And use 4 AA batteries, instead of 2 AA batteries,this will make a 6 Volt power supply.The AD822 OP Amp needs 5 volts minimum.
And you connect the opamp output directly to an Arduino pin?With the risk of phantom powering.What is the problem in using Arduino's 5volt supply.Leo..
So i'm trying to amplify the signal from a photometric licor sensor and record it with Arduino.
I rewired the circuit by connecting v- of the amp. to Arduino's GND through the 10k resistor.
Thank you all. I rewired the circuit by connecting v- of the amp. to Arduino's GND through the 10k resistor. The voltage measured between v- and output is exactly how i wanted it to be (Doesn't max under low lights), however, readings in Arduini do not correlate to the amount of light. I think this is because Arduino's GND is different than (e.g. there is a resistor) the GND wired to the voltage meter. Any idea how to overcome this issue?BTW. how can i attach a pic to a reply? is that possible?B.
What is a "licor sensor"?
Alcohol sensor? (maybe licor -> licquor -> alcohol -> fun!)
@mrsummitville thanks a lot,- I'm using arduino's 5v now. I used batteries because i though i can use them to get an output range (0-2.5v) but i was wrong. - I think the ground should the the same, i'm just confused as where to go with the 10k resistor.- Yes i'm getting signal to the arduino from pin 1. Please see attached picture.- the purple and the gray wires coming from the BNC connector are inputs from the Li-cor sensor.Do you think the 10k resistor should be between pin1(amp) and A0(arduino)?