Just got the arduino and am starting to play with it. My question is an 'EE' one in general but should apply to anybody using this kit..
We have analog outputs which can be set between 0..5V. I actually need to change this range to accommodate for 2 different analog voltmeters with the following scales:
A. -3V to +3V; hence when the arduino pin output is 0V the voltmeter should measure -3V, when it's +5V the voltage should read +3V. B. 0V to +30V; when the arduino pin output is 0V the voltmeter should measure 0V, when it's +5V the voltmeter should read +30V.
The reason I mention specifically that an analog voltmeter panel is used is that (i think) the load is small due to the high impedance of the voltmeter.
I've looked around and it seems I might need an inverting OpAmp circuit, a non-inverting one, etc. Usually OpAmps take +/-15V for operating, which is another problem..