BMI270 API (bme2.c) FIFO Bug

[bront]

I'm using the BMI270 API found here with a known working hardware platform. In this configuration I'm using the FIFO in header-less mode with both Accelerometr and Gyroscope data being collected. My code is based on the example of this type and I have an issue where the last accelerometer sample is not being retrieved by the bmi2_extract_accel function from the FIFO frame. The extraction function repeatedly calls the check_dummy_frame function shown below. 37 bytes are read from the FIFO with the first being a dummy. When extracting the acceleration the the data_index is set to 31 on the 3rd acceleration sample. This sample resides in bytes 31:36 (6 bytes). The logic in the below function below fails but should instead say if(((*data_index) + 6) <= fifo->length)

[BSTRobin]

Hi bront,

As you enable accel and gyro, set the FIFO in header-less mode, FIFO data length should be 6 bytes every frame, total FIFO length should be an integer multiple of 6 bytes. FIFO length 37 didn't match it.
With BMI270 github code, I run FIFO watermark interrupt code and get correct result for your reference. https://github.com/BoschSensortec/BMI270-Sensor-API

[bront]

Robin,

Which example are you using? My code is based off of the FIFO Headerless Watermark example (https://github.com/BoschSensortec/BMI270-Sensor-API/blob/master/bmi270_examples/fifo_watermark_heade...). The numbers in this example wouldn't yield 100 samples of each sensor. The image below is from the linked example, (6 + 6) * 54  = 648 not 650. Is this some sort of padding to make the driver work correctly?

[BSTRobin]

Hi bront,

Previous attached code refer both github FIFO header and headerless example code, some modifications have been made based on the example code, like ODR, using hardware interrupt.