Hi all,

I want to measure current used by a load using an ADC.

The load is a R/C Servo (Hitech 605BB). The ADC already
exists on a micro controller which takes a voltage of
0-5V giving me a reading of 0-255. My idea was to put
a 1 Ohm resistor in series with the servo power supply
and try to measure the volt drop across it. I guess
that the volt drop would be quite small and would need
an op-amp of some sort to make the voltage change big
enough so the ADC could measure it. This is where I need
help as I don't know how to configure an op-amp in such
a way. I've tried bashing out a circuit in a demo version
of electronics workbench but without much luck.
Can anyone help in the way of a circuit diagram or
something. The op-amp would preferably only need one
positive supply rail and not a +/- supply if possible.


Any help would be greatly appreciated.

Thanks,

Russ.