Saturday, August 19, 2006
A note on the JDM PIC programmer board...
I did a diagnostic rundown on the board and used one of the many checks that Simon thoughtfully included. This one was the problem...
Measure the voltage between pin 5 (-) and pin 4 (+). Tick the Enable MCLR box and it should go to +12V.
I got +7.53v. That low a voltage makes PIC programming a hit or miss affair. This sort of problem had been reported regularly with laptops trying to use the JDM programmer. I had it happen with desktops.
At first I thought that it might have been just a poor serial port design in my PC even though I had an Intel motherboard in it that the serial signal was coming from. I tried it again on my new top-of-the-line Dell workstation and had the same thing happen, though. At that point I decided that the JDM card was simply obsolescent.
I'd lost a month playing guessing games with the JDM by that time so was in no mood to try building up another kit or getting another plan off of the internet. I wound up paying about US$130 for a really good ME Labs USB PIC programmer with a 40 pin ZIF socket (that lets you program PIC chips without having to use a little screwdriver to get them out of the socket). It's a lot easier on the pins. The ME Labs PIC programmer also is very forgiving. If you put in a chip backwards it politely asks you what the hell you're playing at on your PC screen instead of staging an impromptu white smoke and burned electronics event on your worktable. I've never regretted the expense for a moment.
Now I can program every PIC chip made without worrying.
I know that there are a lot of PIC programmer board designs out there that you can get both as kits or ready-to-use boards that are a lot cheaper than what I bought. I've no doubt, as well, that there are PIC programmer boards out there that are a lot better value for money. My experience is currently limited to the JDM and the MELabs, however.
Mental note #3426 Never dance in front of a camera.
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