Hello Folks, I wrote some code and have it running all well and good as long as I use the USB for power. When I use an external power supply of 9VDC, my millis()counts are like twice as long. This screws up my program big time. I tried two separate power supplies. I checked the waveforms with a scope and the voltage looks clean.
Can you tell me why millis() would have different values when using either the USB or a Wall Wart for power? Thanks very much for your input!