I have tried to measure current using SparkFun Hall-Effect Current Sensor Breakout - ACS712 and also tried using shunt resistor. It seems that each measured value is different from what I measured by multimeter. And I don't know which one is showing the correct value.
Is there any simple solution for measuring a current? Also possibly more importantly, how can I test that the measured value is correct?
I want to start with a very simple circuit to test the current measurement and if it's verified that the measured value is correct, then I want to hook it up to the actual device, so that I don't damage the device accidentally.
Any suggestion is greatly appreciated.