Overview
The Biopotential AFE is a single channel analog front-end (AFE) that can be used not only for EEG, but also EMG (electromyography), EOG (electroocoulogram) and ECG (electrocardiogram). This board can be interfaced easily with MCU's (microcontroller unit) that have the common i2c peripheral (Inter-Integrated Circuit).
The module uses a low-power precision instrumentation amplifier and an integrated 24-bit ADC (analog-to-digital converter - Texas Instruments ADS1219) that can sample up to 1000Hz. Because of the high speed sample rate, ADC resolution and voltage amplification, the board provides a wide coverage of bioptential signals.
The board also features a high-performance 3-axis accelerometer for motion detection, useful for detecting things like head or body movement changes during sleep.
Connectivity
The board can be connected to pretty much any MCU that has the i2C prehipheral. It is also a solder-less design and connectivity to an MCU board is via a Stemma QT/Quiic cable. Sensors are connected using the onboard 3.5mm jack.
Kit
You can purchase the module alone or as part of a kit, which also includes a Stemma QT cable, a 3.5mm sensor cable with snap fitting, and 6 silver-chloride gel electrodes to get you started.
Firmware
To make things easier to start with, I've uploaded some example Arduino based firmware and also a python script that shows how to acquire an EEG signal and process it to show a spectrogram:
https://github.com/jabituyaben/Biopotential-Recorder-ADS1219
The functions used with the Arduino code should be universal and work on most Arduino platforms without issue. It can also be easily adapted to work for ECG and EMG etc.
More Info
https://www.majorinput.co.uk/post/new-eeg-biopotential-breakout-board
ADS129 Datasheet