hoh-game 1.4.4

HKIE BME Dual Grip Game - A kid-friendly game for controlling exoskeleton hand braces using EMG sensors

HKIE BME HOH Game

Cross-platform Python game for the HKIE BME booth. It uses two EMG channels (flexor/extensor) to control one exo hand over BLE and guides users through repeatable flexion/extension cycles to earn stars.

The app runs on macOS, Ubuntu, and Windows, defaults to full-screen, and supports simulation mode when hardware is not connected.

Highlights

• One-hand control loop using two EMG channels: emg_flexor and emg_extensor
• BLE device scan/bind flow for EMGS + exo-hand devices
• Real-time EMG bars, raw EMG charts, circular hand-position gauge, and star progress
• Start/Stop output safety control and quick Reset
• Optional mirrored layout for left/right operator preference
• Simulation mode for testing without BLE hardware

Project Layout

• app/__main__.py - app entrypoint and runtime wiring
• app/game/scenes.py - gameplay + settings scenes and UI behavior
• app/ble/ble_manager.py - BLE orchestration and scanning/binding
• app/ble/emgs_client.py - EMGS UART command/notification helpers
• app/ble/exo_client.py - exo-hand client command/feedback handling
• app/io/input_manager.py - EMG processing and normalization
• app/ui/widgets.py - reusable Pygame widgets
• config/devices.sample.json - sample device/config template

EMG Porting Guide

For colleagues implementing the same control behavior in another language, see:

• docs/emg_control_reference.md

It focuses on:

• channel-specific EMG callbacks (_on_flexor_emg, _on_extensor_emg)
• signal processing (EMGProcessor.update_batch, dynamic MVC update)
• game control mapping (_choose_active_muscle, GameScene.update)

Install

Option 1 (from Git)

pip install git+https://github.com/o0fung/hkie_bme_hoh.git

Run:

run_hoh_game

Option 2 (local source)

git clone https://github.com/o0fung/hkie_bme_hoh.git
cd hkie_bme_hoh
python -m venv .venv
source .venv/bin/activate            # Windows: .venv\Scripts\activate
pip install -e .

Run:

run_hoh_game

Run Modes

Full-screen (default):

python -m app

Windowed:

GAME_FULLSCREEN=0 python -m app
# Windows PowerShell:
# $env:GAME_FULLSCREEN=0; python -m app

Configuration

At startup, the app expects config/devices.json in the current working directory. If it does not exist, it attempts to create it from config/devices.sample.json (or built-in defaults as fallback).

Config schema (from config/devices.json)

{
  "simulation": false,
  "settings": {
    "emg_max_range_flexor": 100,
    "emg_max_range_extensor": 100,
    "hand_start_percent": 70,
    "threshold_percent": 20,
    "countdown_seconds": 3,
    "target_flexion_percent": 90,
    "target_extension_percent": 30,
    "grip_step_percent": 1,
    "command_rate_hz": 10,
    "activation_hysteresis_percent": 2,
    "deactivation_hysteresis_percent": 5,
    "dynamic_mvc_alpha_up": 0.2,
    "dynamic_mvc_alpha_down": 0.01,
    "dynamic_mvc_up_margin_ratio": 0.03,
    "dynamic_mvc_hold_activity_ratio": 0.85,
    "dynamic_mvc_decay_trigger_ratio": 0.6,
    "dynamic_mvc_decay_grace_seconds": 2.0
  },
  "emg_flexor": {
    "name": "EMGS",
    "mac_address": "E2:15:14:6B:66:E9",
    "service_uuid": "",
    "write_characteristic_uuid": "6e400002-b5a3-f393-e0a9-e50e24dcca9e",
    "notify_characteristic_uuid": "6e400003-b5a3-f393-e0a9-e50e24dcca9e"
  },
  "emg_extensor": {
    "name": "EMGS",
    "mac_address": "EA:5E:82:04:33:79",
    "service_uuid": "",
    "write_characteristic_uuid": "6e400002-b5a3-f393-e0a9-e50e24dcca9e",
    "notify_characteristic_uuid": "6e400003-b5a3-f393-e0a9-e50e24dcca9e"
  },
  "exo_hand": {
    "name": "Exo-Hand",
    "mac_address": "08:F9:E0:EC:41:3A",
    "service_uuid": "",
    "write_characteristic_uuid": "484f4802-4200-4c00-4500-000032303233",
    "feedback_characteristic_uuid": "484f4803-4200-4c00-4500-000032303233"
  }
}

Notes:

• Backward compatibility exists for legacy settings.target_close_percent.
• simulation accepts boolean or string values like "true" / "false".

Controls

• ESC - quit
• F11 - toggle full-screen
• On-screen buttons - Settings, Reset, Start/Stop, Mirror, Exit
• Simulation keyboard input:
  • Hold F for flexor activation
  • Hold E for extensor activation

Gameplay Cycle

Each star requires a two-phase cycle on one exo hand:

1. Flexion phase: reach and hold at/above target_flexion_percent.
2. Extension phase: reach and hold at/below target_extension_percent.
3. Complete both phases to earn one star.
4. Earn 3 stars to complete the session.

BLE Tips

• macOS: allow Bluetooth access for Terminal/app in Privacy settings.
• Ubuntu: ensure BlueZ is installed and adapter is enabled.
• Windows: ensure Bluetooth is enabled and adapter drivers are working.
• If scan results are empty, move closer, power-cycle devices, and scan again.

Troubleshooting

• No window or blank display: try windowed mode (GAME_FULLSCREEN=0).
• Import/runtime errors: verify active venv and reinstall (pip install -e .).
• No simulation response: click the game window to focus, then use F / E.
• No BLE data: verify MAC/UUID config and system Bluetooth permissions.

License

MIT