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Topic: MPU 6050 / MPU 9150 Sampling Rate (Read 2511 times) previous topic - next topic


I am trying to set the sampling rate for the accelerometer and the gyroscope.

From the register map (http://www.invensense.com/mems/gyro/documents/RM-MPU-9150A-00.pdf), (page 11 of 60):

Register 25 - Sample Rate Divider

The Sample Rate is generated by dividing the gyroscope output rate by SMPLRT_DIV: Sample Rate = Gyroscope Output Rate / (1 + SMPLRT_DIV) where Gyroscope Output Rate = 8kHz when the DLPF is disabled (DLPF_CFG = 0 or 7), and 1kHz  when the DLPF is enabled (see Register 26).
The accelerometer output rate is 1kHz. This means that for a Sample Rate greater than 1kHz, the same accelerometer sample may be output to the FIFO, DMP, and sensor registers more than once.

In my understanding, if the DLPF (Digital Low Pass Filter) is enabled then both the gyroscope and the accelerometer sample at 1kHz and setting a value of say 4 in register 25 will make the sample rate: 1kHz / (1+4) = 200Hz for BOTH the accelerometer and the gyroscope. Is that correct? Does enabling the DLPF not affect the sampling rate of the accelerometer as it does for the gyroscope

I want to eventually design a digital filter by converting a continuous time filter (using conventional Bode plot techniques) and need to know the sampling rate for the conversion.

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