[Usbpicprog-technical] Raspberry Pi PIC Programmer Help?

[Will M. <wm-...@sw...>]

Hi All,

I'm attempting to use the GPIO pins on the Raspberry Pi to program a 
PIC24FJ32GB004, and struggling.

I've had some success, but I can only clock out 0's from the Visi 
register (see note below).

I am hoping that someone on here may be interested in my goal enough to 
lend me their knowledge and perhaps try running the code on their Pi to 
program a chip?

Any comments on what may be wrong or ways to test further would be 
appreciated!

The code is very basic and hacked together, it's C++ and easy enough to 
read.  I've compared with the usbpicprog code and I can't see any 
noticeable differences.

I'll post more details if there's anyone interested.

Thanks,

Will McElderry.

NB: I *believe* I am clocking out zeros from the register as PGD seems 
to accept current when the PIC should be transmitting data - indicating 
the PIC is intentionally holding the ping low.
This was a fortuitous discovery thanks to only having access to an 
oscilloscope with one channel, and using a r/2r ladder to allow 
monitoring 3 pins at the same time. When PGD is not connected to either 
zero or one the output voltage on the channel changes noticeably, a 
state I have been able to induce intentionally by sending invalid 
commands to the PIC, or not requesting clocking out of the Visi 
register, but asking the Pi to try and read from the PGD pin.