Hi Guys,Would it be possible to be measure voltage and current with my arduino using the analog input pins? I'd like to measure a voltage between 0-9V, and a current between 0 and 30mA. The numbers aren't too extreme so would this be possible without using any other special ic's ?
You want the smallest possible resistor for measuring the current, but as the resistor gets smaller the accuracy drops. If you use a 1 ohm resistor then each unit of analogRead of the pin connected to the current sensing resistor is around 5ma. A 5.1 ohms resistor gives around 1ma for each unit of analogRead.
If I take a wire from ground to the one side of the led and and the other side of the led to another analog input to measure it, it seems to short out the led. I hope this made sense ...Can I measure the voltage over the led with the same setup ?