I have an IR detector circuit configured for line-following robotic use. (Schematic attached) This circuit feeds an Atmel AVR microcontroller - Works fine - except in cooler weather it just ceases to work. Breath on it, hold a soldering iron near it or even just leave it connected to power for 20mins and it comes right - for awhile. Even a strong light or holding the Op amp between two fingers will wake it up after a fashion.
I have spent time working through the usual power rail and component value changes in an attempt to recreate the problem at will, but no luck - The fact that the board wakes up after handling etc makes troubleshooting difficult. I have several of these boards and they all exhibit the same problem, but some are worse than others.
I tried putting one in the freezer overnight, but it worked with no problems in the morning. This made me wonder about humidity?
Has anyone got any suggestions as to cause or how I might recreate the problem at will?
I have spent time working through the usual power rail and component value changes in an attempt to recreate the problem at will, but no luck - The fact that the board wakes up after handling etc makes troubleshooting difficult. I have several of these boards and they all exhibit the same problem, but some are worse than others.
I tried putting one in the freezer overnight, but it worked with no problems in the morning. This made me wonder about humidity?
Has anyone got any suggestions as to cause or how I might recreate the problem at will?