provide some signal scaling so you could have a higher number of bits to work with at the A2D in the Arduino
I hoped to get a voltage change from 1 to 2 V, and be able to scale that from 1 to 4 V or even 0.1 to 4 V Could someone please help me with this ?!
Remove R4Make R2 into a potconnect the +ve of the op amp to the wiper of the pot.The pot will then control the DC offset of the signal.
recently learned that both input resistors to +vin and -vin need to be the same size, to get the voltage difference right.
confusing what you are doing with a differential amplifier
I think there's an option about having Analog Ground separate from Digital Ground, but I can't find details how to separate them,
Measure a voltage difference, wich is not bound to my GND ?
the two voltages will have a path to ground through the resistors on the front end of the op amp. You need some sort of common reference and one of the wires has to provide this.