Compass not detected on DAKEFPV F405 (ArduPilot 2026-07)

[shashanknaik819-commits]

Hardware

• Flight Controller: DAKEFPV F405
• Compass: HGLRC M100-5883 (6-wire, I2C)
• ArduPilot version: 2026-07 (latest stable)

Issue

Compass is not detected in ArduPilot. PreArm error: "Compass 1 not healthy"

• COMPASS_DEV_ID = 0
• xmag, ymag, zmag all = 0

Wiring verified

• GND, 5V, TX (TX4), RX (RX4), SDA, SCL all connected correctly

Firmware comparison

• ✅ Betaflight: Magnetometer detected
• ✅ INAV: Compass detected immediately
• ❌ ArduPilot: Never detects compass

All tested on same hardware, same wiring.

Steps to reproduce

1. Connect HGLRC M100-5883 to DAKEFPV F405 via I2C
2. Load ArduPilot 2026-07
3. Check COMPASS_DEV_ID parameter → shows 0
4. PreArm fails: "Compass 1 not healthy"

Parameters checked

• COMPASS_ENABLE = 1 ✅
• COMPASS_DISBLMSK = 0 ✅

Issue appears specific to ArduPilot on this target.