Help! sinking fast!

[paul borgmeier]

It programmed one time as normal and that was it. Now it's erroring out with the same crap and will not program.

Have you tried erasing the PIC before RE-programming it? ... just a thought and maybe just a straw (that is what I have to do with my PS+ programmer)

[fowardbias]

No help with the erase idea. Just guessing at this time but I think the programming voltages or timing sequences are off or intermittent. I am using the 16F628 chip. Aftering doing a verify and a program things look normal regarding the red LED, but no code is entered. Also the red LED never comes on anymore like it used to when first powered up with computer is off. When the computer is turned on the LED would go off, not anymore. Hardware/software? Don't know yet, time limited with the hoilday going on.

[skimask]

I am using the 16F628 chip.

And another straw...
PIC16F628 or PIC16F628A?

[fowardbias]

It's a 16F628 and I think it's OK. (unless the lot was trash) I have shorted the base/emitter junction of the 2N3906 driver transistor for the LED and it comes on every time. I'll check the gating for the 7407 tomorrow, and if good start running the parallel pin outputs with a scope. Since all the signals have to come out at set times and with defined voltage levels it will be difficult to say that they are good not knowing the programming algorithm. I am getting too side tracked with this considering knowledge and equipment. The supply voltages are OK and it looks like if it's a hardware issue it will be the laptop. I will install the software into the work station tomorrow and compare. Later I'm out of here.