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OnSpeed Gen3 — Open-Source AOA for GA

OnSpeed is an open-source Angle of Attack (AOA) system that gives pilots directive audio cues to maintain positive aircraft control — avoiding stalls, managing energy, and extracting maximum performance. No gauge to watch. Just listen and respond.

The system provides real-time angle-of-attack information as audio tones, derived from systems originally developed for military carrier operations. It is not a stall warning horn — it is a continuous energy-management cue that tells you how hard the wing is working at every moment.

What Does It Do?

OnSpeed continuously measures angle of attack and converts it to audio tones piped through your headset:

What You Hear What It Means What to Do
Silence Fast — below best-glide AOA No action
Slow pulsing, low tone Approaching ONSPEED — decelerating into approach range Normal deceleration
Steady tone ONSPEED — balanced effective power Hold this condition
Fast pulsing, high tone Slow — effective power is negative, unsustainable Push: add power, reduce AOA
Rapid buzz Stall imminent — at the aerodynamic limit Unload: reduce AOA immediately

Because AOA is independent of weight and G-loading, the tones work correctly in turns, at any weight, and at any altitude. No mental math required.

Learn how AOA tones work

Hardware at a Glance

The Gen3 system is built around an ESP32-S3 microcontroller with:

  • Dual pressure sensors — differential pitot and AOA ports (Honeywell HSC, 14-bit)
  • Static pressure sensor — for altitude and density corrections
  • 6-axis IMU (IMU330) — accelerometer + gyroscope at 208 Hz for AHRS
  • I2S audio output — high-quality stereo tones through your audio panel or headset
  • WiFi — configuration, calibration, and log download via web browser
  • microSD logging — 50 Hz flight data recording (40+ channels)
  • EFIS serial input — Dynon, Garmin, MGL, or VectorNav for IAS, attitude, OAT

The controller fits in a small enclosure and connects to your aircraft's pitot/static system and audio panel.

Getting Started

New to OnSpeed? Start here:

  1. What is OnSpeed? — Understand the concept
  2. System Overview — What's in the box
  3. What You Need — Prerequisites and tools
  4. Hardware Installation — Mount and wire it up
  5. Configuration — First-time setup checklist
  6. Calibration — Fly the calibration wizard
  7. Flying — Learn the tones and fly

Open Source

OnSpeed Gen3 firmware is open source under GPLv3. Hardware designs are available for builders.