hi Zeesus,
As requested by PM, this is you circuit in LTS.
Note the very wide voltage range, especially at the lower peak, it is showing equivalence of the two signals, well outside the required +/1mV band.
E

 

Saw a way of reducing code needed, make it faster -



This is mBlock 5.0 by the way. Graphic programming of Arduino, ATTINY series.

So you would need ATTINY85 chip, a C to bypass its power rails, LED, and 5 R's, 4
to scale inputs to 0 - 5 V and one to limit LED current. You would need an Arduino
UNO or NANO to program the ATTINY85.

Note if your system is noisy easy to add an averaging loop in code to filter
out noise. That of course introduces latency, something you must consider
the tradeoff.. Also if you needed other stats, like average offset of a particular
signal, or other properties, that can be coded as well. Lots of possibilities. or
trigger another output if one signal high/low for an excessive amount of time....
You could even program the Arduino/ATTINY85 to test its operation via use
of PWMs as DACs to gen voltages to test itself.


Regards, Dana.