Change Log Wednesday April 26, 2017

04-26-2017 Updated usage of Wire.endTransmission after Wire.requestFrom

04-21-2017 Corrected Wire.setClock call in MPU60X0.cpp.

04-09-2017 Added Master Mode Support using elements from Brian Taylor's MPU9250 libray. Master Mode allows support for two MPU9250's on same I2C bus using its capability to have two different addresses. Usage: Establish two instances of the library: 1. Set the FreeIMU objects FreeIMU my3IMU0 = FreeIMU(); FreeIMU my2IMU1 = FreeIMU();

		2. in the setup initialize the 9250s with the correct addresses
			my3IMU0.init(0x68, true);
			my3IMY1.init(0x69, true);
		
		3.When you raw data you will need to make sure you identify the data to the correct IMU object:
			my3IMU0.getRawValues(raw_values0);
			my3IMU1.getRawValues(raw_values1);
			
		4. You will need of course to do the same for calibrated values;
			m3IMU0.getValues(q, val);
			m3IMU1.getValues(q, val);

03-11-2016 Added new Processing GUI based on Multiwii GUI. Hope I am not violating any licenses. If I am please let me know. To use go to setup select whether you have a GPS attached and set any values you want. Click on START button to connect and switch to the FreeIMU tab.

03-05-2017 Added a FreeIMU_serial_2.ino sketch that will send continuous data to the Processing GUI. All other functions functions remain the same. Added a new Processing Gui v6 that works with the serial_2 sketch Additional functions available in serial_2 sketch as well as serial sketch: 'y' - prints only yaw, pitch and roll values 'j' - prints out calibrated values

03-02-2017 Added three sketches that can support WiFi One is for the ESP8266, the second for the ESP32 and the third third for the Microduino Wifi(ESP) module. The 8266 sketch was tested on the LinkNode D1, the 32 sketch on a ESP32 dev board from Onehorse on Tindie. There are also two processing sketches that you can use with the WiFi in the Processing directory. To use you will need to install the ESP8266 Arduino library or the Arduino ESP32 libraries on Github. They give you detailed instructions on installation. For the Microduino ESP module I included a copy of the Arduino WiFiEsp library.
--- For the Microduino you will need to download and flash it with 1.3 AT firmware: http://www.electrodragon.com/w/ESP8266_AT-Command_firmware I included a copy in the extras folder, --- The WiFiEsp library is at (for ref): https://github.com/bportaluri/WiFiEsp

12-09-16 Made the Magnetic Disturbance algorithm optional. If you want to enable uncomment the following line in the FreeIMU.h file:

#define DISABLE_MAGJAM // Uncomment this line to disable the magnetic disturbance

12-08-16 Added a magnectic disturbance algorithm that will detect presence of strong magnetic fields. Algorithm is based on discussion at https://forum.pjrc.com/threads/33902-Prop-Shield-NXPSensorFusion-observations References: Accurate Orientation Estimation Using AHRS under Conditions of Magnetic Distortion http://www.mdpi.com/1424-8220/14/11/20008 and Unscented Kalman filter and Magnetic Angular Rate Update (MARU) for an improved Pedestrian Dead-Reckoning, https://www.researchgate.net/publication/235634565_Unscented_Kalman_filter_and_Magnetic_Angular_Rate_Update_MARU_for_an_improved_Pedestrian_Dead-Reckoning?enrichId=rgreq-3005504c-ee49-416d-9a75-95eca90fb5e5&enrichSource=Y292ZXJQYWdlOzIzNTYzNDU2NTtBUzoxMDIyMTAxMjU5NTkxNzRAMTQwMTM4MDIwMTQ5Ng%3D%3D&el=1_x_2

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12-08-16 Updated code where necessary for updated Pololu libraries.

03-29-16 Added support for the LSM9DS1 IMU using the Sparkfun Library.

02-26-16

1. Added support for the CurieImu with a 5883l magnetometer attached.
2. Tweaked CurieImu settings
3. Fixed Cal_Gui.py so you can calibrate just a accelerometer
4. Modified a FreeIMU_cube_Odo_Exp_v4 processing sketch that works with Processing 3.

02-05-16 Several additional updates had to be to for the 1.6.7 IDE to work nice with the FreeIMU library.

In addition, I implemented and tested the freeimu library with the new Arduino 101 Curie board. To get working I had to make a minor modification to the CurieImu.cpp file so I created a local copy as part of the FreeIMU library :). Additional changes were made to the FreeIMU.h and FreeIMU.cpp files. I added two example files to the CureIMU local library that I tested with the CurieIMU. You will have to use the FreeIMU_cube processing sketch if you are using Processing 3.0 and above. When I have time I will post a video.

01-20-16 Updated several libraries, FreeIMU.cpp/FreeIMU.h, etc to make compatible with Arduino IDE 1.6.7. In addition, sketches should run on all boards except for Arduino 101 which will be hit or miss depending on the IMU configuration. Still working on this.

Also, incorporated pull requests and bug fixes.

12-01-15 Replace LPS331 library by LPS libray for compatibility with ALTIMU10 v3 (LPS331AP) and AltIMU-10 v4 (LPS25H). ------- https://github.com/pololu/lps-arduino ------- Add support for the Dadafruit 10-DOF IMU (L3GD20H / LSM303 / BMP180). ------- Thanks to grezco for incorporating these changes. Added additional code to Extended Kalman Filter example to work with Eigen without need to modify the Teensy board file. Thanks to users over at Teensy forum

10-11-15

Renamed DebugUtils directory to FreeIMUUtils and moved CommunicationUtil.h and .cpp files to this directory. This was done to allow FreeIMU and FreeIMU60XX to coexist without errors.

10-10-15

Added a FreeIMU60XX library. This is essentially the same as the FreeIMU library tailored to fit on the Arduino Uno and supporting only the Invensese 6000, 6050, 9150 and the 9250 MPU. It also now only supports the MS5611 pressure sensor.

Inorder to make it fit the temperature compensation and motion detection routines have been removed.

08-25-15

Added 360 degree Euler angle rotation function. Also fixed an issue with val array out of bounds preventing correct angles being returned when angle functions are returned.

08-24-15

Added support for the MS5637 Pressure Sensor using a slightly modified version of the Freetronics library. All sketches were updated according.

07-24-15

Completed adding support for the LSM9DS0 iNemo IMU. Made use of the Sparkfun LSM9DS0 library. Thanks to the guys at Sparkfun, I owe you guys at SFE a few beers. I did have to make a minor modification to the library to make it callable from the FreeIMU class. Based on initial tests its a pretty impressive little IMU. Staytuned for another video showing the stability of this little board.

07-18-15

In verification of the Kalman code on a DFROBOT 10DOF IMU and with the Arduino Due as well as the Teensy 3.1 I found that I had to change the default values for Q and R with of the Extended Kalman Filter to work with both MPU6050 and DFROBOT IMUs. Unfortunately I just can not tune the EKF for the DFROBOT IMU to get yaw from drifting uncontrollably. Works great with the MPU6050. In addition, found that while the tkjelectronics kalman sketch works with all boards the EKF version does not compile on the Teensy 3.1 without modification to the boards.txt linker options. I can not find the issue that keeps it from compiling. Appears to be a vararg issue. So if any enterprising person that can find the problem or comes up with better tuning values please let me know.

07-11-15 Made available two kalman filters for use with the FreeIMU library. The first is the Kalman implementation by Kristian Lauszus, TKJ Eectronics, http://www.tkjelectronics.com, using his modified sketch that will compare the FreeIMU filter selected to that of the Kalman filter. The Arduino sketch is FreeIMU_KalmanV1.ino. The sketch requires the StandardCplusplus lib - please use the version on my github page as I had to make changes to it to work with the mega and other arduino boards per a issue description from the library.

The second implementaion uses the Kalman class from Picopter - Matthew Watson authored on Apr 29 2013, https://github.com/big5824/Picopter.git. The sketch uses the ArduinoEigen Library and the stlport library which I hava also uploaded so please refresh your download. The sketch for this implementation is FreeIMU_EKF2. I also uploaded a processing sketch from Adafruit (Bunnyrotate.pde) for their AHRS implementation demo. It uses the Saito object loader. I did make a few modifications including getting rid of the bunny and use the Cassini model that comes with Saito library. This I am also uploading.

03-25-15 Incorporated DCM option based on the 9 Degree of Measurement Attitude and Heading Reference System for Sparkfun 9DOF Razor IMU (SEN-10125 and SEN-10736) and SparkFun 9DOF Sensor Stick (SEN-10183, SEN-10321 and SEN-10724), https://github.com/ptrbrtz/razor-9dof-ahrs.git. The DCM, MATH and Razor_AHRS.ino files were combined into a DCM library for use with the FreeIMU library.

DCM implementation was based on the original code (http://code.google.com/p/sf9domahrs/) by Doug Weibel and Jose Julio, based on ArduIMU v1.5 by Jordi Munoz and William Premerlani, Jose Julio. Also used by ArduIMU and Minimu-9.

Additional functions added to get Euler angles directly from the DCM class as well as a function to convert the DCM matrix to quaternions which is used in the example sketch to interface with with existing Processing sketches.

An example file has been created to show the DCM implementation with euler angle output. Use existing Serial sketches for use with processing. No other changes are needed.

To use the DCM option set MARG = 4. Remember that using a Magnetometer will give you better results than not when using this implementation of DCM. It will work with a 6DOF but you may not have the best results. You will also have to tune the proportional and integral gains for the IMU you select. I have only tested and tuned the gains for the Microduio 10DOF IMU that I used to test the changes.

01-09-15 Updated xbee-arduino library to add new function: setAPImode(MODE). Where MODE would be set equal to 1 or 2 to correspond to the API mode that you selected for you Xbees. Defaults to API Mode 2.

01-01-15 Merged pull request by Mauro Mombelli who fixed AHRS.h for readability and merged ARHSupdateIMU with AHRSupdate. Updated FreeIMU.h accordingly.

11-28-14 Have incorporated the XBee-Arduino library by Andrew Rapp into an example sketch (FreeIMU_serial_ARM_CPU_XBEE.ino). Did make a modification to it so that it would send packets without escapes. So please use the one in the library folder otherwise it will not work. Incorporated the Digi Xbee Java Library into the processing GUI (FreeIMU_cube_Odo_Exp_Digi2) in the Experimental folder. This code has only been tested with the Mega with XBee 900HPs.

NOTE: To use the Xbee-Arduino with its examples skecthes you will need to edit the Xbee.h file and set ATAP=2 (Escpaes sent), currently set to ATAP=1 (No Escapes).

11-19-14 Combined running average filter and simple moving average filter into the AP_Filter library.

Added a capability to the Arduino serial sketch to load a permanent GPS config file from a attached I2C eeprom. For my setup default baud is 57600.

11-13-14 Added gyro_sensitivity as a variable to be defined in the sensors settings area of the FreeIMU.cpp file.

Re-worked code for defining sensor alignment so it is defined once in the FreeIMU.h file. Allows getQ_simple function to be used for all 9dof IMUs. Also simplies calling of AHRS functions.

11-08-14 Fixed getQ_simple function to calculate quaternions correctly from yaw, pitch and roll. Modified the function so it can be used to improve convergence when IMU transitions from motion to zero motion. Updated examples to include moving average filter. Serial sketch serial_ARM_cpu can be used universally and output motion detect to the v3 processing sketch in the experimental folder. Still have to make changes to a couple of the other sketches.

11-05-14 Thanks goes to duguyiqiu for pointing out that the Arduino Due Freq was not printing correctly. As a result I found that the legacy code did not address the I2C bus speed for the Due or the Mega 2560 to 400hz. This is fixed with this update.

11-04-14 Minor update. Moved motion detect algorithm to FreeIMU library proper. Created FreeIMU_cube_Odo_Exp_v3.pde to take motion detect from library.

10-25-14 Fixed severaly bugs that would cause the new AHRS filter to crash on compile. Jitting is still there and its a lot of fun watching the algorithm work with the default settings for the MPU9250. Have fun tweaking the settings.

10-24-14 Implemented a third version of the Madgwick filter (Gradient Descent). This version is directly from his original paper. Beta and Zeta have been left at their default values in the paper.

10-19-14 Several updates/corrections made to library: Fixed APM 2.5 axis alignment, deleted a 3g library that was not there, more tweaks to beta terms, uploaded missing TinyGPS++ library and moved Baudrate setting to beginning of sketches.

Incorporated MPL3115A2 pressure sensor support by Mario Cannistra (https://github.com/mariocannistra) as well as an example using a MPU-9250 using the MPL3115A2.

10-12-14 Updated library for support to APM 2.5 (Arduimu). This change should also work on the APM 2.6 board as well. MS5611 SPI library added from Ardupilot library (saved alot of time - thanks guys). Put back iCompass module for aligned axis. Had typo - now fixed so put it back in.

This SPI code for the MS5611 is based on the example sketch by JP B, "APM 2.6 and MPU6000 gyro - any custom firmware out there for this?" found at https://groups.google.com/forum/#!topic/diyrovers/thIohPCNyZA. Also see http://forum.arduino.cc/index.php?PHPSESSID=6mia4mslt5dalc1fi4ad8rl2g1&topic=125623.0

10-03-14 Updated FreeIMU.cpp to allow easier access to change accelerometer/gyro/magneter default range settings to match description in wiki page

09-22-14

Changed LSM303 library default sampling rate to 100hz for accel and magnetometer to adjust for use with Teensy 3.1

Updated (int) to (int16_t) in lps331 library for getTemperatureRaw.

FreeIMU examples updated accordingly based on compass averaging change.

09-20-14

Deleted iCompass and RunningAverage from FreeIMU. Compass averaging is done in the Processing sketch using Yarmartino compass averaging method which is more address issue of discontinuity at 0/360 degrees. Tests on the Altimu10 v3 are much more stable. The processing code was adapted from Christopher Baker's code at https://github.com/SAIC-ATS/Algorithms.git. Will leave runningaveage library in case anyone wishes to use it for other reasons.

iCompass deleted as tilt compensation was not working properly. Tilt compensation is still done from within FreeIMU.cpp using a different method.

FreeIMU_serial.ino updated to reflect changes to implementation of altidue complimentary filter from within the library as opposed to calling from the serial sketch.

Remaining sketches are in the process of being updated.

09-12-14 - Updated tuning for Altimu10v3, MPU9250 breakout board from Innvense, and FreeIMUv0.4.3.

09-03-14 - As a result of a conversation with Dan Barzilay did a little more research and determined that using Seb Madgwicks MARG gradient descent filter would provide an improvement to the drifting that I was still seeing. Preliminary tests with the FreeIMU v4 board were promising as well as additional testing with several other boards. As a result the MadgwickAHRS code was added to FreeIMU library directly from the X-IO website with some minor coding changes to allow you to select either or of the implementations.

Please consider this a better release as still have some additional testing to perform.

See video: http://youtu.be/VCxzleg9KA4 Refs: http://www.hindawi.com/journals/ijdsn/2014/864768/ http://code.google.com/p/uav-helicoptor-ece4007/wiki/MadgwickAHRS

08-29-14 - incorporated changes proposed by Dan Barzilay which incorporates the Altitude Complimentary filter and the Heading calcs that was in the Procressing sketch directly into the library.

Arduino serial sketches were updated to output the heading and altimeter accordingly. As a result of the changes the Processing sketch was simplified and the changes incorporated into the FreeIMU_cube_Odo_Exp_v2 Gui in the experimental folder.

Additional changes to the FreeIMU_cube_Odo Gui will be made shortly.

My thanks to Dan for incorporating these changes.

08-22-14 Added same serial options in the Yaw-Pitch-Roll processing sketch as available with the processing GUI.

08-21-14 Update all Processing sketches with additional delay.

08-20-14 Added delay to processing sketch before serial read loop in set-up. Uploaded Processing 2.0b7 which works with the GUIs, no issue.

08-18-14 Reload of Freeimu.cpp, freeimu.h, calibration.h, freeimu_serial.ino and freeimu calib. Tommasso report errors but I could not duplicate with my test versions so i am re uploading.

06-20-14 -------- Based on Kris Winer's work on the MPU-9250 and the AK8963 I was able to create a basic AK8963 library modeled after that of the AK8975 library from Jeff Rowberg. This was then incorporated into FreeIMU library.

04-19-14 ------- Added support for GPS in Arduino and Processing Sketch using TinyGPS++ and AltSerialSoft libraries. ------- TinyGPS++ : http://arduiniana.org/libraries/tinygpsplus/ ------- AltSoftwareSerial : https://www.pjrc.com/teensy/td_libs_AltSoftSerial.html

04-09-14 1. Deleted Fabio's implementation of the AHRS filter and inserted the complete version from Seb Madgwick's X-io website. Seemed to fix the mag issue dramatically. 2. Put median filter back in using a 5 point filter instead of 7 3. Fixed zero gyro issue when using the ADXL345

04-07-14 Added initGyros() routing from Ardupilot as well as filtering library so a median filter can be used for ADXL345 accelerometer. Code added to allow multiple board configuration Kp/Ki gains. Added ADXL345 temp cal for the DFROBOT board. Noticed I have to fix GUI for when you don't have a magnetometer on board. Next step drift correction.

03-05-14 Uploaded automated calibration code and methodology using Seb Madgwick calibration rig. His original paper is also posted on construction.

03-04-14 Fixed issue with increased drift when magnetometer enabled by updating Fabio's code to the Madgwick code posted on his X-IO website.

03-02-14

1. Default to temp correction off.
2. Updating code as temp correction only applicable to MPU-6050 or 9150 at this point.
3. Clarified GenMPU6050 and DFROBOT defines
4. Added code for BMP085 altimeter   02-27-14 Fixed code issues with generic MPU6050 output for raw values. 

10-27-2013 1. Modified incorporate temperature correction for gyro and accelerometer 2. Corrected AVR to AVR_ATmega128 3. Added call to get temperature from MPU-6050 in getRawValues 4. 1D Kalman Filter on q-values in sketch

10-29-2013 Corrected temp coefficient array for temp  
11-01-2013 Added new inverse sqrt code obtained from articles: http://pizer.wordpress.com/2008/10/12/fast-inverse-square-root/ and http://www.diydrones.com/forum/topics/madgwick-imu-ahrs-and-fast-inverse-square-root  
11-05-13 1. Add code to reset MPU-6050 on start-up, implemented in the Arduino sketch as well as option to manually reset in processing sketch. 2. Added LPF code line, currently set to MPU60X0_DLPF_BW_42  
11-23-13 1. Changed twoKidef from 0.1 to 0.0f -12-12 => twoKiDef changed from 0f to 0.0025f based on article in DIYDrones 2. Added bypass caps (0.1 and 0.01 ceramic caps on the power pins of the freeIMU 2a. Added a 10 uF tantalum on the power bus 3. Yaw drift stabilized very nicely 4. Updated processing sketch to calculate heading and display based on the freescale application note and as implemented: http://diydrones.com/profiles/blogs/tiltcompensated-heading 5. update RESET function to zero out initial values  
12-06-13 1. added LSM303D Polulo board instead of calculating heading from FreeIMU 2. added option to turn on/off temp correction, temp_corr_on 3. added variable to set temperature break where calibration turns off, temp_break, note: temp_break in units directly from MPU-6050  
01-02-14 to 01-05-14 1. Recalibrated 6050 using Madgewick automated calibration rig - see paper 2. Corrected temperature calibration coefficients to ensure that gyros are zeroed for whole temp range when at rest - deleted necessary to run zerogyro routine. 3. Acceleration coefficients adjusted so Ax = 0, Ay = 0 and Az = 1g when at rest 4. Had to tune Ki to reduce drift - now set to 0.165 5. Changed Kp to 1.0 - drift almost zero  
01-08-14 1. Completed coding ZARA ZUPT for Zero velocity detemination - added code to the processing sketch  
01-09-14 1. Added a Reset Quaternion matrix only - option 2 in the sketch - to allow reset of matrix after rapid movement.  
1-20-14 Summary of Processing sketch

1. updated to incorporate Altitude-Accelerometer complimentary filter
2. motion detection indicator based on Zara-Zupt
3. read additional fields from Arduino sketch
4. Heading stability routine for LSM303 heading.
5. Reset MPU-6050/Quaternion matrix by sending serial commands 1 or 2 respectfully.