Heatermeter troubles - No Communication after a while on hot days

[David Pagels]

Since I built my Heatermeter a couple of years ago, it works like a champ whenever I use it on a chilly day. I even used it for a week straight in the fall last year to make sure some concrete I poured was staying warm enough and it never choked. Now that it's getting to be summer again, whenever I use my Heatermeter and it's above 70 outside, after a few hours the RPI will lose communication with the avr and the Heatermeter will start acting strangely and showing odd symbols on the screen, hang, or just crash and show nothing at all. I'm doing some troubleshooting today and have started by powering on the Heatermeter with the blower not attached to isolate the problem from something to do with that. About an hour later, in the luci/admin config screen, It's showing no communication. Any ideas of things to try? I've re-flowed the soldering joints a couple of times with no change in behavior. Do I just have a bad atmega chip?

 

[David Pagels]

When I brought the Heatermeter inside after that first test, I also noticed the power supply was pretty hot. Now that it's cooled down and working again, I put the Heatermeter back outside, but put the power supply in the shade in the garage to see if that's the culprit.