Discussion in 'The Projects Forum' started by Cerkit, Jan 11, 2009.
How can I setup an ADC to be a voltmeter and current meter together??
It can only convert voltage - you have to use the current through a resistor for the measurement. Current through a resistor makes a voltage across the resistor proportional to the current. A small value resistor will not disturb the circuit too much, and a good quality op amp can make the voltage large enough for the ADC to handle.
Ok. So assuming I do that would it would be possible to alternate the input to the ADC depending on whether I want to measure voltage or current. Using a decoder on the input signal for instance??
You can make it by using a simple SPDT switch.
Yes, with an analog switch, or with a microprocessor that has a built-in A to D and multiple switched inputs to it.