BMI270 accelerometer range do NOT change

[Anatol]

Whatever is written to the register 0x41 ACC_RANGE I always get 1G readings around 4100 LSB so 8G range (default). 

The register was set either by API configuration like:

config.cfg.acc.range = BMI2_ACC_RANGE_2G;

or directly by code:

const uint8_t byte0x03 = 0x03; // 16G range
bmi2_set_regs(0x41, &byte0x03, 1, &bmi2);

- no difference. The register is read by:

bmi2_get_regs(0x41, reg_data, 1, &bmi2);
Serial.print("Read 0x41 ACC_RANGE HEX (0x00 = 2g) = "); Serial.print(reg_data[0], HEX); 

after accelerometer readings and it corresponds to what I write, like 0x00, 0x03, so no way 0x41 ACC_RANGE is reset to default somewhere in code. But raw readings for accelerometer data for 1G never change. Tried two BMI270 boards - no difference.

Any ideas how can it be possible?

[BSTRobin · Accepted solution]

Hi Anatol,

The example on GitHub works well. I think you can refer to the example program to check whether each step is successful, and then check whether the acceleration data is normal.
https://github.com/BoschSensortec/BMI270-Sensor-API

[Anatol · Accepted solution]

Hi BSTRobin.

I  use Arduino IDE, API you pointed out does not work there as I understand, so I used BMI270_COINES_SPI_Accel_Gyro 

https://community.bosch-sensortec.com/varuj77995/attachments/varuj77995/bst_community-mems-forum/474...

It didn't compile at first so I had to make many changes to get it working, had to adopt to I2C bus and ESP32 controller. But as I understand, COINES is essentially the same code as the library in your link, just adopted for Arduino, right?  It is what I use to communicate with BMI270.

Oops! I just tried my previous code described above and it really shows correct acceleration, so it is after my later implementation of it into a more complicated code when problem starts. Great, now I have a starting point. Thanks very much for a clue.

[BSTRobin]

Hi Anatol,

Our reference code sensor API was written in C language, which is different from Arduino. However, it could be migrated to different platform, and the Coins interface can be replaced with the interface of Arduino platform.

[Anatol]

Yes, I did it already. But I'm still puzzled how can readings from acc_range register be not in accordance with the actual LSB/g value.