Sat, 08.22.26 - Debugging the IC
After thinking about it for a week, I decided to make sure the IC was working correctly.
Step 1 is wiring this and instead of biasing, we’re going to just ground one input and put a square wave in the other. If this works the way it should, the output should be the same as the square wave input. This will require a little code.
Welp, seems like the obsolete chips I got on ebay don’t work very well. I’m going to try to cobble together an instrumentation amplifier from the opamps I currently have.
We did it!! Instrumentation amplifier link
Input
Output
I used two 10ks to get a gain of 2x. The only weird thing is my ref is off. Gonna try to figure that one out.
Idk if the ref problem is a circuit problem or just because my oscope is so cheap and bad. I have enough to start working through the actual EEG stuff!