[sciguy125]

Alright, the supply is clean. Well, if I put my scope at 5ns, it doesn't see any noise. I have capacitors right at my voltage regulators and right next to the PIC. Adding more does nothing, removing them increases the problem very little. So, I've ruled out a problem with the voltage supply. However, I have yet to rule out a problem with the power line as it seems to be the main culprit.

Using the internal oscillator in the PIC does nothing to solve the problem. That was one of the first things I checked. Just for kicks, I've even tried 15 different crystals at three different frequencies. I'm using 33pF caps with the crystal. According to the datasheet, I should be using 15pF with the 20MHz. I think that's close enough to the 27pF for the 4MHz crystals. But, again, changing the clock frequency doesn't fix the problem. The only change to the PIC that seems to have any effect is disabling brown out detection.

I've done PIC projects before, but havnen't had this problem. The two differences now are the PIC and my board. I don't have time right now, but this weekend, I'll try to dig up some other PICs and my other board.

Per Al's suggestion, I unplugged everything for the aquarium that's sharing the same socket I'm using. It didn't do anything. I also tried unplugging my wireless router. There's still plenty for my to try, but again, I think I'll have to wait for the weekend.