ESP32,PPG, ECG & EEG for Hackers

Last Updated on January 18, 2023 by pg@petergamma.org

  • How to Electronics from India and others showed great examples how to connect ECG and PPG HRMs to ESP32
  • ESP32 modules can easily be connected to Home Assistant
  • ESP32 modules have BLE and WIFI
  • If we connect PPG, ECG and EEG modules over ESP32 to Home Assistant, whe sould have a multi-sensor physiological Home Assistant device, from which sensor data can be exported to InfluxDB, similar to the demo of Udo Berndt on smart-live.de for the Apple watch.
  • There is an instruction for EEG and ESP32 on HackEEG:

https://hackaday.io/project/178007-esp32-eeg

  • it has 3k views, 0 comments and 264 followers and 22 likes.
  • This project was created on 03/03/2021 and last updated 2 years ago.

Description:

“I want an EEG to play with for BCI applications. Research/medical grade EEGs are not in my budget, and consumer EEGs are all some combination of over-priced/unsupportive of hacking (muse) or only have a single channel (neurosky/TGAM).

OpenBCI is on the verge of being accessible to low-budget hackers like myself with a 4-channel board at $250 (ganglion) and an 8-channel board for $500 (cyton), but those are still out of my (and probably most makers) budget for something I may not even really get too much utility from. OpenBCI is of course laudable for providing a very well maintained repo of design files and firmware for their products, so at one time it was possible to DIY their boards. Now the issue is the main microcontroller/BLE modules used in their boards are obsolete and hard to come by. So in my opinion it’s time to remake their AFE designs (specifically the ganglion board) to be accessible to interface with any generic microcontroller dev board. I’ll be using an ESP32.

I basically copied the Ganglion design, but removed the SD card holder, accelerometer, and the obsolete bluetooth/microcontroller module. I also hard wired all the instrumentation inverting inputs to the reference voltage since I only plan to do single-ended sensing. I was able to squeeze everything in to a pretty tight 2-layer board. I haven’t worked out the math yet but at ~$2 per board (including shipping), 4 instrumentation amp ICs and a few other $2-$3 ICs, and the main AFE chip (MCP3912) the whole thing comes out to be probably $20-$30 bucks, so easily in most people’s budgets.

8 channel EEG streaming with ESP32 on the YouTube channel of Preston:

Prestons channel shows no other videos. Prestons team consist of 3 members.

We are no hackers, but Prestons instruction is interesting for us personally, since he uses ESP32 modules which can be connected to Home Assistant. Preston got a setup for streaming 8 channels by using two separate 4 channel OpenBCI Ganglion boards, connected to the ESP32 on the same SPI port but with different select lines.