10DOF FreeIMU port for FreeIMU v4 board and GY-86. This library was modified extensively to specifically suit the Mbed platform. Used threads and interrupts to achieve async mode.

Dependencies:   HMC58X3 AK8963 MS561101BA MODI2C MPU9250

Dependents:   MTQuadControl FreeIMU_serial FreeIMU_demo

Port of FreeIMU library from Arduino to Mbed

10DOF FreeIMU port for FreeIMU v4 board and GY-86. This library was modified extensively to specifically suit the Mbed platform. Maximum sampling rate of 500hz can be achieved using this library.

Improvements

Sensor fusion algorithm fast initialization

This library implements the ARHS hot start algorithm, meaning that you can get accurate readings seconds after the algorithm is started, much faster than the Arduino version, where outputs slowly converge to the correct value in about a minute.

Caching

Sensors are read at their maximum output rates. Read values are cached hence multiple consecutive queries will not cause multiple reads.

Fully async

Acc & Gyro reads are performed via timer interrupts. Magnetometer and barometer are read by RTOS thread. No interfering with main program logic.

Usage

Declare a global FreeIMU object like the one below. There should only be one FreeIMU instance existing at a time.

#include "mbed.h"
#include "FreeIMU.h"
FreeIMU imu;

int main(){
    imu.init(true);
}

Then, anywhere in the code, you may call imu.getQ(q) to get the quarternion, where q is an array of 4 floats representing the quarternion structure.

You are recommended to call getQ frequently to keep the filter updated. However, the frequency should not exceed 500hz to avoid redundant calculation. One way to do this is by using the RtosTimer:

void getIMUdata(void const *);     //method definition

//in main
RtosTimer IMUTimer(getIMUdata, osTimerPeriodic, (void *)NULL);
IMUTimer.start(2);     //1 / 2ms = 500hz

//getIMUdata function
void getIMUdata(void const *dummy){
    imu.getQ(NULL);
}

History

change to I2C 1 default tip

2018-04-18, by tyftyftyf [Wed, 18 Apr 2018 20:25:07 +0000] rev 29

change to I2C 1


parameter tuning

2018-03-29, by tyftyftyf [Thu, 29 Mar 2018 22:35:45 +0000] rev 28

parameter tuning


wip

2018-03-29, by tyftyftyf [Thu, 29 Mar 2018 22:07:11 +0000] rev 27

wip


jhgfdsa

2018-03-28, by tyftyftyf [Wed, 28 Mar 2018 22:17:32 +0000] rev 26

jhgfdsa


calibrate

2018-03-28, by tyftyftyf [Wed, 28 Mar 2018 22:07:16 +0000] rev 25

calibrate


wip

2018-03-28, by tyftyftyf [Wed, 28 Mar 2018 22:00:32 +0000] rev 24

wip


wip

2018-03-28, by tyftyftyf [Wed, 28 Mar 2018 21:48:57 +0000] rev 23

wip


wip

2018-03-28, by tyftyftyf [Wed, 28 Mar 2018 21:34:16 +0000] rev 22

wip


fix build error

2018-03-28, by tyftyftyf [Wed, 28 Mar 2018 21:23:43 +0000] rev 21

fix build error


wip

2018-03-28, by tyftyftyf [Wed, 28 Mar 2018 21:07:02 +0000] rev 20

wip