse Madsen
            Højrupsvej 52, 2.m.f.
            9900 Frederikshavn


            Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


            Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


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          • Lasse Madsen
            Thanks for the suggestion Phil ! I tried replacing the resistor as you said but i didnt help then i remembered something about pressing and holding the reset
            Message 5 of 10 , Jun 3, 2001
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              Thanks for the suggestion Phil !
               
              I tried replacing the resistor as you said but i didnt help
              then i remembered something about pressing and holding the reset button until the clockpulse from the crystal have appeared 4 times ( or someting like that)
               
              so if i press and hold my reset button for about 4 seconds it works ok ...
              guess i just have to live with this then.
               
              I apoligize for the trouble ...
              But maybe someone else had also forgotton this :o)
               
              Best Regards
              Lasse Madsen
               
               
              ----- Original Message -----
              Sent: Sunday, June 03, 2001 9:22 AM
              Subject: Re: [jallist] overreacting ?

              I don't know if this will help, but try replacing the 4k7 that you connected between VCC and MCLR with a 1k. Might help.
               
              ----- Original Message -----
              Sent: Saturday, June 02, 2001 11:08 PM
              Subject: Re: [jallist] overreacting ?

              yes a 4K7
               
              and the chip resets in all other codes than a
               
              forever loop - code
               
              ----- Original Message -----
              Sent: Saturday, June 02, 2001 11:43 PM
              Subject: Re: [jallist] overreacting ?

              Did you put resistor from /MCLR to Vcc?
               
              pozdrav
              -------------------------------------------------
              Branko Karaklajic
              branek@...
              http://solair.eunet.yu/~branek
              ----- Original Message -----
              Sent: Saturday, June 02, 2001 7:52 PM
              Subject: [jallist] overreacting ?

              Hi all
               
              I have 2 questions:
               
              Question 1
               
              Im building a power supply to my project ...
              It draws about 550mA in peaks
               
              I have a 6-0-6 Trafo which i full wave rectify the old ( 2 diode way )
               
              this circuit delivers a voltage of 11,5 volt but will some ripple ofcause
               
              now i have a 7805 ( TO-220 capsule ) wich i connect to the 11,5V
               
              BUT ! here comes my trouble
               
              If i calculate the loss effect of the 7805 its wery high
              11,5 - 5 * 550mA = 3,75 W
               
              I have a small cooling plate wich should treat this problem
              but what about the ripple will this have any effect on the 16F84 ???
               
               
              Question 2
               
              Is it possible to hard reset the pic ?
               
              i have the following jal code:
               
              please note that pin_a1 and pin_a2 are connected to a normal on/off button not a momentary button
               
              if pin_a1 == high then
              forever loop
              pin_b0 = on
              delay_1s ( 1 )
              pin_b0 = off
              delay_1s ( 1 )
              end loop
              end if
               
              if pin_a2 == high then
              forever loop
              pin_b0 = on
              delay_1s ( 2 )
              pin_b0 = off
              delay_1s ( 2 )
              end loop
              end if
               
               
              and if i then set pin_a1 to low and pin_2 to high and press the reset button (/MCLR) the program continues as before with out notice !
               
              But if i however turn the power on / off from the pic it does as its supposted to
               
              Is there a way to "Hard reset" the PIC ?
              possibly by connecting the Vcc to a momentary button via a resistor to ground and then make a hard reset ?`?
               
              Thanks for any support
               
              Lasse Madsen
               
               
               
               
               
               
               
               
              M.v.h.
              Lasse Madsen
              Højrupsvej 52, 2.m.f.
              9900 Frederikshavn


              Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


              Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


              Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

              ---
              Outgoing mail is certified Virus Free.
              Checked by AVG anti-virus system (http://www.grisoft.com).
              Version: 6.0.255 / Virus Database: 128 - Release Date: 17/05/01


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            • Javi
              Hi Lasse: The 7805 regulator chip in TO220 supports 1W without cooling. I haven t specs now, so I don t know what are the limit with cooling. If TO220 capsule
              Message 6 of 10 , Jun 3, 2001
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                Hi Lasse:

                The 7805 regulator chip in TO220 supports 1W without cooling. I haven't
                specs now, so I don't know what are the limit with cooling. If TO220 capsule
                is insuficient you can use the same chip in a TO3 capsule. Tomorrow Monday
                I'll search for you the max. power ratings for this chip.

                About the second question, the is diferent for the pic your 'hard reset'
                (Power On Reset in Microchip terminology) and the MCLR reset. Some SFR's
                reg.
                can have diferent values depending the source of the reset. See pages 41 to
                47 for the 16F84 and 125 to 130 for the 16F877 on the datasheets.

                Note that in POR and MCLR reset Program Counter is reset anyway. In the
                boot loader that I use in the 16F876, after downloading the program via
                serial I make a MCLR reset to the chip to run my program (and it works).
                Perhaps your problem is a incorret init of the sfr's. Don't supose that all
                the sfr's will hold the previous value.



                Regards, Javi.



                -----Mensaje original-----
                De: Lasse Madsen <Lasse.Madsen@...>
                Para: jallist@yahoogroups.com <jallist@yahoogroups.com>
                Fecha: sábado, 02 de junio de 2001 20:00
                Asunto: [jallist] overreacting ?


                Hi all

                I have 2 questions:

                Question 1

                Im building a power supply to my project ...
                It draws about 550mA in peaks

                I have a 6-0-6 Trafo which i full wave rectify the old ( 2 diode way )

                this circuit delivers a voltage of 11,5 volt but will some ripple ofcause

                now i have a 7805 ( TO-220 capsule ) wich i connect to the 11,5V

                BUT ! here comes my trouble

                If i calculate the loss effect of the 7805 its wery high
                11,5 - 5 * 550mA = 3,75 W

                I have a small cooling plate wich should treat this problem
                but what about the ripple will this have any effect on the 16F84 ???


                Question 2

                Is it possible to hard reset the pic ?

                i have the following jal code:

                please note that pin_a1 and pin_a2 are connected to a normal on/off button
                not a momentary button

                if pin_a1 == high then
                forever loop
                pin_b0 = on
                delay_1s ( 1 )
                pin_b0 = off
                delay_1s ( 1 )
                end loop
                end if

                if pin_a2 == high then
                forever loop
                pin_b0 = on
                delay_1s ( 2 )
                pin_b0 = off
                delay_1s ( 2 )
                end loop
                end if


                and if i then set pin_a1 to low and pin_2 to high and press the reset button
                (/MCLR) the program continues as before with out notice !

                But if i however turn the power on / off from the pic it does as its
                supposted to

                Is there a way to "Hard reset" the PIC ?
                possibly by connecting the Vcc to a momentary button via a resistor to
                ground and then make a hard reset ?`?

                Thanks for any support

                Lasse Madsen








                M.v.h.
                Lasse Madsen
                Højrupsvej 52, 2.m.f.
                9900 Frederikshavn
              • wouter van ooijen & floortje hanneman
                ... Are you sure of the 11.5? 6-0-6 rectified twice-half wave should give (sqrt(2)*6 - 0.6) = 7.8 V peak. drawing 0.5A from let s say 10mF would cause a ripple
                Message 7 of 10 , Jun 3, 2001
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                  > I have a 6-0-6 Trafo which i full wave rectify the old ( 2 diode way )
                  > this circuit delivers a voltage of 11,5 volt but will some ripple ofcause

                  Are you sure of the 11.5? 6-0-6 rectified twice-half wave should give
                  (sqrt(2)*6 - 0.6) = 7.8 V peak. drawing 0.5A from let's say 10mF would cause
                  a ripple of 0.5 V, so the lowest input voltage would be 7.3V. The minimum
                  input of an 7805 is either 7 or 8 V (reading the datasheet quickly I could
                  not find out what it really is). Add the fact that the line voltage can be
                  low (20%?) so your power supply might be too marginal. Did you try running
                  your cicruit from a good lab supply with ample current?

                  And it does not hurt to have
                  - a big cap before the 7805 (calc above assumes 10mF)
                  - 0.1u before the 7805
                  - a smaller big cap after the 7805 (100u)
                  - 0.1u after the 7805
                  - 0.1u very close to the PIC
                  - a larger cap near the PIC when it (or something else near it) draws
                  substantial current (10..1000uF)
                  you can always leave out lateron truns out to be not really needed...

                  I always use a 33k MCLR pullup which has never caused me trouble. I use my
                  in-circuit programmer which cannot drive the MCLR with a lower value
                  resistor.

                  Wouter
                • Lasse Madsen
                  Thanks Javi I ll go for the TO-220 capsule with a little larger cooling plate because a TO-3 wont fit my project ( size wise ) and I ll lower the input voltage
                  Message 8 of 10 , Jun 3, 2001
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                    Thanks Javi

                    I'll go for the TO-220 capsule with a little larger cooling plate because a
                    TO-3 wont fit my project ( size wise ) and I'll lower the input voltage on
                    the 7805 to ensure minimal power loss.

                    Thanks for your noticification on the datasheet pages !

                    I dont think that theres any need for you to find the specefications on the
                    7805 as it should work better when i lower the voltage in and uses a bigger
                    cooling plate.

                    Best regads and many thanks
                    Lasse Madsen




                    ----- Original Message -----
                    From: "Javi" <JAPUS11@...>
                    To: <jallist@yahoogroups.com>
                    Sent: Sunday, June 03, 2001 5:20 PM
                    Subject: RE: [jallist] overreacting ?


                    > Hi Lasse:
                    >
                    > The 7805 regulator chip in TO220 supports 1W without cooling. I
                    haven't
                    > specs now, so I don't know what are the limit with cooling. If TO220
                    capsule
                    > is insuficient you can use the same chip in a TO3 capsule. Tomorrow Monday
                    > I'll search for you the max. power ratings for this chip.
                    >
                    > About the second question, the is diferent for the pic your 'hard
                    reset'
                    > (Power On Reset in Microchip terminology) and the MCLR reset. Some SFR's
                    > reg.
                    > can have diferent values depending the source of the reset. See pages 41
                    to
                    > 47 for the 16F84 and 125 to 130 for the 16F877 on the datasheets.
                    >
                    > Note that in POR and MCLR reset Program Counter is reset anyway. In
                    the
                    > boot loader that I use in the 16F876, after downloading the program via
                    > serial I make a MCLR reset to the chip to run my program (and it works).
                    > Perhaps your problem is a incorret init of the sfr's. Don't supose that
                    all
                    > the sfr's will hold the previous value.
                    >
                    >
                    >
                    > Regards, Javi.
                    >
                    >
                    >
                    > -----Mensaje original-----
                    > De: Lasse Madsen <Lasse.Madsen@...>
                    > Para: jallist@yahoogroups.com <jallist@yahoogroups.com>
                    > Fecha: sábado, 02 de junio de 2001 20:00
                    > Asunto: [jallist] overreacting ?
                    >
                    >
                    > Hi all
                    >
                    > I have 2 questions:
                    >
                    > Question 1
                    >
                    > Im building a power supply to my project ...
                    > It draws about 550mA in peaks
                    >
                    > I have a 6-0-6 Trafo which i full wave rectify the old ( 2 diode way )
                    >
                    > this circuit delivers a voltage of 11,5 volt but will some ripple ofcause
                    >
                    > now i have a 7805 ( TO-220 capsule ) wich i connect to the 11,5V
                    >
                    > BUT ! here comes my trouble
                    >
                    > If i calculate the loss effect of the 7805 its wery high
                    > 11,5 - 5 * 550mA = 3,75 W
                    >
                    > I have a small cooling plate wich should treat this problem
                    > but what about the ripple will this have any effect on the 16F84 ???
                    >
                    >
                    > Question 2
                    >
                    > Is it possible to hard reset the pic ?
                    >
                    > i have the following jal code:
                    >
                    > please note that pin_a1 and pin_a2 are connected to a normal on/off button
                    > not a momentary button
                    >
                    > if pin_a1 == high then
                    > forever loop
                    > pin_b0 = on
                    > delay_1s ( 1 )
                    > pin_b0 = off
                    > delay_1s ( 1 )
                    > end loop
                    > end if
                    >
                    > if pin_a2 == high then
                    > forever loop
                    > pin_b0 = on
                    > delay_1s ( 2 )
                    > pin_b0 = off
                    > delay_1s ( 2 )
                    > end loop
                    > end if
                    >
                    >
                    > and if i then set pin_a1 to low and pin_2 to high and press the reset
                    button
                    > (/MCLR) the program continues as before with out notice !
                    >
                    > But if i however turn the power on / off from the pic it does as its
                    > supposted to
                    >
                    > Is there a way to "Hard reset" the PIC ?
                    > possibly by connecting the Vcc to a momentary button via a resistor to
                    > ground and then make a hard reset ?`?
                    >
                    > Thanks for any support
                    >
                    > Lasse Madsen
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    > M.v.h.
                    > Lasse Madsen
                    > Højrupsvej 52, 2.m.f.
                    > 9900 Frederikshavn
                    >
                    >
                    >
                    >
                    >
                    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                    >
                    >
                    >
                    >
                  • Vasile Surducan
                    ... On my medical equipment I had serious problem with this 7805.According to datasheet you need at least minim 9V dc input voltage when the suplly have
                    Message 9 of 10 , Jun 4, 2001
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                      On Sun, 3 Jun 2001, wouter van ooijen & floortje hanneman wrote:

                      > a ripple of 0.5 V, so the lowest input voltage would be 7.3V. The minimum
                      > input of an 7805 is either 7 or 8 V (reading the datasheet quickly I could

                      On my medical equipment I had serious problem with this 7805.According to
                      datasheet you need at least minim 9V dc input voltage when the suplly have
                      minimum voltage ( ie. 220V -15% = 198V )
                      A best option is to use low dropout 5V three terminal supply ( LM series)
                      Vasile
                    • Philip Pemberton
                      A few more ideas for you. How about: A 4-bit binary counter set to reset when the most significant output (Q3) goes high, clocked using the PIC s CLKIN pin. A
                      Message 10 of 10 , Jun 4, 2001
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                        A few more ideas for you. How about:
                            A 4-bit binary counter set to reset when the most significant output (Q3) goes high, clocked using the PIC's CLKIN pin.
                            A Dallas Semiconductor EconoReset (much smaller and a hell of a lot cheaper).
                         
                        BTW, you shouldn't need to wait four seconds. Try waiting around one second and then wait less each time until you find out how long it takes to reliably reset the PIC. OTOH, a Dallas EconoReset will be a lot easier to use (connect it to Vcc, Gnd and /MCLR, then hook a normally open pushbutton switch between the EconoReset's RST OUT pin and ground).
                         
                        I have used EconoResets before - they are available in various speed and voltage specs, as well as different package types (TO92 seems to be the most popular, but surface-mount variants are available). I actually used one to reset a 6502 CPU. Chances are, an EconoReset will work perfectly when used to reset a PIC.
                         
                        HTH.
                         
                        ----- Original Message -----
                        Sent: Sunday, June 03, 2001 2:34 PM
                        Subject: Re: [jallist] overreacting ?

                        Thanks for the suggestion Phil !
                         
                        I tried replacing the resistor as you said but i didnt help
                        then i remembered something about pressing and holding the reset button until the clockpulse from the crystal have appeared 4 times ( or someting like that)
                         
                        so if i press and hold my reset button for about 4 seconds it works ok ...
                        guess i just have to live with this then.
                         
                        I apoligize for the trouble ...
                        But maybe someone else had also forgotton this :o)
                         
                        Best Regards
                        Lasse Madsen
                         
                         
                        ----- Original Message -----
                        Sent: Sunday, June 03, 2001 9:22 AM
                        Subject: Re: [jallist] overreacting ?

                        I don't know if this will help, but try replacing the 4k7 that you connected between VCC and MCLR with a 1k. Might help.
                         
                        ----- Original Message -----
                        Sent: Saturday, June 02, 2001 11:08 PM
                        Subject: Re: [jallist] overreacting ?

                        yes a 4K7
                         
                        and the chip resets in all other codes than a
                         
                        forever loop - code
                         
                        ----- Original Message -----
                        Sent: Saturday, June 02, 2001 11:43 PM
                        Subject: Re: [jallist] overreacting ?

                        Did you put resistor from /MCLR to Vcc?
                         
                        pozdrav
                        -------------------------------------------------
                        Branko Karaklajic
                        branek@...
                        http://solair.eunet.yu/~branek
                        ----- Original Message -----
                        Sent: Saturday, June 02, 2001 7:52 PM
                        Subject: [jallist] overreacting ?

                        Hi all
                         
                        I have 2 questions:
                         
                        Question 1
                         
                        Im building a power supply to my project ...
                        It draws about 550mA in peaks
                         
                        I have a 6-0-6 Trafo which i full wave rectify the old ( 2 diode way )
                         
                        this circuit delivers a voltage of 11,5 volt but will some ripple ofcause
                         
                        now i have a 7805 ( TO-220 capsule ) wich i connect to the 11,5V
                         
                        BUT ! here comes my trouble
                         
                        If i calculate the loss effect of the 7805 its wery high
                        11,5 - 5 * 550mA = 3,75 W
                         
                        I have a small cooling plate wich should treat this problem
                        but what about the ripple will this have any effect on the 16F84 ???
                         
                         
                        Question 2
                         
                        Is it possible to hard reset the pic ?
                         
                        i have the following jal code:
                         
                        please note that pin_a1 and pin_a2 are connected to a normal on/off button not a momentary button
                         
                        if pin_a1 == high then
                        forever loop
                        pin_b0 = on
                        delay_1s ( 1 )
                        pin_b0 = off
                        delay_1s ( 1 )
                        end loop
                        end if
                         
                        if pin_a2 == high then
                        forever loop
                        pin_b0 = on
                        delay_1s ( 2 )
                        pin_b0 = off
                        delay_1s ( 2 )
                        end loop
                        end if
                         
                         
                        and if i then set pin_a1 to low and pin_2 to high and press the reset button (/MCLR) the program continues as before with out notice !
                         
                        But if i however turn the power on / off from the pic it does as its supposted to
                         
                        Is there a way to "Hard reset" the PIC ?
                        possibly by connecting the Vcc to a momentary button via a resistor to ground and then make a hard reset ?`?
                         
                        Thanks for any support
                         
                        Lasse Madsen
                         
                         
                         
                         
                         
                         
                         
                         
                        M.v.h.
                        Lasse Madsen
                        Højrupsvej 52, 2.m.f.
                        9900 Frederikshavn


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