Mosaic
Well-Known Member
This probably applies to many µC programmers (ICSP).
1) The Vss is grounded to the PC chassis via the USB. I suppose for EMI reasons.
https://electrosome.com/pickit2/
I happened to be testing an isolated circuit with a scope...once, after reprogramming the µC I forgot to remove the ICSP plug which is ok most of the time EXCEPT when there is another ground making a loop. That happened to be my scope probe ground clip. As I powered on, I got a powered ground loop from the probe clip thru the scope into the UPS, back into the PC, thru the USB, thru the pickit2 ..into the ICSP header on the PCB and into the circuit ground...burning out 3 IC's and several traces , costing me a day of repairs!
I am wondering if I can remove that chassis ground from the Pickit2 to prevent such accidents.
1) The Vss is grounded to the PC chassis via the USB. I suppose for EMI reasons.
https://electrosome.com/pickit2/
I happened to be testing an isolated circuit with a scope...once, after reprogramming the µC I forgot to remove the ICSP plug which is ok most of the time EXCEPT when there is another ground making a loop. That happened to be my scope probe ground clip. As I powered on, I got a powered ground loop from the probe clip thru the scope into the UPS, back into the PC, thru the USB, thru the pickit2 ..into the ICSP header on the PCB and into the circuit ground...burning out 3 IC's and several traces , costing me a day of repairs!
I am wondering if I can remove that chassis ground from the Pickit2 to prevent such accidents.