Hi Folks,

Here is an interesting PIC lesson I just learned the hard way.

I am developing  new programmer firmware and using a 16C64 chip.
 Because the PCB  is only  single-sided, I only connected one of the
two VDDs to save headaches with the track layout.

Everything seemed ok  until I tried  to program 5x parts.

All of a sudden it would crash most times a "000" was to be programmed.

After stuffing around adding caps here and there, swapping chips,
regulators, and resorting to a fair array of unrepeatable verbal
incantations, I finally decided to connect the "other" VDD and voila! it
worked 100%

Ok, so I've learnt my lesson, don't cut corners with the PICs power rails.

So, if like me, you are tempted to only connect one VDD or GND, perhaps
this cautionary tale may help change your mind.

Jim



--------------------------------------------------------
Jim Robertson
Email: newfound@pipeline.com.au

http://www.pipeline.com.au/users/newfound
--------------------------------------------------------