nickos47403
New Member
Hello all:
I just recently built my own p16pro40 programmer. I had built it once last summer (and it worked then), but when I tried it again a couple of weeks ago, the thing had quit working.
I have rebuilt it multiple times. I can hook it up to my desktop computer and set the correct pins high/low using Winpicprog and Winpic. The correct LEDs light up, and I checked the voltages coming from the parallel port (3.35 volts high and .09 volts low). I also checked the voltage going to the PIC during programming; it is 12.82 volts. Is that high enough?
I have tried programming a couple of 16f628a's as well as a 16f877a. The programmer/software seems to read the PIC with no problem. When I try to write to it, though, it reads back a blank PIC. That's why I ask about the voltage being high enough, because I know that is one reason why it might not program correctly. I have tried all of the suggestions on other boards referring to the the p16pro40 (adding 10k resistor to the PGM port, removing the optional resistor and capacitor shown in the schematic, powering it using two 9V batteries instead of a wall wart, running the software in Windows 98 instead of XP).
Can anyone think of another reason why it might not be successfully writing to the PIC? Thanks a lot for your help.
I just recently built my own p16pro40 programmer. I had built it once last summer (and it worked then), but when I tried it again a couple of weeks ago, the thing had quit working.
I have rebuilt it multiple times. I can hook it up to my desktop computer and set the correct pins high/low using Winpicprog and Winpic. The correct LEDs light up, and I checked the voltages coming from the parallel port (3.35 volts high and .09 volts low). I also checked the voltage going to the PIC during programming; it is 12.82 volts. Is that high enough?
I have tried programming a couple of 16f628a's as well as a 16f877a. The programmer/software seems to read the PIC with no problem. When I try to write to it, though, it reads back a blank PIC. That's why I ask about the voltage being high enough, because I know that is one reason why it might not program correctly. I have tried all of the suggestions on other boards referring to the the p16pro40 (adding 10k resistor to the PGM port, removing the optional resistor and capacitor shown in the schematic, powering it using two 9V batteries instead of a wall wart, running the software in Windows 98 instead of XP).
Can anyone think of another reason why it might not be successfully writing to the PIC? Thanks a lot for your help.