Short circuiting GND and power pins I have created an arduino shield and i want to measure the voltage between the GND pin and 5V pins, to see if i see a voltage difference between the two points, in order to test if my pcb is fine.
My concern is since these are right next to each other and my multimeter probes are thick.
If the multimeter probe that 5V pin touches the GND pin, in other words, if i short circuit the 5V and GND pins, then will my arduino be safe?
I am afraid of damaging the arduino.
It all depends on how you are powering the board.
If you're running it from USB then the computer should shut off the power to the USB port. If it doesn't then the Arduino has a small self-resetting fuse on the USB power which should shut the power off for you.
However if you're powering through the barrel jack there's no protection. Worst case scenario: it will blow the voltage regulator, which then &quot;fails short&quot;, meaning it passes the whole of the input voltage through to the microcontroller, which then kills it.
So yes, it's possible to damage the Arduino with a short circuit.
Most multimeters have a better way of testing the board though: either the &quot;beepy&quot; continuity test, or the resistance mode.  You can use that to test the continuity or resistance between your 5V and GND pins without having to connect the shield to the Arduino at all. 100% safe.