PIC18F2550 programming problem

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Re: PIC18F2550 programming problem

Postby marcjwebbmusic » Thu Oct 03, 2013 11:01 am

oh ok, would you mind linking me to it, as i can only see the PDF of the original
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Re: PIC18F2550 programming problem

Postby dmitri » Thu Oct 03, 2013 11:09 am

It's right at the top of this forum: Latest MegaDrum schematics. 32 inputs.
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Re: PIC18F2550 programming problem

Postby marcjwebbmusic » Thu Oct 03, 2013 11:13 am

ok, thats the one i have been using though with no succsess, you mentioned about a 47k between some pins? is there a schematic for that one with ues for the new hex file?
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Re: PIC18F2550 programming problem

Postby dmitri » Thu Oct 03, 2013 4:07 pm

It's right there in the schematic, between ground and pin 26.
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Re: PIC18F2550 programming problem

Postby marcjwebbmusic » Thu Oct 03, 2013 4:23 pm

i am a little confused as the schematic for the cable just shows 3 10k resistors?
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Re: PIC18F2550 programming problem

Postby dmitri » Thu Oct 03, 2013 5:25 pm

marcjwebbmusic wrote:i am a little confused as the schematic for the cable just shows 3 10k resistors?

Correct. And why not?
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Re: PIC18F2550 programming problem

Postby marcjwebbmusic » Thu Oct 03, 2013 6:38 pm

because that does not show a 22k or 47k that you were talking about in a previous posting
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Re: PIC18F2550 programming problem

Postby marcjwebbmusic » Thu Oct 03, 2013 7:21 pm

pin 26 should be connected over a 22k-47k resistor to ground instead.


however, which one is that replacing?

also am i right in saying its the 9 pin connector not the parallel one? as that could also be the case as i am using the 9 pin

regards

Marc
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Re: PIC18F2550 programming problem

Postby dmitri » Thu Oct 03, 2013 7:56 pm

The 47k resistor is between ground and pin 26 of the PIC chip. And it is only for normal USB operation when PIC is already programmed. It has nothing to do with ICSP cable. Where did you read that I, or anybody else, talk about the 47k resistor in conjunction with the ICSP cable and programming?
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Re: PIC18F2550 programming problem

Postby marcjwebbmusic » Thu Oct 03, 2013 10:22 pm

By now several people have had the same problem I had and all of them confirmed that this PIC18F2550 USB MIDI firmware fixes it, of course, with the required small schematic change (pin 26 should be connected over a 22k-47k resistor to the ground).


this was taken from the first post within the link you sent,

can i just ask what you did differently to get it to programme properly without failing?

thanks for your support

Regards

Marc
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