Octopus 16
16 channels of EEG in a coin-sized sensor.
Octopus 16 packs sixteen EEG electrodes, a reference and a ground into a single 26 mm round board: a cluster of spring-loaded pogo pins that press through the hair onto the scalp. No gel, no cap and no ear clips. Two Texas Instruments ADS131M08 converters measure all 16 channels, and a Seeed Studio XIAO ESP32-S3 on top streams them over Bluetooth LE straight to the browser.
⚠️
Octopus 16 is not a medical device. While it's on a head, it runs from a power bank only, never plugged into a computer or a wall charger. Read Safety before the first recording.
At a glance
| Channels | 16, plus reference and ground, all in the same cluster |
| Electrodes | 18 dry spring-loaded pogo pins, 4 × 11 mm |
| Converters | 2 × TI ADS131M08, 24-bit, simultaneous sampling |
| Sample rate | 250 SPS |
| Board | 26 mm round, 4 layers |
| Controller | Seeed Studio XIAO ESP32-S3 (not included) |
| Wireless | Bluetooth LE 5, appears as Octopus-16-XXXX |
| Power | Small 5 V power bank, battery only while worn |
| Software | PiEEG Cloud, octoBridge, JavaScript SDK, Python SDK |
How it works
One sensor, one controller, one power bank, no cables to the computer.
18 pogo pins ─► 2 × ADS131M08 ─► XIAO ESP32-S3 ─► Bluetooth LE
(16 ch + REF + GND) ▲ │
│ ├ cloud.pieeg.com
5 V power bank ─────────┘ ├ octobridge.pieeg.com
├ JavaScript SDK
└ Python SDK- Touch: the pogo pins press through the hair onto the scalp. Reference and ground are in the same cluster, so no other electrodes are needed.
- Measure: two ADS131M08 chips digitise 8 channels each, 250 times per second.
- Send: the XIAO ESP32-S3 streams every sample over Bluetooth LE to a browser tab or your own code.
Octopus 16 or a cap-based board?
| PiEEG-16 / IronBCI-8 | Octopus 16 | |
|---|---|---|
| Electrodes | Separate electrodes in a cap, ear clips for reference and bias | Built in: 18 pogo pins on the board |
| Coverage | Spread over the whole head | One local spot (about 2 × 2 cm), for example over Pz |
| Setup time | Minutes (cap, gel, clips) | Seconds: strap it on |
| Wireless | PiEEG-16: no · IronBCI-8: yes | Yes (BLE 5) |
| Best for | Full-head research | Quick tests, classrooms, neurofeedback, a "brain stethoscope" |
What you can measure
| Signal | What it shows | Typical first test |
|---|---|---|
| EEG | Local brain rhythms: delta, theta, alpha, beta, gamma | Place over Pz, close your eyes, watch alpha (8–13 Hz) rise |
| Artifacts | Blinks and jaw clenches | Place over the forehead (Fp) and blink |
| EMG | Muscle activity under the sensor | Clench the jaw |
See real recordings in Signals & Datasets.
Get started
Videos
Related
- OctoBio Kit: Octopus 16 plus an Arduino starter kit, for the classroom
- octoBridge: the browser lab with block programming
- PiEEG Cloud: dashboards, experiences and Buddy AI in the browser
- JavaScript SDK:
device: 'octopus-16' - GitHub: Octopus_16 (opens in a new tab): firmware source, Python SDK, datasets
- 3D models on Thingiverse: Octopus 16 (opens in a new tab) · boxes (opens in a new tab)
- Buy from the PiEEG shop (opens in a new tab)
Support
- Discord: discord.gg/5Ps24p47 (opens in a new tab)
- GitHub: github.com/pieeg-club (opens in a new tab)
- Email: pieeg@pieeg.com