https://swharden.com/blog/2019-03-15-sound-card-ecg-with-ad8232/ It is interesting to test it, to replace the sound card by a 16 bit a/d converter, make a 3 lead ECG device out of it, test a variant with the DFROBOT optical heart rate sensor, test it with HeartPy, attach it to an ESP32 module and Home Assistant, export sensor data to InfluxDB, …