I have got a power source for my RPi. The manufacturer claims that the output voltage is exactly 5V. However, I would like to measure whether it is true, and I would like to find out how stable it is when I connect other devices. Where it is easiest to measure the voltage with a "needle" volt-metre?
I was thinking about the 5V GPIO pins but I'm not sure if the voltage there is the same as on the input to the device.