I need to measure the current drawn from the 5V pin.
I'll be powering up to 3 boards through this pin, and I only have the data for one of them. So I need to come up with a method for empirically measuring the current drawn when connecting each one of these boards individually. In my project, the Arduino will be powered with batteries.
I've connected a multimeter in series with a wire coming from Arduino's 5V to one of the other board's 5V pin. The Arduino itself was powered by USB for the test. I know the connection worked because the attached board was powered and the program flashed on the Arduino was running.
However the multimeter displayed 0 Amps :confused: I switched the multimeter knob all the way from 200uA to 200mA, yet I got no current in the display.
The multimeter works, as I've measured a battery's current through a 100k resistor.
The only knob position I didn't test was the 10A unfused, but this is meant to measure high currents (wall sockets?) and I was not sure if this experiment would damage the Arduino.
What am I doing wrong? Arduino's 5V should be DC, exactly as a battery, so the multimeter method should just work with both!