L431 node - i2c compasses not working

Hardware CAN Devices
1

I am setting up a large VTOL plane and am struggling to get I2C compasses to be visible on the canbus.

I tried 1.4.1 and also the latest 1.5 and neither seem to do anything with connected i2c devices.

Using a holybro F9P with IST8310 compass connected to the UART port on an L431.
I have also tried other i2c compasses)

I can see the GPS great but the i2c compass does not register and does not appear in the HWID list in mission planner. I assumed the compass would be fairly plug and play. I have also tried a matek i2c airspeed sensor which on i2c which does not appear.

Has anyone tested i2c functionality and found that it works?

Is there something specific required to enable these devices?

2

Hello,

First, does the GPS/Compass works ok if connected directly to FC ?
Next, have you flashed with Latest release:
ArduPilot firmware : /AP_Periph/latest/MatekL431-GPS

Then check the bitmask to make sure the IST8310 and CANBUS are not disabled
https://ardupilot.org/plane/docs/parameters.html#compass-typemask

Finally you can check if devices appears on CANb using the DroneCan GUI
https://ardupilot.org/copter/docs/common-uavcan-gui.html

3

Hi @ppoirier
Thanks for the reply.

Yes - If I connect the Holybro f9p direct to FC GPS2 the GPS works and the compass appears in the HWID list as I would expect.

Yes I have tried the latest 1.5.482b7d74 and the behaviour is the same - GPS works, compass does not show up.

I have tried the typemask at 32, 0 and 512895 no difference to result.

In the dronecan GUI I go to bus monitor and look at data-types. I do not see any compass mesages. Is there anywhere else I should look?

I have a here3 which I am plugging into the can network to test.
The compass from that appears in the HWID list without issue.

4

Hello

Might be a bug, I suggest you jump on the discord channel to get dev support

5

Thanks. Will follow this up after Christmas as it would be great to get to the bottom of it.