Limits on Sensor Fused Logs

We are hoping to log sensor fused acc, gyro and mag data simultaneously with NDoF mode.

On iOS with the latest SDK, turning on all three sensor logs triggered the error message:

"MetaWear out of memory, can't perform action. Reset the MetaWear and use no more than 8 log entries"

We can successfully capture any 2 out of 3 sensors (6 logs total). Is there a way to get all three? The docs on sensor fusion (https://mbientlab.com/iosdocs/latest/sensor_fusion.html#corrected-sensor-readings) is not entirely clear on the limitation.

We are also looking for ways to cut down on the amount of the data we have to transfer from MetaWear to iOS. Transfer just takes too long due to BLE and iOS limitations.

Is it the correct understanding that sensor fusion uses accelerometer, magnetometer, and gyro modules to generate logs internally, then the MetaWear board filter and process the internal logs to create the separate corrected acc, gyro, mag data log data?

If that's the case, are the internal logs significantly smaller? Is it possible to perform the post processing within the iOS SDK?

Thanks

Comments

  • If you want to log sensor fusion data, you will be limited to a max of 2 fused outputs. Unless you can show that the corrected imu data is vastly superior to the raw IMU data, then log the raw values instead, in which case you can log from all 3 sensors simultaneously.

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