LidAngle (macOS Menu Bar App)

A tiny menu bar app that displays your Mac’s current lid angle as text (e.g., 120°).

• Uses the hidden lid angle HID sensor via IOHIDManager (Vendor 0x05AC, UsagePage 0x0020, Usage 0x008A), reading Feature Report ID 1.
• No UI beyond the status item text.
• Right‑click (or control‑click) the status item to Quit.

Build & Run

• Open the Xcode project and run the LidAngle target.
• Ensure IOKit.framework is linked (Target → Build Phases → Link Binary With Libraries).
• App Sandbox is disabled in LidAngle.entitlements to allow HID access.

Behavior

• Updates the angle about twice per second.
• Shows —° if the sensor isn’t available or can’t be read.
• No left‑click action; right‑click shows a one‑item menu (Quit).

Requirements & Notes

• Hardware: Newer Mac laptops/desktops with a lid angle sensor. Some M1 models reportedly don’t expose the sensor.
• API: Relies on undocumented HID usage; not App Store–safe and may break on OS updates.
• Matching: Falls back from strict (VID+PID+Usage) to relaxed (VID+Usage) to usage‑only.

Troubleshooting

• If it always shows —°, check your hardware, confirm Sandbox is off, and verify IOKit.framework is linked. Use the Xcode console to see any read errors.

Acknowledgments

• Inspired by and built thanks to the work in LidAngleSensor. All credit for discovering and demonstrating how to use the hidden lid angle HID API goes to the original author.