Hi!
I am trying to use MCP3421 in order to monitor Battery voltage.
All are fine when i use external battery with no common wiring with the main sytem. The problem begins when i am measuring the system battery.
Here is the diagram Dropbox - mcp3421-gauge.jpg - Simplify your life
Arduino does not run. Is there wiring problem?
I tried to power first the arduino and then connect battery contacts to ADC chip mcp3421 and it works fine. So why do i have to power arduino and theN connect battery to ADC Analog inputs?