I'm looking at a new Due, powered by the USB port, doing nothing but writing a digital HIGH to pin 53 (not that it matters.) The output voltage (according to a good DMM) is 4.56 V. But this is a 3.3V board? How is this possible? I can write it high or low so the chip is not dead. But high is 4.56 not 3.3 V. And yes it is a Due, not a mega.
Is it a good DVM?
What do you get when you measure the 3V3 power rail?
Hi, check your DMM battery, it may be low, some DMMs start to read high if battery is failing.
Check the voltage of a fresh battery, either 1.5V or 9V. If your DMM is in error by the amount shown, then the measurements will be 50% higher.