I have some control board equipped with a microcontroller.
This control board is supplied by 24V voltage source. I
would like to measure signals on some microcontroller's
output pin with a digital oscilloscope.
I have only two common probes with earthed crocodile jack connector. I am not sure whether the measurement with a probe connected to the output pin and crocodile jack connector connected to minus pole of the voltage source is correct.
Would be better to use both probes with their crocodile jacks connected together and then connect the first probe on the microcontroller's output pin, the second probe to the minus pole of the voltage source and use ChA-ChB function?