Hi, All!
I need to measure the potential difference between two points. Values ??can be positive or negative.
In the datasheet for the chip ATMega2560 says that this is possible at the ADC: Differential input channels.
How to use differential channels with Arduino for my task?
Or perhaps there is a more appropriate external sensors for the task?
FreeManGH:
Values ??can be positive or negative.
Relative to what.
If you make your "most negative" point your "0volt reference point" and attach that to the arduino ground point then all other differences will be positive.
I input voltages must within certain limits. Even if you measure their difference. And your Arduino and your voltages must have a common ground so that you can tell(measure) what the voltages are.
If those voltages are too much for Arduino you can use an instrumentation amplifier for that. It is a special chip to make voltage differences to start from ground. Like 11V and 12.23456V becomes 1.23456V.
Leif