mlever:
Hi,Everything was working fine, but I left my Arduino running overnight and the next day the voltage at the output pins has dropped from 5V to 3.5V, no matter what pin I choose or what sketch I run.
What was it doing overnight? - it was generating a random output voltage from 0 to 5V which was going through an op amp voltage doubler, to provide 0-10V control signal to a control valve.
Any assistance would be appreciated.
Mitch
Your battery ran down, plain and simple. You realized this, else you would have spoken up by now.