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"JDM" pic programmer 2
Is anybody using the JDM serial pic programmer?
I built the Pic-Programmer 2 version and I'm debugging it before pluging in a live pic. (www.jdm.homepage.dk/newpics.htm) It seems that the VPP (MCLR) pin goes from -.6v to +12.87 volts. I'm worried that the negative voltage (when it should be zero) might damage the device being programmed. I tried adding a 1n4148 clamp diode from MCLR to VSS (Anode to VSS) and that brings the 'zero' voltage down to -.37v or so. VDD runs +5.11v (exactly what the Zener diode is rated at). The +12.87v for vpp is about what it should be given the 8.2v and 5.1v zeners plus the drop through Q1 (and that 8.2v zener might be the low side, I didn't measure the drop across it). If the slightly negative voltage on MCLR isn't fatal, I guess the programmer is good to go. Any ideas? |
"Ken Scharf" wrote in message
... Is anybody using the JDM serial pic programmer? I built the Pic-Programmer 2 version and I'm debugging it before pluging in a live pic. (www.jdm.homepage.dk/newpics.htm) I've used it - it works OK on Win98 but is very unreliable with WinXP, even with the XP drivers. Leon -- Leon Heller, G1HSM http://www.geocities.com/leon_heller |
"Ken Scharf" wrote in message
... Is anybody using the JDM serial pic programmer? I built the Pic-Programmer 2 version and I'm debugging it before pluging in a live pic. (www.jdm.homepage.dk/newpics.htm) I've used it - it works OK on Win98 but is very unreliable with WinXP, even with the XP drivers. Leon -- Leon Heller, G1HSM http://www.geocities.com/leon_heller |
Leon Heller wrote:
"Ken Scharf" wrote in message ... Is anybody using the JDM serial pic programmer? I built the Pic-Programmer 2 version and I'm debugging it before pluging in a live pic. (www.jdm.homepage.dk/newpics.htm) I've used it - it works OK on Win98 but is very unreliable with WinXP, even with the XP drivers. Leon I'm going to use it on Linux with PikDev. |
Leon Heller wrote:
"Ken Scharf" wrote in message ... Is anybody using the JDM serial pic programmer? I built the Pic-Programmer 2 version and I'm debugging it before pluging in a live pic. (www.jdm.homepage.dk/newpics.htm) I've used it - it works OK on Win98 but is very unreliable with WinXP, even with the XP drivers. Leon I'm going to use it on Linux with PikDev. |
On Sun, 13 Jun 2004 09:42:05 -0400, Ken Scharf hath writ:
Leon Heller wrote: "Ken Scharf" wrote in message ... Is anybody using the JDM serial pic programmer? I built the Pic-Programmer 2 version and I'm debugging it before pluging in a live pic. (www.jdm.homepage.dk/newpics.htm) I've used it - it works OK on Win98 but is very unreliable with WinXP, even with the XP drivers. I'm going to use it on Linux with PikDev. Good for you, fella! Jonesy -- | Marvin L Jones | jonz | W3DHJ | linux | Gunnison, Colorado | @ | Jonesy | O/S2 __ | 7,703' -- 2,345m | frontier.net | DM68mn SK |
On Sun, 13 Jun 2004 09:42:05 -0400, Ken Scharf hath writ:
Leon Heller wrote: "Ken Scharf" wrote in message ... Is anybody using the JDM serial pic programmer? I built the Pic-Programmer 2 version and I'm debugging it before pluging in a live pic. (www.jdm.homepage.dk/newpics.htm) I've used it - it works OK on Win98 but is very unreliable with WinXP, even with the XP drivers. I'm going to use it on Linux with PikDev. Good for you, fella! Jonesy -- | Marvin L Jones | jonz | W3DHJ | linux | Gunnison, Colorado | @ | Jonesy | O/S2 __ | 7,703' -- 2,345m | frontier.net | DM68mn SK |
"Ken Scharf" wrote in message
... diode from MCLR to VSS (Anode to VSS) and that brings the 'zero' voltage down to -.37v or so. You may want to check the datasheet for the specific part you are going to use. the 16F628 datasheet, for example, specifies the absolute minimum voltage on MCLR at -0.3v. Ditto with the 877 and 84A. ... |
"Ken Scharf" wrote in message
... diode from MCLR to VSS (Anode to VSS) and that brings the 'zero' voltage down to -.37v or so. You may want to check the datasheet for the specific part you are going to use. the 16F628 datasheet, for example, specifies the absolute minimum voltage on MCLR at -0.3v. Ditto with the 877 and 84A. ... |
xpyttl wrote:
"Ken Scharf" wrote in message ... diode from MCLR to VSS (Anode to VSS) and that brings the 'zero' voltage down to -.37v or so. You may want to check the datasheet for the specific part you are going to use. the 16F628 datasheet, for example, specifies the absolute minimum voltage on MCLR at -0.3v. Ditto with the 877 and 84A. .. I could put a germainium or low voltage drop si in series with the VPP to block the negative voltage all together. That would somewhat limit the vpp, which might be a problem. |
xpyttl wrote:
"Ken Scharf" wrote in message ... diode from MCLR to VSS (Anode to VSS) and that brings the 'zero' voltage down to -.37v or so. You may want to check the datasheet for the specific part you are going to use. the 16F628 datasheet, for example, specifies the absolute minimum voltage on MCLR at -0.3v. Ditto with the 877 and 84A. .. I could put a germainium or low voltage drop si in series with the VPP to block the negative voltage all together. That would somewhat limit the vpp, which might be a problem. |
xpyttl wrote:
"Ken Scharf" wrote in message ... diode from MCLR to VSS (Anode to VSS) and that brings the 'zero' voltage down to -.37v or so. You may want to check the datasheet for the specific part you are going to use. the 16F628 datasheet, for example, specifies the absolute minimum voltage on MCLR at -0.3v. Ditto with the 877 and 84A. .. I added a diode in series with the VPP output from the emitter or Q1 (with the anode toward Q1's emitter) and a second shut diode from the MCLR pin to VSS (anode toward VSS). Now the VPP voltage at MCLR swings from -0.05v to +12.6 volts. I hope that's enough VPP. I may have to change out the 8.2v zener, I measured the voltage across it and it appears on the low side. I could also just connect a 1n4001 or two in series with it to raise the vpp supply. Anyway seems the programmer is safe now. Still need to put a scope to the PGC and PGD lines and check they are in spec. |
xpyttl wrote:
"Ken Scharf" wrote in message ... diode from MCLR to VSS (Anode to VSS) and that brings the 'zero' voltage down to -.37v or so. You may want to check the datasheet for the specific part you are going to use. the 16F628 datasheet, for example, specifies the absolute minimum voltage on MCLR at -0.3v. Ditto with the 877 and 84A. .. I added a diode in series with the VPP output from the emitter or Q1 (with the anode toward Q1's emitter) and a second shut diode from the MCLR pin to VSS (anode toward VSS). Now the VPP voltage at MCLR swings from -0.05v to +12.6 volts. I hope that's enough VPP. I may have to change out the 8.2v zener, I measured the voltage across it and it appears on the low side. I could also just connect a 1n4001 or two in series with it to raise the vpp supply. Anyway seems the programmer is safe now. Still need to put a scope to the PGC and PGD lines and check they are in spec. |
"Ken Scharf" wrote in message
. .. I could put a germainium or low voltage drop si in series with the VPP to block the negative voltage all together. That would somewhat limit the vpp, which might be a problem. I don't know definitively what you need here. A lot of older programmers went through all sorts of hoops to be sure that value was above 12 volts. However, lots and lots of folks have success with around 9 or so. I haven't been able to find a spec, other than the maximum, but Microchip generally refers to this as "13 volts". ... ... |
"Ken Scharf" wrote in message
. .. I could put a germainium or low voltage drop si in series with the VPP to block the negative voltage all together. That would somewhat limit the vpp, which might be a problem. I don't know definitively what you need here. A lot of older programmers went through all sorts of hoops to be sure that value was above 12 volts. However, lots and lots of folks have success with around 9 or so. I haven't been able to find a spec, other than the maximum, but Microchip generally refers to this as "13 volts". ... ... |
xpyttl wrote:
"Ken Scharf" wrote in message . .. I could put a germainium or low voltage drop si in series with the VPP to block the negative voltage all together. That would somewhat limit the vpp, which might be a problem. I don't know definitively what you need here. A lot of older programmers went through all sorts of hoops to be sure that value was above 12 volts. However, lots and lots of folks have success with around 9 or so. I haven't been able to find a spec, other than the maximum, but Microchip generally refers to this as "13 volts". .. .. I do remember reading that some pics failed to program if vpp wasn't high enough. If 13v is the maximum than I must be close enough with 12.6v! BTW My programmer has a 40 pin socket wired to accept 8,14 and 18 pin pics in the bottom part of the socket (Device pin 1 9 pins up from the bottom in all cases) and 28 pin pics in the upper part of the socket (Device pin 1 at the top of the socket). I have a jumper to remove vpp from pin 15, and one to set pin 12 at vss for 40 pin pics and vdd for all others. So in theory this unit will work with almost all pics. For the 20 pin units I would need to put a socket into the socket so pins 10 and 11 can 'hang ten'. |
xpyttl wrote:
"Ken Scharf" wrote in message . .. I could put a germainium or low voltage drop si in series with the VPP to block the negative voltage all together. That would somewhat limit the vpp, which might be a problem. I don't know definitively what you need here. A lot of older programmers went through all sorts of hoops to be sure that value was above 12 volts. However, lots and lots of folks have success with around 9 or so. I haven't been able to find a spec, other than the maximum, but Microchip generally refers to this as "13 volts". .. .. I do remember reading that some pics failed to program if vpp wasn't high enough. If 13v is the maximum than I must be close enough with 12.6v! BTW My programmer has a 40 pin socket wired to accept 8,14 and 18 pin pics in the bottom part of the socket (Device pin 1 9 pins up from the bottom in all cases) and 28 pin pics in the upper part of the socket (Device pin 1 at the top of the socket). I have a jumper to remove vpp from pin 15, and one to set pin 12 at vss for 40 pin pics and vdd for all others. So in theory this unit will work with almost all pics. For the 20 pin units I would need to put a socket into the socket so pins 10 and 11 can 'hang ten'. |
On Sun, 13 Jun 2004 21:45:46 -0400, "xpyttl"
wrote: "Ken Scharf" wrote in message ... I could put a germainium or low voltage drop si in series with the VPP to block the negative voltage all together. That would somewhat limit the vpp, which might be a problem. I don't know definitively what you need here. A lot of older programmers went through all sorts of hoops to be sure that value was above 12 volts. However, lots and lots of folks have success with around 9 or so. I haven't been able to find a spec, other than the maximum, but Microchip generally refers to this as "13 volts". Perhaps a visit to the PICLIST mailing list will be beneficial |
On Sun, 13 Jun 2004 21:45:46 -0400, "xpyttl"
wrote: "Ken Scharf" wrote in message ... I could put a germainium or low voltage drop si in series with the VPP to block the negative voltage all together. That would somewhat limit the vpp, which might be a problem. I don't know definitively what you need here. A lot of older programmers went through all sorts of hoops to be sure that value was above 12 volts. However, lots and lots of folks have success with around 9 or so. I haven't been able to find a spec, other than the maximum, but Microchip generally refers to this as "13 volts". Perhaps a visit to the PICLIST mailing list will be beneficial |
Ken Scharf wrote:
I'm going to use it on Linux with PikDev. I use Jaakko Hyvatti's version of the JDM84 with picprog software. It works very well on Linux. http://www.iki.fi/hyvatti/ 73, Ed. EI9GQ. -- Remove 'X' to reply by E-mail. Linux 2.6.5 |
Ken Scharf wrote:
I'm going to use it on Linux with PikDev. I use Jaakko Hyvatti's version of the JDM84 with picprog software. It works very well on Linux. http://www.iki.fi/hyvatti/ 73, Ed. EI9GQ. -- Remove 'X' to reply by E-mail. Linux 2.6.5 |
Ken Scharf wrote:
I added a diode in series with the VPP output from the emitter or Q1 (with the anode toward Q1's emitter) and a second shut diode from the MCLR pin to VSS (anode toward VSS). Now the VPP voltage at MCLR swings from -0.05v to +12.6 volts. I hope that's enough VPP. I may have to change out the 8.2v zener, I measured the voltage across it and it appears on the low side. I could also just connect a 1n4001 or two in series with it to raise the vpp supply. Anyway seems the programmer is safe now. Still need to put a scope to the PGC and PGD lines and check they are in spec. When I modified my PicStart Plus Microchip specified the voltage should be 12.75-13.25. Microchip had a mod to lower the voltage from nominal 13.75 to nominal 13.0 for the newer chips (new about 7 years ago). |
Ken Scharf wrote:
I added a diode in series with the VPP output from the emitter or Q1 (with the anode toward Q1's emitter) and a second shut diode from the MCLR pin to VSS (anode toward VSS). Now the VPP voltage at MCLR swings from -0.05v to +12.6 volts. I hope that's enough VPP. I may have to change out the 8.2v zener, I measured the voltage across it and it appears on the low side. I could also just connect a 1n4001 or two in series with it to raise the vpp supply. Anyway seems the programmer is safe now. Still need to put a scope to the PGC and PGD lines and check they are in spec. When I modified my PicStart Plus Microchip specified the voltage should be 12.75-13.25. Microchip had a mod to lower the voltage from nominal 13.75 to nominal 13.0 for the newer chips (new about 7 years ago). |
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