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    1 khz data rate

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    1 khz data rate

    I'm designing a camera for a bio-physics group.  The camera has a hexagonal array of photodiodes to emulate fly vision.  I need at least a gyro and an accelerometer and magnetometer might be useful.

    I need the gyro data at 1000 samples per second, and need to sync the data with the photodiode ADC sampling rate.

    Have been looking at BMX055, BMI270, BMI160 and BMX160 datasheets.

    The BMI/BMX 160 don't have an ODR rate selection of 1 KHz; the closest is 800 or 1600 Hz.  But, can I just read the registers directly without using the FIFO?

    I think the BMI270 is similar.  The BMI/BMX 055 does have a 1 ms selection for ODR, but I don't see that I can sync this to my photodiode ADC system.

    Suggestions welcome!  I'm an electronics engineer with plenty of data acquisition experience, but this is my first time using an IMU.

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    Community Moderator
    Community Moderator

    Re: 1 khz data rate

    MEMS gyroscopes by design cannot be synchronized with other sources, because the device operates by moving the internal structure at its resonant frequency, and the sampling must be synchronized with the oscillation of the part.

    In BMI055/BMX055/BMI085/BMI088/BNO055/BMF055, the gyroscope can operate at 1kHz frequency, and you could use the data ready as a trigger for your ADC sampling.

    In BMI160/BMX160/BMI270, the sensor has a sensortime mechanism that allows you to precisely determine the timestamp and age of the sample, and relate it to the timestamp of your host MCU. Also, the interrupts pins can also be configured as an input, and the FIFO can capture a snapshot of the INT pin level when new data is sampled.