Micro Pi Zero Drone - Compass not healthy

[Don]

I am building the Micro Pi Zero Drone kit. I’m having trouble with the Compass’. Neither the internal to the Matek F405 HDTE or external (GPS) are being detected. That said, the course video indicates just using one Compass.

So, I built the drone, did all the checks but was, and still am, consistently getting ‘Compass not Healthy’ message (Mission Planner). I had assumed this was just due to the fact the compass had not been calibrated. After everything was together, I started the calibration process. Accelerometers worked fine …. Compass however didn’t exist (Either the onboard, as part of Matek F405 HDTE or the external, as part of the GPS).

Any debugging suggestions?

[jax200]

Are you sure this FC has an on-board compass? The specs do not indicate this.

Ardupilot.org states this means “Compass not healthy : the compass sensor is reporting that it is unhealthy which is a sign of a hardware failure.”

Go to the MP Messags tab on boot-up. What does it show regarding the compass? Maybe post a screenshot?

Regardless, possible reasons might include:

• Defective compass. Are you getting power to the GPS/Compass unit (LED on)? Do you have another you could swap with to confirm?

• Defective wiring of GPS/compass to FC. Is the power LED on? You can check for continuity for other possible wiring defects.
  https://dojofordrones.com/topic/full-build-instructions/
  https://www.youtube.com/watch?v=nrphu76jOgk Not Pixhawk

• UART settings incorrect in MP. What are your MP serial port settings, eg, Serial 3? Did you remember to write changes to the board?
  https://www.youtube.com/watch?v=0xPQ__RNwNs&t=48s 33:14 - 36:25
  https://ardupilot.org/copter/docs/common-matekf405-te.html?highlight=matek+f405+hdte

• Could you share a screenshot of the MP Compass Setup?

• Bad soldering to FC.

• FC trace wiring is incorrect. I have seen this with other Matek boards where the connection was not as labeled.

• Environmental, eg, near strong mag field

That’s all I can think of. Maybe something here will help.

[Don]

Hi Jack/Caleb,

Thank you so much for the timely responses!!!

BLUF SCL and SDA Swapped.

Caleb sent me down the right track to determine the root cause. First off, I was thinking PixHawk regarding the onboard compass… bad assumption on my part. Next, I checked the wiring again, as he suggested. Was about to send pics, but decided to take it a step further…

Using my PixHawk drone I was able to determine the pinout number/color. It would appear, that the Wiring Diagram in the Micro Pi Drone is incorrect (I2C pins reversed).

Flies like a champ now!

Thanks so much,
~Don