PIC18F2550 programming problem

[marcjwebbmusic]

ok so i am pretty much at the point where i am ready to play, last on the list of things to do is to upload the USB programme to the pic, made the ICSP cable, connected up checked that the interface tab was on COM84 (and it was) on port says COM1, loaded the file, (all 12mhz, 16mhz and 20mhz) however everytime says uploada failed, any help here would be great as looking to run it with my mac and SD 2 so the usb is an essential.

can anyone help on this?

Thank You
Marc

[marcjwebbmusic]

ok just noticed my pic says - PIC18F2550-i/sp, is this the problem?

[dmitri]

You're not the first with the problem. There might be many reasons. Did you look in https://www.google.co.uk/#q=site%3Awww. ... PIC18F2550 ?

[marcjwebbmusic]

ok, so from all the posts i have read alot of them say about the icsp cable being the fault and then others say the chip. i am a little confused so am going to try and programme the pic on a seporate programming board to see what happens. will keep you posted,, thanks again for your help.

[marcjwebbmusic]

ok so today i tried to programme the pic on a seporate PIC programmer board and still the same problem, so this rules out the cable im using leaving just the pic iteself and the firmware, i am going to order another pic chip to see if this is the problem, if not, then i know it will definately be the hex file.

any other suggestions at this point??

regards

marc

[dmitri]

any other suggestions at this point??

Not really.

[marcjwebbmusic]

also i was talking to someone who works very heavily with avr and embedded systems, and showed them the schematics and they pointed out that the rs232 icsp is wired in such a way that no communication would really work as is wrong.

http://www.google.co.uk/imgres?imgurl=h ... CDgQ9QEwAQ

yet the one on here shows the main pins not being used or different???

would you mind taking a look?

regards

marc

[dmitri]

I did not invent this ICSP cable, I took it from somewhere on Internet. It worked for many.

[marcjwebbmusic]

hi dmitri, hope you are well, just a quick question but it seems you had the same problem, what did you do to get over it.

"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)."

is this the process to deal with it? also what is the schematic change for it?

regards

marc

[dmitri]

You quoted the change I did and this change is included in the Latest MegaDrum schematic.