Moved butterworth over to ESP32

A project log for ESP Heart Rate Monitor

Updates browser couple times a second with realtime heartrate graph, displays heartrate and oxygen concentration. 03/04/2019 at 00:270 Comments

The process of moving my filtering from JS up to the esp went very smooth. I couldn't get the esp8266 to hold it but had no problem with the esp32.

Currently am using a 100Hz 2nd order butterworth with poles at 0.5 and 25 Hz. Raw data averages are needed on the client side to calculate SpO2 concentration and adjust led brightness which are calculated by the esp and transmitted in the tcp return packet.

Also learning my way around github and plan to pub code and instructions shortly.