Hi All,
I am having a strange problem with a homebuilt PickIt2. It is wired just as MicroChip designed it, but I substituted a few parts to facilitate thru hole construction. I subbed a BS250P P channel MOSFET for the IRLML6402 and the Q2 part of U5, and a TN0702N3 for the Q1 part of U5. I also subbed a MCP6041 op amp for the MCP6001 op amp. The board is recognized by the PickIt2 v2.61 software. The problems are as follows:
1) When first plugged I get the error message bo that says "Pickit 2 VDD voltage level error. Check target and retry operation." I get this error message whether a PIC is connected or not.
2) When I hit OK the PickIt 2 Programmer software runs and shows that a PickIt 2 was found and connected. Sometimes it finds a connected device, other times it doesn't.
3) If it finds a device, pressing Erase or Blank Check brings up the VDD error box again, and then the software reports "No device detected".
When I run the troubleshooter, the following occurs:
Step 1 passes but I always have about .2V difference between what I set and what I read in the results bo and on my DMM.
Step 2 Pressing "Test VPP" the first time gives me a "Test Failed: VDD Short Detected" error. I can see with my scope that the level is high, and I can measure around +12V with the DMM. If I press "Test VPP" a second time it reports that the test passed with a voltage reading close to what I get on my DMM. When I press "/MCLR On" the VPP level drops to 0.
Step 3 I can control the PGC and PGD lines during step 3 testing.
I feel that Step 2 is the main problem, but tracing my connections has shown no miswires. Plus if there was a miswire, just running the step a second timee would not pass the test.
Did one of my substitutions break something?
Any ideas on how to get this working would be greatly appreciated.
Thanks for reading!
Regards,
Mike
I am having a strange problem with a homebuilt PickIt2. It is wired just as MicroChip designed it, but I substituted a few parts to facilitate thru hole construction. I subbed a BS250P P channel MOSFET for the IRLML6402 and the Q2 part of U5, and a TN0702N3 for the Q1 part of U5. I also subbed a MCP6041 op amp for the MCP6001 op amp. The board is recognized by the PickIt2 v2.61 software. The problems are as follows:
1) When first plugged I get the error message bo that says "Pickit 2 VDD voltage level error. Check target and retry operation." I get this error message whether a PIC is connected or not.
2) When I hit OK the PickIt 2 Programmer software runs and shows that a PickIt 2 was found and connected. Sometimes it finds a connected device, other times it doesn't.
3) If it finds a device, pressing Erase or Blank Check brings up the VDD error box again, and then the software reports "No device detected".
When I run the troubleshooter, the following occurs:
Step 1 passes but I always have about .2V difference between what I set and what I read in the results bo and on my DMM.
Step 2 Pressing "Test VPP" the first time gives me a "Test Failed: VDD Short Detected" error. I can see with my scope that the level is high, and I can measure around +12V with the DMM. If I press "Test VPP" a second time it reports that the test passed with a voltage reading close to what I get on my DMM. When I press "/MCLR On" the VPP level drops to 0.
Step 3 I can control the PGC and PGD lines during step 3 testing.
I feel that Step 2 is the main problem, but tracing my connections has shown no miswires. Plus if there was a miswire, just running the step a second timee would not pass the test.
Did one of my substitutions break something?
Any ideas on how to get this working would be greatly appreciated.
Thanks for reading!
Regards,
Mike