In Circuit Programming using PICSTART Plus

arrow · Joined: 17 May 2005 Posts: 213

Hi

I would like to do in circuit programming of a PIC18F2550 using the PICSTART Plus programmer.

I have a diode on the MCLR pin, and I can connect to the PGD and PGC pins, as well as the Vdd and Vss pins.

I use clips to go from the board to the PICSTART plus on these 5 lines (I have wires stickign out of the sockets).

My code is protected.

This does not seem to work. Can someone please tell me how to do this in circuit programming using the PICSTART Plus?

Thank you
a.

jfk1965 · Joined: 21 Oct 2003 Posts: 58

One thing to be careful of is the current drain on the VDD line. You may find your circuit draws more current than the programmer can supply.

I have come across this problem before and isolating the VDD from the rest of the circuit solved it.

arrow · Joined: 17 May 2005 Posts: 213

Hi JFK1965

How can I isolate my Vdd line in circuit?
(Its already on a PCB).

What I have found in the past with other projects is that if I have NOPROTECT as my fuse setting then it reprograms fine.

However I had put it as PROTECT, and I cant seem to overwrite now.

Any suggestions would be greately appreciated.

Thank you
a.

jfk1965 · Joined: 21 Oct 2003 Posts: 58

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

This thread has detailed instructions on how to use PicStart-Plus for ICSP:
http://www.ccsinfo.com/forum/viewtopic.php?t=5405&highlight=picstart+icsp

arrow · Joined: 17 May 2005 Posts: 213

Hi PCM Programmer and JFK1965

Thank you for your help.

a.