EEG EGG
What is EEG?
An electroencephalogram(EEG) measures the electrical activity of the brain through electrodes attached to a person's head. It shows brain wave patterns which can be used to diagnose epilepsy, brain disorders, sleep disorders etc.
Primary Objective:
Detect brain waves and process them using the ADS1299 AFE chip
Secondary Objectives:
As the ADS is sensitive to power supply noise, isolate it by powering it through a battery
Use Fourier Transform to process EEG signals and detect certain actions in the user
Subsystems - Power Management
As the ADS is susceptible to power supply noise the power management in this board is designed to power the ADS through a battery. This circuit charges a lipo battery through USB-C which then powers the ADS. It features several voltage regulators as well as battery charging and discharging protection.
Subsystems: ADS
As EEG signals are inherently very weak, in order to produce a processable signal, these signals need to be amplified. The ADS1299 chip is able to take in the EEG signals, amplify them filter out noise and communicate this data via SPI to a microcontroller like the ESP32. The electrodes are also connected to high pass filters to further filter out noise.
Layout
BOM
A series of unfortunate events
Unfortunately we messed up some of the footprints and ended up being unable to complete the board!