Specification
Everything in the kit, plus the web app that ties it together.
Octopus 16 EEG board (included)
| Channels | 16 EEG, dry spring-loaded pogo pins |
| ADC | 2 × Texas Instruments ADS131M08, 24-bit |
| Gain | 4 (all channels) |
| Controller | Seeed Studio XIAO ESP32-S3 |
| Wireless | Bluetooth LE, ~250 SPS |
| Bluetooth name | Octopus-16-XXXX |
| Power | 5 V power bank, battery only while worn |
Sample rate: the stream is labelled 250 SPS. With the current 8.000 MHz ADC clock the true rate is about 244 SPS (4 MHz ÷ OSR 16384). That's fine for viewing and band power; correct for it if you need precise timing (ERP, P300).
Starter Kit for Arduino (SEA0004T, included)
| Board | Arduino Uno compatible (ATmega328P) |
| Connection | USB serial, 115200 baud |
| Sensors | Ultrasonic distance, light (BH1750), temperature & humidity (DHT20), motion (PIR), sound, soil moisture, potentiometer, accelerometer (MPU6050), button, IR receiver |
| Outputs | LED, second LED, relay, buzzer, servo, 16×2 LCD |
| Firmware | OctoBio firmware, flashed once from the browser |
| Ready line | INF protocol=1 ready |
Software (web app)
| Platform | Web app at octobridge.pieeg.com (opens in a new tab), Chrome or Edge (desktop) |
| Connection | Web Bluetooth (Octopus 16) + Web Serial (starter kit), both live at once |
| Firmware | Flashed by the user from the browser, one time only |
| Programming | Blocks, 5 difficulty levels, runs live without compiling |
| EEG values | Relative band power δ θ α β γ, focus, relax, signal quality |
| Privacy | Bluetooth and USB stay in the browser tab. Nothing is uploaded to a PiEEG server. |
Octopus 16 BLE protocol
For developers who want to read the Octopus 16 in their own software.
| Item | Value |
|---|---|
| Service | 4fafc201-1fb5-459e-8fcc-c5c9c331914b |
| Data (NOTIFY) | beb5483e-36e1-4688-b7f5-ea07361b26a8 |
| Cmd (WRITE) | c0de0001-36e1-4688-b7f5-ea07361b26a8 (register bridge) |
Packet: 51 bytes, one sample per notification
| Bytes | Meaning |
|---|---|
[0] | 0xA0 start marker |
[1] | Sample counter (0–255, wraps) |
[2..25] | ADC1, channels 0–7 (8 × 3-byte big-endian signed 24-bit) |
[26..49] | ADC2, channels 8–15 |
[50] | 0xC0 end marker |
µV = raw × (1.2 / 4.0 / 8388607) × 1e6(1.2 V reference, gain 4, 24-bit.)
The easiest way to use it from a web page is the JavaScript SDK:
const eeg = new PiEEG();
await eeg.connectBLE({ device: 'octopus-16' }); // call from a click handlerPackage
| SKU | PIA24028P |
| Weight | 570 g |
| In the box | 1 × Octopus 16 EEG board (with ESP32-S3), 1 × Elecrow All-in-One Starter Kit for Arduino (SEA0004T), access to the OctoBio web app and firmware |
| Not included | 5 V power bank, a computer with Bluetooth running desktop Chrome or Edge |
| Sold by | PiEEG on Elecrow |