My setup is: "Raspberry Pi Zero W" + "MCP3008" + "AD8232" (https://learn.sparkfun.com/tutorials/ad8232-heart-rate-monitor-hookup-guide/all).
A few days ago I was able to read ECG signal and print it on the monitor in python. But now when I connect electrodes to ad8232 it doesn't even detect my pulse (its diode isn't pulsing". Ad8232 still works perfectly fine with Arduino Uno.
I tested it also with my second raspberry pi zero w (same sd card) and it also doesn't work.
Could it be the fault of me putting this: