About NickDR92

Hi For a research project, I am currently trying to read the acceleration data from the BMA280. This chip is used by silabs on there WSTK expansion board. At this moment I'm following a complete procedure to initialize the accelerometer. Perform self test Check if difference from read out of +X en -X is bigger than 800mg (answer: check) Check if difference from read out of +Y en -Y is bigger than 800mg (answer: check) Check if difference from read out of +Z en -Z is bigger than 400mg (answer: check) Soft reset the accelerometer wait 1,5 sec Initialize the accelerometer to my preferences Perform Fast compensation Clear offset register Set offset compensation to X: 0g, Y: 0g, Z:+1g, BW 1% X-axis calibration Y-axis calibration Z-axis calibration Read offset X              my answer: x = -31 mg Read offset Y              my answer:  y = -15 mg Read offset Z             my answer:  z = 0 mg init done The values afterwards are x=+-20mg, y=+-2mg en z=+- -19mg. I expected the values would be x=+-0g, y=+-0g en z=+- -1g when the chip is laying flat on my desk. I convert the acceleration data in this way.     volatile float factor = 0.488; // 8000/2^14 mg/LSB // X-Axis in 0x02-0x03 LSBx = BMA280_read_register(USART1, BMA280_ACCD_X_LSB); LSBx = LSBx >> 2; MSBx = BMA280_read_register(USART1, BMA280_ACCD_X_MSB); tmpx = (uint16_t)((MSBx << 6) | LSBx); acceleration[0] = (float) tmpx * factor;   Can somebody confirm me If this is correct? Or give me the correct init from the accelerometer? Thank you in advance Best Regards Nick ... View more