PX4-v2 with MPU9250 on arduplane 3.7

ArduPlane
1

I have a PX4-v2 based ardupilot and am running arduplane 3.7 with some custom code/flight modes etc. I do not want to switch to 3.8 or higher because it would likely break the aforementioned custom code due to the significant config changes between 3.7 and 3.8.
How can I add support for the MPU9250 IMU/compass over SPI?

I have already tried changing:
’#define HAL_INS_DEFAULT HAL_INS_PX4’
’#define HAL_BARO_DEFAULT HAL_BARO_PX4’
’#define HAL_COMPASS_DEFAULT HAL_COMPASS_PX4’

to:
’#define HAL_INS_DEFAULT HAL_INS_MPU9250_SPI’
’#define HAL_BARO_DEFAULT HAL_BARO_PX4’
’#define HAL_COMPASS_DEFAULT HAL_COMPASS_AK8963_MPU9250 '
Thank you.

2

It appears as though there is no communication over SPI at all when using arduplane 3.7, However the IMU works correctly with 3.8 and the above changes.

3

currently the error occurs at initialization, giving the error:
MPU9250: unexpected WHOAMI 0x0

another breadcrumb that seems relevant is that it will try to start a l3gd20 driver, fail and fall into px4_sensor_error(“no l3gd20 found”) unless l3gd20 init code is commented out.

There is no l3gd20 as the mpu9250 is replacing it.