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Connecting external power to PIC16F877A

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Shipton

New Member
Okay, so I have a Junebug that's using the ICD to program a target PIC16.

It read and verified it okay after jumping the +5V and U5V pins together, but when I try to program, I get:

PK2Error0024: PICkit 2 was unable to establish a valid VDD on the target (Attempted V - Read V)
Description: PICkit 2 was unable to provide the intended VDD voltage to the target. This is usually caused by a heavy VDD load. Suggested Actions: Power the target board externally, and/or try calibrating the PICkit 2 unit with the PICkit 2 Programmer software.

So I take it my easiest route is supplying +5V directly to VDD.

This is my question: do I leave VDD connected to the Junebug, or do I sever that connection and use ONLY the external power?

i.e. should both my separate 5V source and the Junebug be on VDD at the same time?

What about GND to VSS?

Thanks!
 

Gayan Soyza

Active Member
PICKIT2 (junebug) takes power from the USB port.But for the target board you need to power a separate 5V supply if you having any VDD level errors.

You must give 5V to the VDD & VSS pins in the ICSP connector.

I also powering externally.
 
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AllVol

New Member
Can anyone help please!?

You shouldn't be having trouble with the 877. It should adapt nicely to the PICkit 2/Junebug.

Make sure VCC is to pin 32, with GND to 31. The PK2's clock line goes to pin 39, while pin 40 gets the data line. !MCLR goes to pin 1.

I have a 16F876A, which is the 28 pin version. Mine works fine with just an RC external osc.
 

Shipton

New Member
PICKIT2 (junebug) takes power from the USB port.But for the target board you need to power a separate 5V supply if you having any VDD level errors.

You must give 5V to the VDD & VSS pins in the ICSP connector.

I also powering externally.

Do you have a picture or diagram by any chance?

I'm just using a 7805 to provide the 5V. And 5V to both VDD -AND- VSS?
 
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