Sunday, April 7, 2013

Killed another PICkit 3

I don't trust in-cicruit programming with the transformerless power supply I'm using.  I tried it once and blew up the PICkit, my usb hub, keyboard/mouse dongle, and my front usb port, along with a handful of traces on my solderless breadboard.  So what I've been doing is unplugging the circuit before I hook up the PICkit.  I've blown my triac driver circuit twice since because the AC power lines to the triac are plugged in separately.  I remember to unplug the main circuit, but leave the triac plugged in and it fries the transistor and one of the resistors.  But today, I forgot to disconnect the PICkit before I plugged the circuit back in and fried the PICkit, the pic18, probably fried some more traces on the breadboard, and it looks like both the diode and zener diode in my power supply circuit are fried as well, but I haven't tested them yet.

I need to find some way to isolate the PICkit from the rest of the circuit, but I don't know what will allow me to isolate it and still let me program it.  So I think what I'm going to have to do, and what I should have done originally, is build the bare-bones programming circuit on a separate board.  But I don't have a zif socket for this chip and that's a lot of plugging and unplugging.

I'm going to email microchip and make see if they can confirm or deny that the transorfmerless powersupply circuit works with the PICkit in-circuit programming.  If it does, then I'll just use that.  It's definitely a possibility that the problem is because I was still powering the circuit through the PICkit.  I know I was this time, and I didn't think I was last time, but I may have been.

If that doesn't work, I'm just going to have to buy 2 zif sockets.  I can't risk paying for this stupid thing again.  I have to get another chip anyway, since that was my last one.  I have some other older pic18s laying around, but they don't have as many pins.  I'll have to pull up the specs before I can see if they have enough ports to be usable.  I also have a couple of dsPIC30's that I haven't played with yet, but it seems a waste to use them for this project.  We'll see, though.