Hello, I found a project online and I was wondering what is happening in one of the parts of the circuit. The picture was included.

What I would like to know is what are the op amps doing and what component is being represented as 10M. I thought it was a resistor but every resistor is represent by the letter R meaning it should be something else. I thought the configuration was the one of a Differential Amplifier but I am not sure if this is right

 

They are inverting buffers, dividing the input voltage by 4.7 and providing a low impedance output to feed the ADC.
I don't know what the 10M components are. As the input impedance of of the buffers is only 47K, putting 10M resistors in parallel with that wouldn't make much difference.

 

Those are not traditional diff amp configurations. What are the input signals? Voltage range? What is the voltage source? Specifically, is it a high or low impedance source?

And, what is the circuit supposed to do?

ak

 

Those are not traditional diff amp configurations. What are the input signals? Voltage range? What is the voltage source? Specifically, is it a high or low impedance source?

And, what is the circuit supposed to do?

ak

The circuit is basically taking an analog signal and sending it to a microcontroller to convert to digital, then it is sent to a bluetooth device which communicates with an android app and displays the analog representation