MacSense - Lifting the lid on hidden sensor in MacBooks

Tilt your MacBook like a phone. Read the built-in IMU, send MIDI, move the cursor, and run browser demos — all powered by the undocumented Apple Silicon accelerometer.

Projects

Directory	Description
apple-silicon-accelerometer/	Core Python driver (macimu) — reads accelerometer, gyroscope, lid angle, and ambient light via IOKit HID
apple-silicon-sensor-to-midi/	Streams IMU orientation as MIDI pitch bend to a virtual port
apple-silicon-sensor-to-hid/	Controls the mouse cursor by tilting the laptop
demos/	Standalone HTML demos (see below)

Credits

The sensor access in this project is built on macimu by @olvvier — a Python driver that reads the undocumented Apple Silicon SPU accelerometer and gyroscope via IOKit HID at ~800 Hz.

Prerequisites

• Apple Silicon MacBook (M2 / M3 / M4 / M5)
• macOS
• sudo access (required for sensor reads)
• Python 3.12+ and uv for the Python projects

Quick Start — Python Projects

Accelerometer driver + demo dashboard

cd apple-silicon-accelerometer
python3 -m venv .venv && source .venv/bin/activate
pip install -e .[demo]
sudo .venv/bin/python3 motion_live.py

Sensor to MIDI

cd apple-silicon-sensor-to-midi
uv sync
sudo uv run main.py midi

Opens a virtual MIDI port called apple-silicon-sensors visible in any DAW or MIDI Monitor.app.

Sensor to mouse

cd apple-silicon-sensor-to-hid
uv sync
sudo uv run main.py mouse

Requires Accessibility permissions for your terminal (System Settings → Privacy & Security → Accessibility).

Demos

Browser-based demos that visualise sensor data. Each demo is a single index.html file — just open it or serve it locally.

Starting a demo

Open any demo directly in your browser:

open demos/perspective-demo/index.html

Or serve the demos folder over HTTP (useful for features that require a secure context like device motion):

python3 -m http.server 8000 -d demos

Then visit http://localhost:8000/perspective-demo/ in your browser.

Available demos

The demos take inspiration from internet classics:

Demo	Description
perspective-demo/	CSS 3D perspective transforms controlled by sliders or MIDI pitch bend
paralax-demo/	Parallax window scene with layered sky, mountains, and trees reacting to pitch and yaw
sound-demo/	Plays preloaded WAV files (Wilhelm Scream) when acceleration spikes above an adaptive threshold — inspired by the screaming Roomba
synth-demo/	Synthesizer demo
beer-demo/	Tilt-reactive beer simulation — inspired by the classic iBeer iPhone app

Connecting demos to sensors

The perspective and parallax demos accept MIDI pitch bend input. To control them with your MacBook's IMU:

1. Start the MIDI bridge: sudo uv run main.py midi (in apple-silicon-sensor-to-midi/)
2. Open the demo in a browser that supports Web MIDI (Chrome, Edge)
3. Tilt your MacBook — the demo reacts in real time

The sound demo also uses MIDI input — it listens for acceleration pitch bend messages on channel 5 and plays WAV files when the value spikes above the adaptive threshold.

License

MIT