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    BMX160 - Setting the correct ODR

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    Senior Member

    BMX160 - Setting the correct ODR

    Hi, I suppose that this is a very simple question 🙂

    I there any reason to set higher ODR that the frequency of sensor reading?

    For example, in my code I have set the ODR for both accel and gyro at 800Hz but I actually read the sensors with a frequency of 100Hz. Is there any reason to have the ODR = 800Hz (or higher) or should I decrease it to 100Hz?

    sensor.accel_cfg.odr = BMI160_ACCEL_ODR_800HZ;     
      sensor.accel_cfg.range = BMI160_ACCEL_RANGE_2G;    
      sensor.accel_cfg.bw = BMI160_ACCEL_BW_NORMAL_AVG4; 
      sensor.accel_cfg.power = BMI160_ACCEL_NORMAL_MODE; 
    
      sensor.gyro_cfg.odr = BMI160_GYRO_ODR_800HZ;        
      sensor.gyro_cfg.range = BMI160_GYRO_RANGE_2000_DPS; 
      sensor.gyro_cfg.bw = BMI160_GYRO_BW_NORMAL_MODE;    
      sensor.gyro_cfg.power = BMI160_GYRO_NORMAL_MODE;    

    Thanks in advance 

    Nick

    3 REPLIES 3
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    Community Moderator

    Re: BMX160 - Setting the correct ODR

    Hi,

    Thanks for your inquiry.

    If you set BMX160 both accel and gyro ODR to 100Hz, then the 3dB cutoff frequency for accel and gyro will be 40.5Hz and 39.9Hz respectively according to BMX160 datasheet Table 13 and Table 15. If your physical motion signal maximum frequency is 50Hz for example coming from the vibration, then 100Hz ODR for BMX160 accel and gyro will not be fast enough to measure and duplicate the motion signal. You need to increase the ODR to have the bandwidth that is higher than 50Hz.

    Thanks.

    Highlighted
    Senior Member

    Re: BMX160 - Setting the correct ODR

    Thank you for your great responce!! So in order to measure with a frequency of 100Hz I have to set at least 400Hz ODR for both Accel and Gyro right?

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    Community Moderator

    Re: BMX160 - Setting the correct ODR

    Hi,

    Yes, you should set BMX160 accel and gyro ODR to 400Hz or higher in order to measure 100Hz signal, because the 3dB cutoff frequency of accel and gyro is higher than 100Hz when at 400Hz ODR.

    Thanks.

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