At my solar repeater sites, I have APRS digipeaters that are currently monitoring solar voltage and battery voltage.   The APRS TNC is watching a 0-5 volt variable telemetry line.   I would like to integrate current monitoring as well which would in turn be quite helpful.   The thought of using a shunt which in turn would show Mv voltages is fine, but I would need to isolate that voltage from the TNC's typical ground.   

So in turn what I need to ask is, has anyone been able to pull current readings and use it via telemetry readings?   Would a 1:1 transformer be able to do this without causing a direct short?  what would I need to do to have that variable voltage (no more than 5 volts) be able to go to a TNC that is standard 12 volt with ground?

My mind is a fuzz of thoughts, and I am just not picturing what to do.    

Feel free to contact me if you have any questions.

Keri 

N2KNK