Hi saranga2000!saranga2000 wrote:Hi Holden,
I tried without the led's. Previously I also had not connected capacitors across the power supply, I did that this time around.
Running sudo ./rpp still returns the same Error: unknown device or programmer not connected.
I once again connected led's to each of the outs, to check that they could be lit up by high/low of pins 4, 7, 9. Once I was sure these were working, I removed them like you had advised.
I am stumped, can you please help? How would I go about debugging this? Could the pic be faulty ( it is brand new)? Is there anything I'm missing? Is there any way to monitor the pulse profile ( the kind that you simulated on ngspice) when I run sudo rpp? Would that help?
I can confirm, that Holdens circuit works ok - I have build it last week and have tested it with two chips. So there must be a problem somewhere in your construction or Raspberry GPIO. Can you measure, that there is really 5V DC at the output of the 78L05? And that this +5V is at the pin 14 of the 16F628 chip (and ground at the pin 5 of the 16F628 chip)? And that your power source is able to deliver 12-14V DC for VPP?
As for Raspberry GPIO independent test I can recomend wiringPi gpio project. You can verify I/O state easily using wiringPi gpio utility - and read/set gpio pin levels.
And the best way to test if your chip is ok is to use it in another programmer - if you have any nearby.