bioGen-EMS-2.0

bioGen-EMS 2.0 is an open-source, programmable four-channel Electrical Muscle Stimulation (EMS) toolkit for HCI research, rehabilitation experiments, interactive installations, and body-actuating games.

It builds on bioGen-EMS and works with Auto-Paizo using a shared single-character control protocol over USB serial and BLE.

Table of contents

• Features
• Circuit
• Repository layout
• Quick start
• Documentation
• Hardware requirements
• Safety
• Contributing
• License

Features

• Four-channel relay control via demultiplexer select lines (D1–D4)
• Auto-Paizo compatible commands (A/a … D/d, E/e, r) on serial and BLE
• EMG telemetry over BLE (Grove EMG on A0)
• Production firmware for Seeed XIAO nRF52840
• Python CLI for bench testing without Unity
• Open-source hardware CAD, circuit, and firmware (MIT)

Circuit

Schematic: Circuit Designs/bioGen-EMS-2.0.ckt (open in Cirkit Studio)

Repository layout

bioGen-EMS-2.0/
├── firmware/biogen_ems/    # Production sketch (Seeed XIAO nRF52840)
├── python/                 # Serial control CLI
├── examples/               # Example scripts
├── docs/                   # BOM, assembly, safety, protocol, enclosure
├── hardware/               # Hardware documentation index
├── CAD Files/              # Enclosure V2.0–V2.2 (use V2.2)
├── Circuit Designs/
└── Test Code/              # Legacy bring-up sketches (deprecated)

Quick start

1. Clone and install Python dependencies

git clone https://github.com/Integrated-Motor-Play/bioGen-EMS-2.0.git
cd bioGen-EMS-2.0
pip install -r python/requirements.txt

2. Flash firmware

1. Install the Seeed nRF52 board package in Arduino IDE.
2. Install the ArduinoBLE library from Library Manager.
3. Open firmware/biogen_ems/biogen_ems.ino.
4. Select Seeed XIAO nRF52840 and upload.

See firmware/README.md for the smoke-test checklist.

3. Control over USB serial

# List available serial ports
python python/ems_control.py --list-ports

# Pulse channel 1 for 500 ms (auto-selects first port if --port omitted)
python python/ems_control.py --port /dev/cu.usbmodem101 --pulse 1 --duration 500

# Turn channel 2 on / off
python python/ems_control.py --port /dev/cu.usbmodem101 --channel 2 --on
python python/ems_control.py --port /dev/cu.usbmodem101 --channel 2 --off

# Reset all channels
python python/ems_control.py --port /dev/cu.usbmodem101 --reset

On Windows, use COM3 (or your port) instead of /dev/cu.usbmodem101.

Example script: examples/basic_stim.py

4. Build the hardware

1. Bill of materials
2. Assembly guide
3. Enclosure V2.2 — laser-cut acrylic + 3D-printed top/base

5. Use with Auto-Paizo

Pair over BLE and run calibration before participant sessions. See docs/auto-paizo.md.

Documentation

Document	Description
docs/bom.md	Bill of materials
docs/pinout.md	MCU pin mapping
docs/protocol.md	Serial and BLE command reference
docs/assembly.md	Build order and wiring
docs/safety.md	Safety and ethics guidelines
docs/enclosure.md	V2.2 enclosure manufacturing files
docs/changelog-hardware.md	Enclosure revision history
docs/auto-paizo.md	Unity / Auto-Paizo integration
hardware/README.md	Hardware doc index
CAD Files/README.md	CAD file index

Hardware requirements

Component	Notes
Seeed XIAO nRF52840	Main controller
4× Adafruit STEMMA Relay (4409)	Per-channel switching
4-channel demux	Select lines on D1–D4
Off-the-shelf EMS/TENS unit	Stimulation source (switched by relays)
Grove EMG Detector	Optional; muscle activity on A0
Electrodes and cables	Per EMS unit manufacturer

Safety

EMS affects the human body. Read docs/safety.md before building or running studies. Use ethics approval, informed consent, conservative intensity, and never test on participants without proper calibration and supervision.

Contributing

1. Fork the repository.
2. Create a branch: git checkout -b feature/your-feature
3. Commit your changes and open a pull request.

License

MIT — see LICENSE.

Contact

hello@rakeshpatibanda.com