Open-source transcranial Direct Current Stimulation (tDCS) device using the Seeed Studio XIAO BLE nRF52840.
Open-tDCS-Stack is a Bluetooth-enabled tDCS device that provides precise current control with real-time monitoring capabilities through a web interface.
- Microcontroller: Seeed Studio XIAO BLE nRF52840
- Connectivity: Bluetooth 5.0 (BLE)
- Current Range: 0-4mA (configurable)
- Battery: 4x CR2025
The firmware is located in firmware/build/opentdcs.ino.uf2
To install on the XIAO BLE nRF52840. Place it into bootloader mode by quickly pressing the reset button twice.
A XIAO USB drive will appear on your computer. Drag in the firmware/build/opentdcs.ino.uf2 file. Done
- Real-time current monitoring and control
- Battery voltage monitoring
- Impedance calculation
- Configurable session parameters (duration, ramp up/down)
- BLE GATT service for wireless control
- Visual status indication via RGB LED
| Function | Pin | Description |
|---|---|---|
| PWM Output | D3 (P0.29) | Current control signal |
| Current Sense | A0 (P0.02) | Measures output current |
| Battery Voltage | A1 (P0.03) | Battery monitoring |
| Output Voltage | A2 (P0.28) | Output voltage monitoring |
TLDR: Web UI is hosted at https://unrelatedlabs.github.io/Open-tDCS-Stack/gui/
The web GUI is located in gui/index.html and provides:
- Device connection via Web Bluetooth API
- Session control and monitoring
- Real-time current and impedance graphs
- Session history tracking
- Battery and voltage monitoring
- Open in Web Bluetooth-compatible browser (Chrome, Edge). On iOS use the V Browser https://apps.apple.com/us/app/the-v-browser/id6446792641
- Click "Connect Device" and select your tDCS device
- Configure session parameters (current, duration, ramp time)
- Start session and monitor real-time data
- This is an experimental device for research purposes only
- Always follow proper tDCS safety protocols
- Maximum current is limited to 4mA in hardware.
- Device includes impedance monitoring for electrode contact quality
- Automatic session termination on completion
[License information to be added]