Work in progress This site is under construction — content, figures and specifications are provisional.
PFD · ch.flysys.pfd

Primary flight display for experimental aircraft.

Attitude, ground speed, altitude, vertical speed, slip and heading — estimated on-device from an external BLE IMU and rendered in OpenGL ES 3. No moving map, no engine page. One instrument, done precisely.

Experimental · not certified for primary reference

Fig.01 — Attitude Displaylive · ESKF
FlySys PFD in a steep right bank, horizon diagonal, heading 241°
Live capture · BLE source, ESKF estimator — right bank ~45°, HDG 241°, QNH 1013 mbar.
1Heading band°M
2Roll scale & pitch ladder±60°
3Ground-speed / GPS tapekm/h
4Barometric altitude + VSIm · m/s
5Slip & turn-rate°/s
30
Render rate · Hz
4
Attitude filters
6
Data sources
8.1
Android · minimum
In flight

From level to the turn.

Wings levelHDG 230
FlySys PFD with wings level, horizon centred, heading 230°
Turn-rate & slipHDG 110
FlySys PFD in a right turn, slip ball deflected — turn-rate and slip indicators active
§1 · Signal path

From sensor sample to drawn frame.

The same processing runs live and in offline replay — so the display you fly is exactly the display you can reproduce afterwards from a recorded log.

Fig.02 — Data flowlive = replay
GPS + BARO CONTEXT DATA SOURCE BLE · internal · sim · replay IMU PROCESSOR ESKF · CF · Madgwick · FW HORIZON RENDERER per-frame state OPENGL PFD 30 Hz · render-on-dirty INDISPLAY
§2 · Specification

The numbers, on one page.

A self-contained Android application. The display you fly is validated offline against recorded flight logs — identical processing, reproducible result.

Requirements
Android version8.1 or newer
RecommendedAndroid 10 +
External IMUBluetooth LE (primary path)
Without hardwareinternal sensors · sim · replay
GraphicsOpenGL ES 3.0
Flight logsCSV → Documents/PFD/

A focused instrument, documented in full.

Every instrument, the four attitude estimators and how each one works.