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CC2541 SensorTag Yaw calculation

Hello,

I understand that it is not possible to get yaw measurements from the accelerometer, only pitch and roll (x and y axis).

Is there any sensortag api which allows me to get yaw or heading information from the sensortag.  I believe one way is to perform sensor fusion, but with the gyroscope output a 1/sec, this would not be sufficient.

Appreciate any feedback. 

Thanks,

Winston

  • I think that should be 1000/sec as the minimum sampling rate 8000/sec as the max. http://www.farnell.com/datasheets/887153.pdf

    Also from the Datasheet:

    • X-, Y-, Z-Axis angular rate sensors (gyros) on one integrated circuit

    • Digital-output temperature sensor

    • 6-axis motion processing capability using secondary I2C interface to directly connect to a digital 3-

      axis third-party accelerometer 

  • Hello Greenja,

    Thank you for the reply.  The Sensortag looks like it is using the Invensense chip (IMU-3000).  From reading another post, I don't think there is a way to update the gyroscope sampling to less than 1/second.  

    Can you advise as to whether in IOS, there is a way to set the characteristic for the gyroscope sensor to update to less than 1/second, say 100/second?  The chip is capable but I do not think there is any way to set it.

    Thanks,

    Winston

  • This sounds like it would have to be done in the firmware on the SensorTag.  There are default sampling rates that are #define statements in the code.  You could change these to variables and write new characteristic values to them from iOS, but you would first have to modify the SensorTag code.

    Thanks,