BHI160, BME280 and BMM150 selftest

[owain-incus]

Hi,

I am working on manufacturing and selftest firmware for our product and want to force BHI160 to run selftests on itself and the attached sensors.

I have followed the example at ...

https://github.com/BoschSensortec/BHy1_driver_and_MCU_solution/blob/master/examples/selftest_example...

but the only meta event I am seeing is BHY_META_EVENT_TYPE_INITIALIZED = 16; I do not see any BHY_META_EVENT_TYPE_SELF_TEST_RESULTS = 15.

Do I have to use special sensortech firmware?
Do I have to do something to enable the selftest events?

Kind Regards,

Owain

[o_o · Accepted solution]

At every boot, BHI160 will initialized each part and will only succesfully boot if each slave answers, so it is guaranteed that communication work. But that is not a true self-test.  Luckily the self-test code for each slave is pre-programmed in the Sensor Hub.

The init function typically boots up the hub directly, which is why you don't get self-test results. to trigger it, this piece of code is the important bit:

	bhy_set_chip_control(0);
	bhy_set_host_interface_control(BHY_HOST_SELFTEST, ENABLE);
	delay_ms(100);
	
	bhy_set_chip_control(1);

At boot it checks the value of the self_test_enable bit, and if true will perform the self-test, this is why you need to stop the CPU and restart it.