bolderflight / invensense-imu Goto Github PK

This is great source for MPU9255 but I found error and unstability of sensor data in readsensor() when I printed raw data:
// display the data
Serial.print(_axcounts);
Serial.print(" \t");
Serial.print(_aycounts);
Serial.print(" \t");
Serial.print(_azcounts);
Serial.print(" \t");
Serial.print(_gxcounts);
Serial.print(" \t");
Serial.print(_gycounts);
Serial.print(" \t");
Serial.print(_gzcounts);
Serial.print(" \t");
Serial.print(_hxcounts);
Serial.print(" \t");
Serial.print(_hycounts);
Serial.print(" \t");
Serial.print(_hzcounts);
Serial.print(" \t");
Serial.println(_tcounts);
raw data printed like this:
30827 -59 -32145 32763 48 -22 27 10 32730 -31909
30825 32703 618 -5 -32702 32747 27 10 32730 859
30825 32703 618 -5 -32702 32747 27 10 32730 859
30813 -61 -32168 32767 54 -16 27 10 32730 856
30813 -61 -32168 32767 54 -16 27 10 32730 856
30836 -57 -32152 -1 -4 -4 27 10 32730 858
30836 -57 -32152 -1 -4 -4 27 10 32730 858

I also recommend custom SPI definition using:
int MPU9250::begin(uint8_t CLKPIN,uint8_t SOPIN,uint8_t SIPIN,uint8_t _csPIN)
// setting CS pin to output
pinMode(_csPin,OUTPUT);
// setting CS pin high
digitalWrite(_csPin,HIGH);
// setting SPI SO pin to output
pinMode(SOPIN,OUTPUT);
// setting SPI SI pin to input
pinMode(SIPIN,INPUT);
// setting SPI CLK pin to input
pinMode(CLKPIN,INPUT);
// begin SPI communication
// _spi->begin();
_spi->begin(CLKPIN,SOPIN,SIPIN,_csPIN);////SPI.begin(int8_t sck=SCK, int8_t miso=MISO, int8_t mosi=MOSI, int8_t ss=-1);

Hi there,

I have an issue with a project i'm working on.

I have an MPU-9250 and SD Card Module (With a compatible SanDisk 16GB SD Card) connected to an official Arduino UNO board.

I want to be able to record and store the data at a 1KHz sample rate. I believe two issues are perhaps the limitation of bolderflight package, as well as myself using print to read/write to the data, and not storing binary and using a buffer. If anyone could look into this that would be amazing, I'll be very active in checking this thread.

Thank you,

I've attached the file of code I've currently been using.
Arduino Example Issue.pdf

Hello, anyone here tried to use this library coordinate system to get working quaternion with madwick? I have seen this implementation, but it seems that it uses NED reference frame. How can i convert your reference system to NED?

mFilterMadwick.update( elapsed, acceleration.x, acceleration.y, acceleration.z, gyroCalibrated.x, gyroCalibrated.y, gyroCalibrated.z, mCompassCalibrated.x, mCompassCalibrated.y, mCompassCalibrated.z );

Update gyro bias over time. Detect and compensate for magnetometer disturbances.

Hi, i want to print data with specific frequency, so i want to use Interrupt when new data is available then print, but use example sketch Interrupt_SPI and change SPI to I2C then upload sketch serialport is not anything print, i think the attachInterrupt is not work, below is my sketch code.

/*
Interrupt_SPI.ino
Brian R Taylor
[email protected]


```Copyright (c) 2017 Bolder Flight Systems

Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
and associated documentation files (the "Software"), to deal in the Software without restriction, 
including without limitation the rights to use, copy, modify, merge, publish, distribute, 
sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or 
substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include "MPU9250.h"

// an MPU9250 object with the MPU-9250 sensor on SPI bus 0 and chip select pin 10
MPU9250 IMU(Wire,0x68);
int status;

void setup() {
  // serial to display data
  Serial.begin(115200);
  while(!Serial) {}

  // start communication with IMU 
  status = IMU.begin();
  if (status < 0) {
    Serial.println("IMU initialization unsuccessful");
    Serial.println("Check IMU wiring or try cycling power");
    Serial.print("Status: ");
    Serial.println(status);
    while(1) {}
  }
  // setting DLPF bandwidth to 20 Hz
  IMU.setDlpfBandwidth(MPU9250::DLPF_BANDWIDTH_20HZ);
  // setting SRD to 19 for a 50 Hz update rate
  IMU.setSrd(19);
  // enabling the data ready interrupt
  IMU.enableDataReadyInterrupt();
  // attaching the interrupt to microcontroller pin 1
  pinMode(1,INPUT);
  attachInterrupt(1,getIMU,RISING);
}

void loop() {}

void getIMU(){ 
  // read the sensor
  IMU.readSensor();
  // display the data
  Serial.print(IMU.getAccelX_mss(),6);
  Serial.print("\t");
  Serial.print(IMU.getAccelY_mss(),6);
  Serial.print("\t");
  Serial.print(IMU.getAccelZ_mss(),6);
  Serial.print("\t");
  Serial.print(IMU.getGyroX_rads(),6);
  Serial.print("\t");
  Serial.print(IMU.getGyroY_rads(),6);
  Serial.print("\t");
  Serial.print(IMU.getGyroZ_rads(),6);
  Serial.print("\t");
  Serial.print(IMU.getMagX_uT(),6);
  Serial.print("\t");
  Serial.print(IMU.getMagY_uT(),6);
  Serial.print("\t");
  Serial.print(IMU.getMagZ_uT(),6);
  Serial.print("\t");
  Serial.println(IMU.getTemperature_C(),6);
}  

Hello,

Thank you all for the information on this topic.

I have modified the advanced I2C to add a filter to stabilize the data and wrote test code to graph each axis (one program per axis per reading) in real time for testing. I've found that my Accelerometer readings are reading the Gyro (it is still displaying with the Accelerometer units) and my Gyro is reading acceleration in radians.

My functions are correct (I did not put the wrong one in). I am using an Arduino Uno with a sparkfun MPU-9250. I believe this has something to do with the header file, but I am not experienced enough to identify what I would need to interchange. Can I get some help on this?

Let me know what I can provide to be helpful.

Thank you,
Nick

Starting with the example script Interrupt_SPI, if I change the SRD value to something up to 34, everything goes smoothly. However, setting it to 35 or higher causes the magnetometer readings to freeze (i.e., the rest of the readings change, but not the magnetometer ones).

Arduino --> MPU9250
5V --> VCC
GND --> GND
A4 --> SDA
A5 --> SCL

IMU initialization unsuccessful
Check IMU wiring or try cycling power
Status: -1

Sensor recognized in the I2C scanner

Hi Brian.
I am trying to incorporate a function to return the raw data in counts and getting weird results:

1550104011431,1550104013211,220550,1550104015131,41,40,28.28
1550104011431,1550104013211,220550,1550104015131,41,40,28.28

just a couple of samples. Its suppose to represent ax, ay, az, gx, gy, gz, tempC.

Tried it on three different 9250 sensors with the same results. The advanced_i2c function works fine. Here is the function I am using:

int MPU9250::readSensorCounts(int16_t* rawValues)
{
    _useSPIHS = true; // use the high speed SPI for data readout

  // grab the data from the MPU9250
  if (readRegisters(ACCEL_OUT, 21, _buffer) < 0) {
    return -1;
  }
    rawValues[0] = (((int16_t)_buffer[0]) << 8) | _buffer[1];  // combine into 16 bit values
    rawValues[1] = (((int16_t)_buffer[2]) << 8) | _buffer[3];
    rawValues[2] = (((int16_t)_buffer[4]) << 8) | _buffer[5];

    rawValues[3] = (((int16_t)_buffer[8]) << 8) | _buffer[9];
    rawValues[4] = (((int16_t)_buffer[10]) << 8) | _buffer[11];
    rawValues[5] = (((int16_t)_buffer[12]) << 8) | _buffer[13];
	
	rawValues[6] = (((int16_t)_buffer[15]) << 8) | _buffer[14];
	rawValues[7] = (((int16_t)_buffer[17]) << 8) | _buffer[16];
	rawValues[8] = (((int16_t)_buffer[19]) << 8) | _buffer[18];
    
    rawValues[9] = (((int16_t)_buffer[6]) << 8) | _buffer[7];
    
  return 1;
}

Don't know what I am missing here.

Thanks
Mike

Hi, I'm using the library with the ESP32 and it works fine for a few minutes but then it only returns -1 and I have to restart the program. I tried the basic and the advanced i2c example as well. Do you have any suggestion what could be the problem? Or if this is unavoidable is there a way to restart the imu faster? Because right now the begin function does calibration and everything which takes a couple seconds and I want it to go back reading data as fast as possible. Thanks!

Update gyro and accel calibration routines based on Allan Variance data. Output variance, standard deviation, and write bias data to MPU-9250 internal memory.

Does this library use Kalman filter or any other similar algorithms to get more accurate results from the mpu?

Hi , thanks for the great job you doing my problem is I'm getting wrong value for heading angle and I,m using your library and calibration method to calculate the headeing so can you help me?
thanks

When trying to compile the example Basic_SPI for the Arduino Nano or the Arduino Uno boards, I get the error
Global variables use 5368 bytes (262%) of dynamic memory, leaving -3320 bytes for local variables. Maximum is 2048 bytes.

So, is this library not compatible with these boards? In that case, it should be mentioned in the docs.

Edit: the FIFO implemented in the library takes up a lot of space. If the FIFO is removed, everything runs just fine (except for the FIFO related functions, of course). Maybe the FIFO could be allocated dynamically, with a warning that it should only be used by high end boards, such as the Due.

I tried using this MPU9250 library on my MPU6050 because I found this library to be simpler than the ones used for the MPU6050. However it didn't work, though some people said it would.

So, is there anyway to use this library on MPU6050?
Thank you

Is it works? It's every time show me that bias is 0, and scale is 1. But i can read peak 10.7mss on X and min -9.0 or another => real bias ~ -0.9. I checked sourses, but i can't find something wrong.

Hi all,

i am using MPU9250 with an arduino nano and arduino IDE 1.8.9.
When I'm trying to use the BASIC_I2C sketch there is an error with status -5...

IMU initialization unsuccessful
Check IMU wiring or try cycling power
Status: -5

I have checked the error in the MPU9250.cpp:
// check the WHO AM I byte, expected value is 0x71 (decimal 113) or 0x73 (decimal 115)
if((whoAmI() != 113)&&(whoAmI() != 115)){
return -5;
}

But i don't know how to deal with this error and to run the sketch properly..
I'm happy about your advice!

I am trying to compile Basic_I2C and am receiving the following error

No Matching function for call to 'MPU9250_::MPU9250_(TwoWire&, int)'

I am using Arduino uno, Arduino IDE 1.8.7 , I installed via the library manager and the IDE installed it for me. I opened the sketch via the examples menu

Fix Calibration routines changing the SRD

During calibration, the samples from the magnetometer are corrected using the scales and biases already stored.

e.g.: line 897:

_hxfilt = (_hxfilt * ((float)_coeff - 1) + (getMagX_uT() / _hxs + _hxb)) / ((float)_coeff);

This results in the new biases implicitly being relative to the old ones (which breaks them). A way to test it is to calibrate twice on a row, which results in different values.

I think the same line should be:

_hxfilt = (_hxfilt * ((float)_coeff - 1) + getMagX_uT()) / ((float)_coeff);

instead.

Amazing lib btw :)

When i try to calibrate the accelerometer i call the function for each axis and when i show the results all of the biases are 0 and the scale for each one is 1. Is that normal?

CALIB Gyro -- dont move until I say stop!!! done!
X: 0.004778
Y: 0.019271
Z: -0.003822
Gyro calib done
********** ACC calib **************
Enter when ready for dir 1 X+..
Enter when ready for dir 2 X-..
Enter when ready for dir 3 Y+..
Enter when ready for dir 4 Y-..
Enter when ready for dir 5 Z+..
Enter when ready for dir 6 Z-..
Acc calib done
Vals:
X: 0.000000/1.000000 (bias/scale)
Y: 0.000000/1.000000 (bias/scale)
Z: 0.000000/1.000000 (bias/scale)
CALIB MAG -- move in figure 8s until I say stop!!! done!
X: 28.451765/0.883743
Y: 47.327587/1.067171
Z: -51.208195/1.073661

Code used:

Serial.println(F("********** ACC calib **************"));

char * dirs[6] = { "X+", "X-", "Y+", "Y-", "Z+", "Z-"};

for (uint8_t i = 0; i < 6; i++) {
Serial.print(F("Enter when ready for dir "));
Serial.print((int)(i + 1));
Serial.print(' ');
Serial.print(dirs[i]);
while (! Serial.available() ) {
delay(10);
}

while (Serial.available()) {
  Serial.read();
  delay(5);
  Serial.print('.');
}
Serial.println();
IMU.calibrateAccel();

}

Serial.println(F("Acc calib done"));

Serial.println(F("Vals: "));

Serial.print(F("X: "));
Serial.print(IMU.getAccelBiasX_mss(), 6);
Serial.print('/');
Serial.println(IMU.getAccelScaleFactorX(), 6);

Serial.print(F("Y: "));
Serial.print(IMU.getAccelBiasY_mss(), 6);
Serial.print('/');
Serial.println(IMU.getAccelScaleFactorY(), 6);

Serial.print(F("Z: "));
Serial.print(IMU.getAccelBiasZ_mss(), 6);
Serial.print('/');
Serial.println(IMU.getAccelScaleFactorZ(), 6);

Hi,

Thanks for the library! Well done and very robust and easy to debug code.

I am having the following problem regarding the Sensor Calibration routines, all of them (calibrateGyro(), calibrateAccel(), calibrateMag()).
In the beginning of each of them, we set the SRD to be 19 such that we have a frequency of 50 Hz, or a sample coming every 20ms.
My understanding is that this is required to perform correctly the sensor setup.

However, In the end of each of the calibration methods, we try to set the SRD back to the previous value, the one known as the protected _srd value.
For me, trying to do this always fails, as if the SRD method doesn't work when the SRD is set to 19.
Following this problem, the behavior i am observing is that if i run one of the calibration methods, i stay at an SRD of 19, regardless of the value i actually set, and the setup fails (returning a negative number; -6 for calibeGyro and calibAccel, and -2 for calibMag)

Commenting the instructions to set the SRD to 19, everything works fine and it looks like the sensor is calibrated and generates stable values.

My setup is:
I am using an Arduino Nano for the MCU to interface the sensors. And a non-latching interrupt based sampling, such that an ISR is waiting for an interrupt and then instructs the MCU to go and fetch the data.
Everything works well until i try to change the calibration.

Any help would be appreciated.
Thank you!

In a magnetometer calibration, the _hxfilt, _hyfilt, _hzfilt value is always 0.0. Since they are initialized by 0.0 and multiplied by them.

Add apps for updating calibration on no motion and temperature change. Detect magnetic interference.

When I set the Accel Range with IMU.setAccelRange(MPU9250::ACCEL_RANGE_4G); the statement is ignored and all readings I get are limited to 20 m/s/s (2G).
I have tried different ranges but always get only maximum 2G readings.

I have a question if there is a possibility to connect two examples together (FIFO_SPI.ino and WoM_I2C.ino) so it would send the content of FIFO only if there's motion detected.

Thanks for tips.

MPU9255 has 512 bytes FIFO and always old data will be replaced with new data. I could not find a solution to trigger Interrupt once FIFO is full.
If there is not way to use Interrupt, how to check FIFO size with SPI and Arduino.
Thanks

Hi and thank you for this library,

for some reason I encounter an error when calling "IMU.begin()". The status returns -18, so writing the control register 1 of the magnetometer to continuous measurement mode does not work.

Also, if I uncomment this section from the cpp file, the next error occurs at the gyro-calibration (IMU.begin() returns -20).

Do you have any idea what that could be based on?

Thank you for any help.

Dom

Hi,

I'm using Arduino 1.8.5
I'm trying to compile https://github.com/bolderflight/MPU9250/blob/master/examples/Basic_SPI/Basic_SPI.ino code. but I got a compile error,

Basic_SPI:27: error: 'SPI' was not declared in this scope
MPU9250 IMU(SPI,10);
^
/tmp/arduino_modified_sketch_937275/Basic_SPI.ino: In function 'void setup()':
Basic_SPI:36: error: 'class MPU9250' has no member named 'begin'
status = IMU.begin();
^
/tmp/arduino_modified_sketch_937275/Basic_SPI.ino: In function 'void loop()':
Basic_SPI:48: error: 'class MPU9250' has no member named 'readSensor'
IMU.readSensor();
^
Basic_SPI:50: error: 'class MPU9250' has no member named 'getAccelX_mss'
Serial.print(IMU.getAccelX_mss(),6);
^
Basic_SPI:52: error: 'class MPU9250' has no member named 'getAccelY_mss'
Serial.print(IMU.getAccelY_mss(),6);
^
Basic_SPI:54: error: 'class MPU9250' has no member named 'getAccelZ_mss'
Serial.print(IMU.getAccelZ_mss(),6);
^
Basic_SPI:56: error: 'class MPU9250' has no member named 'getGyroX_rads'
Serial.print(IMU.getGyroX_rads(),6);
^
Basic_SPI:58: error: 'class MPU9250' has no member named 'getGyroY_rads'
Serial.print(IMU.getGyroY_rads(),6);
Multiple libraries were found for "MPU9250.h"
^
Used: /home/tk/Arduino/libraries/MPU9250-master
Basic_SPI:60: error: 'class MPU9250' has no member named 'getGyroZ_rads'
Not used: /home/tk/Arduino/libraries/MPU9250-new
Serial.print(IMU.getGyroZ_rads(),6);
^
Basic_SPI:62: error: 'class MPU9250' has no member named 'getMagX_uT'
Serial.print(IMU.getMagX_uT(),6);
^
Basic_SPI:64: error: 'class MPU9250' has no member named 'getMagY_uT'
Serial.print(IMU.getMagY_uT(),6);
^
Basic_SPI:66: error: 'class MPU9250' has no member named 'getMagZ_uT'
Serial.print(IMU.getMagZ_uT(),6);
^
Basic_SPI:68: error: 'class MPU9250' has no member named 'getTemperature_C'
Serial.println(IMU.getTemperature_C(),6);
^
exit status 1
'SPI' was not declared in this scope

can you please help me.

Thank You.

Hi
I am trying to convert your master mode method and incorporate into the MPU6050 lib that I use for the FreeIMU library. Did a conversion but for the life of me I can not get it working. Was wondering if you could take a look and let me know what you think. What happens it that it does not appear to be connecting to the mPU9250. I am using Kris Winer's MPU9250 mini board. By the way would the t2 library and bus work with non-teensy boards.

Here is the code that I use to initialize the 9250:
`void MPU60X0::initialize9250MasterMode(){
#include "AK8963.h"

uint8_t buff[3];
uint8_t data[7];
int16_t _magScaleX, _magScaleY, _magScaleZ;	
bool test;

//set dev address for magnetometer
magDevAddr = 0x0C;

// SPI Configuration
if (bSPI) {
  SPI.begin();
	pinMode(devAddr, OUTPUT);
	digitalWrite(devAddr, HIGH);
	reset();
	delay(100);
	switchSPIEnabled(true);
	delay(1);
} else {
	switchSPIEnabled(false);
}

Serial.println("Passed SPI");
setStandbyDisable();
setSleepEnabled(false);

// select clock source to gyro
setClockSource(MPU60X0_CLOCK_PLL_XGYRO);
Serial.println(getClockSource());

// enable I2C master mode
setI2CMasterModeEnabled(1); 
Serial.println(getI2CMasterModeEnabled());
// set the I2C bus speed to 400 kHz
setMasterClockSpeed(13);
Serial.println(getMasterClockSpeed());
// set AK8963 to Power Down
test = writeAKRegister(AK8963_RA_CNTL1, AK8963_MODE_POWERDOWN);
Serial.println(test);

// reset the MPU9250
reset();

// wait for MPU-9250 to come back up
delay(1);

// reset the AK8963
writeAKRegister(AK8963_RA_CNTL2, AK8963_CNTL2_RESET);

// select clock source to gyro
setClockSource(MPU60X0_CLOCK_PLL_XGYRO);

// check the WHO AM I byte, expected value is 0x71 (decimal 113)
if( getDeviceID() != 113 ){
    Serial.print(getDeviceID()); Serial.print(", "); Serial.println("9250 WIA Does not Match");
}

// enable accelerometer and gyro
setStandbyDisable();

/* setup the accel and gyro ranges */
setFullScaleGyroRange(MPU60X0_GYRO_FS_2000);	// set gyro range to +/- 2000 deg/second
setFullScaleAccelRange(MPU60X0_ACCEL_FS_2);		// set accel range to +- 2g

// enable I2C master mode
setI2CMasterModeEnabled(true); 

// set the I2C bus speed to 400 kHz
setMasterClockSpeed(13);

// check AK8963 WHO AM I register, expected value is 0x48 (decimal 72)
readAKRegisters(AK8963_RA_WIA, sizeof(buff), &buff[0]);
if(  buff[0] != 72 ){
    Serial.print(buff[0]); Serial.print(", ");Serial.println("AK does not match");
}

/* get the magnetometer calibration */

// set AK8963 to Power Down
writeAKRegister(AK8963_RA_CNTL1, AK8963_MODE_POWERDOWN);

delay(100); // long wait between AK8963 mode changes

// set AK8963 to FUSE ROM access
writeAKRegister(AK8963_RA_CNTL2, AK8963_MODE_FUSEROM);

delay(100); // long wait between AK8963 mode changes

// read the AK8963 ASA registers and compute magnetometer scale factors
readAKRegisters(AK8963_RA_ASAX, sizeof(buff), &buff[0]);
//_magScaleX = ((((float)buff[0]) - 128.0f)/(256.0f) + 1.0f) * 4912.0f / 32760.0f; // micro Tesla
//_magScaleY = ((((float)buff[1]) - 128.0f)/(256.0f) + 1.0f) * 4912.0f / 32760.0f; // micro Tesla
//_magScaleZ = ((((float)buff[2]) - 128.0f)/(256.0f) + 1.0f) * 4912.0f / 32760.0f; // micro Tesla 
_magScaleX = buff[0];
_magScaleX = buff[1];
_magScaleX = buff[2];
Serial.print(_magScaleX,8); Serial.print(", "); Serial.print(_magScaleY,8); 
Serial.print(", "); Serial.println(_magScaleZ,8);

// set AK8963 to Power Down
writeAKRegister(AK8963_RA_CNTL1, AK8963_MODE_POWERDOWN);
delay(100); // long wait between AK8963 mode changes  

// set AK8963 to 16 bit resolution, 100 Hz update rate
writeRegister(AK8963_RA_CNTL1, 0x16);
delay(100); // long wait between AK8963 mode changes

// select clock source to gyro
setClockSource(MPU60X0_CLOCK_PLL_XGYRO); 

// instruct the MPU9250 to get 7 bytes of data from the AK8963 at the sample rate
readAKRegisters(AK8963_RA_HXL,sizeof(data),&data[0]);

// successful init, return 0
Serial.println("FINISHED");

}

void MPU60X0::getMotion9Counts(int16_t* ax, int16_t* ay, int16_t* az, int16_t* gx, int16_t* gy, int16_t* gz, int16_t* hx, int16_t* hy, int16_t* hz)
{
uint8_t buff[21];
int16_t axx, ayy, azz, gxx, gyy, gzz;

readRegister(MPU60X0_RA_ACCEL_XOUT_H, sizeof(buff), &buff[0]); // grab the data from the MPU9250

axx = (((int16_t)buff[0]) << 8) | buff[1];  // combine into 16 bit values
ayy = (((int16_t)buff[2]) << 8) | buff[3];
azz = (((int16_t)buff[4]) << 8) | buff[5];

gxx = (((int16_t)buff[8]) << 8) | buff[9];
gyy = (((int16_t)buff[10]) << 8) | buff[11];
gzz = (((int16_t)buff[12]) << 8) | buff[13];

*hx = (((int16_t)buff[15]) << 8) | buff[14];  
*hy = (((int16_t)buff[17]) << 8) | buff[16];
*hz = (((int16_t)buff[19]) << 8) | buff[18];

//*ax = tX[0]*axx + tX[1]*ayy + tX[2]*azz; // transform axes
//*ay = tY[0]*axx + tY[1]*ayy + tY[2]*azz;
//*az = tZ[0]*axx + tZ[1]*ayy + tZ[2]*azz;

//*gx = tX[0]*gxx + tX[1]*gyy + tX[2]*gzz;
//*gy = tY[0]*gxx + tY[1]*gyy + tY[2]*gzz;
//*gz = tZ[0]*gxx + tZ[1]*gyy + tZ[2]*gzz;

}

/* get accelerometer, gyro, and magnetometer data given pointers to store values /
void MPU60X0::getMotion9(float ax, float* ay, float* az, float* gx, float* gy, float* gz, float* hx, float* hy, float* hz){
int16_t accel[3];
int16_t gyro[3];
int16_t mag[3];

getMotion9Counts(&accel[0], &accel[1], &accel[2], &gyro[0], &gyro[1], &gyro[2], &mag[0], &mag[1], &mag[2]);

*ax = ((float) accel[0]); // typecast and scale to values
*ay = ((float) accel[1]);
*az = ((float) accel[2]);

*gx = ((float) gyro[0]);
*gy = ((float) gyro[1]);
*gz = ((float) gyro[2]);

*hx = ((float) mag[0]);
*hy = ((float) mag[1]);
*hz = ((float) mag[2]);

}

//========================================================
void MPU60X0::readRegister(uint8_t subAddress, uint8_t count, uint8_t* dest){
Wire.beginTransmission(devAddr); // open the device
Wire.write(subAddress); // specify the starting register address
Wire.endTransmission(false);

    Wire.requestFrom(devAddr, count); // specify the number of bytes to receive

}

/* writes a register to the AK8963 given a register address and data */
bool MPU60X0::writeAKRegister(uint8_t subAddress, uint8_t data){
uint8_t count = 1;
uint8_t buff[1];
writeRegister(MPU60X0_RA_I2C_SLV0_ADDR, AK8963_DEFAULT_ADDRESS); // set slave 0 to the AK8963 and set for write
writeRegister(MPU60X0_RA_I2C_SLV0_REG,subAddress); // set the register to the desired AK8963 sub address
writeRegister(MPU60X0_RA_I2C_SLV0_DO,data); // store the data for write
writeRegister(MPU60X0_RA_I2C_SLV0_CTRL,I2C_SLV0_EN | count); // enable I2C and send 1 byte

// read the register and confirm
readAKRegisters(subAddress, sizeof(buff), &buff[0]);

if(buff[0] == data) {
	return true;
}
else{
	return false;
}

}

/* reads registers from the AK8963 /
void MPU60X0::readAKRegisters(uint8_t subAddress, uint8_t count, uint8_t dest){

writeRegister(MPU60X0_RA_I2C_SLV0_ADDR, magDevAddr | I2C_READ_FLAG); // set slave 0 to the AK8963 and set for read
writeRegister(MPU60X0_RA_I2C_SLV0_REG,  subAddress); // set the register to the desired AK8963 sub address
writeRegister(MPU60X0_RA_I2C_SLV0_CTRL, I2C_SLV0_EN | count); // enable I2C and request the bytes
delay(1); // takes some time for these registers to fill
readRegister(MPU60X0_RA_EXT_SENS_DATA_00,count,dest); // read the bytes off the MPU9250 EXT_SENS_DATA registers

}

void MPU60X0::writeRegister(uint8_t subAddress, uint8_t data){

Wire.beginTransmission(devAddr); // open the device
Wire.write(subAddress); // write the register address
Wire.write(data); // write the data
Wire.endTransmission();

delay(10); // need to slow down how fast I write to MPU9250

}

void MPU60X0::writeMagRegister(uint8_t subAddress, uint8_t data){

Wire.beginTransmission(magDevAddr); // open the device
Wire.write(subAddress); // write the register address
Wire.write(data); // write the data
Wire.endTransmission();

delay(10); // need to slow down how fast I write to MPU9250

}
/** Verify the I2C/SPI connection.

• Make sure the device is connected and responds as expected.
• @return True if connection is valid, false otherwise
  */
  bool MPU60X0::testConnection() {
  return getDeviceID() == 0b110100 || getDeviceID() == 0x71;
  }
  `

This repository seems much helpful but there can be many other like me who feel afraid of wrong wiring so , in ReadMe file or here, it would be great to share a sample working wiring diagram using any one of the Arduino boards, preferably Arduino UNO, Arduino Mega, Arduino Nano, STM32F1 board, etc.

I require some help calculating the heading relative to magnetic north with this library and an MPU9250.

float heading_m = (atan2(IMU.getMagY_uT(), IMU.getMagX_uT()) * 180) / PI;
does not work as with other magnetometer examples ( Adafruit Example for Heading) 😞

As far as I understand, the readings gathered by the library do not represent vectors as it is the case with the Adafruit code. Adding a function to this library to calculate the heading would be extremely useful!

Thanks in advance!

Hello, I'm using this library on arduino 1.8.5 but master branch gives me this error:

MPU9250.h:123:5: error: 'TwoWire' does not name a type
TwoWire *_i2c;
^
exit status 1

I'm calling readSensor function in interrupts (first in setup() call enableDataReadyInterrupt()) and using I2C connection. interrupt is received and go to function but then it hangs and running code is stoped. why did this happen?

#include "MPU9250.h"

// an MPU9250 object with the MPU-9250 sensor on I2C bus 0 with address 0x68
MPU9250 IMU(Wire,0x68);
int status;

void setup() {
// serial to display data
Serial.begin(115200);
while(!Serial) {}
// start communication with IMU
status = IMU.begin();
if (status < 0) {
Serial.println("IMU initialization unsuccessful");
Serial.println("Check IMU wiring or try cycling power");
Serial.print("Status: ");
Serial.println(status);
while(1) {}
}
else Serial.println("initiate ok");
// setting the accelerometer full scale range to +/-16G
IMU.setAccelRange(MPU9250::ACCEL_RANGE_16G);
// setting the gyroscope full scale range to +/-500 deg/s
IMU.setGyroRange(MPU9250::GYRO_RANGE_500DPS);
// setting DLPF bandwidth to 20 Hz
IMU.setDlpfBandwidth(MPU9250::DLPF_BANDWIDTH_20HZ);
// setting SRD to 19 for a 50 Hz update rate
IMU.setSrd(19);
// enabling the data ready interrupt
IMU.enableDataReadyInterrupt();
// attaching the interrupt to microcontroller pin 1
pinMode(2,INPUT);
attachInterrupt(digitalPinToInterrupt(2),getIMU,RISING);
}

void loop() {
// display the data
Serial.println("loop");
/* Serial.print(IMU.getAccelX_mss(),6);
Serial.print("\t");
Serial.print(IMU.getAccelY_mss(),6);
Serial.print("\t");
Serial.print(IMU.getAccelZ_mss(),6);
Serial.print("\t");
Serial.print(IMU.getGyroX_rads(),6);
Serial.print("\t");
Serial.print(IMU.getGyroY_rads(),6);
Serial.print("\t");
Serial.print(IMU.getGyroZ_rads(),6);
Serial.print("\t");
Serial.print(IMU.getMagX_uT(),6);
Serial.print("\t");
Serial.print(IMU.getMagY_uT(),6);
Serial.print("\t");
Serial.print(IMU.getMagZ_uT(),6);
Serial.print("\t");
Serial.println(IMU.getTemperature_C(),6);*/
}

void getIMU(){
// read the sensor
IMU.readSensor();
Serial.println("interrupts");
}

Hello all,

Setting:

I am working on a system where multiple MPU9250 IMUs (6, to be specific) are connected to an ESP32 MCU via SPI. Using SPI as the communication bus is crucial because the I2C pins are occupied. If it's relevant, sensors are divided as 3 sensors to VSPI and 3 sensors to HSPI.

Problem:

The Mag values freeze for multiple sensors after being initialized without any problem. The sketch follows the initialization sequence given in the example Basic_SPI from the examples directory.

Moreover, freezing of the mag values is not deterministic between different runs (some mags freeze after a few seconds, some after a minute and so on), proving it very hard to detect what is going on. I have tried keeping every sensor steady (i.e. without any motion, so that the SPI connections remain stable), but the problem persists. Also - Accel and Gyro continue to give the data as expected, so the SPI connection between the MCU and IMUs cannot be an issue.

Can you please provide some pointers as to how should I try debugging this behavior of the sensors?

After I run the calibrateMag() method the bias and scales are returning 0.000 and 1.000

I have tried waving it in a big figure 8, a small figure 8, a slow figure 8, fast figure 8 and leaving it still.

Any idea why?

Hi!

I am trying to read a MPU9250 following the same configurations as the Advanced_I2C example (ACCEL_RANGE_8G, GYRO_RANGE_500DPS, DLPF_BANDWIDTH_20HZ, SRC=19) but I am having weird measurements. Apparently, only one of every two measurements is correct:

Accel( -0.002394, 0.603370, 0.002394)
Accel( -0.035915, 0.615341, -9.907711)
Accel( -0.002394, 2.449393, 0.002394)
Accel( -0.047886, 0.644073, -9.843065)
Accel( -0.002394, 0.687171, 0.002394)
Accel( -0.019155, 0.691960, -9.888557)
Accel( -0.038309, 0.610553, -20.837799)

The same happens with the magnetic field but not with the gyroscope and after a couple of minutes, my MPU stops responding.

Any ideas on why this could be happening?

More context: when I run the "Advanced_I2C" example as is, everything works correctly. My implementation is in code where I am reading a pressure sensor as well and sending everything (acceleration, gyroscope, magnetometer, pressure) via a LoRa transmitter.

Add uncompensated accel, gyro, and mag output.

hi brian, as i always say this is the best library for mpu9250
you should add it to the library manager
please see: https://github.com/arduino/Arduino/wiki/Library-Manager-FAQ

idem for the AHRS lib

I found that the data I get by simple importing the basic_i2c.ino and the data I got is not in a correct order.
Ax and Ay are reversed and gx and gy as well. does anyone get the same problem?
I am using this chip: https://www.makerlab-electronics.com/product/mpu9250-9-dof-3-axis-accelerometer-gyro-magnetometer/

Hey, I'm trying to use the MPU9250 in combination with an ESP32 Dev Board instead of an Arduino. I already tested the connection with an I2C Scanner and it shows that there is a device connected with address 0x68 (SDA and SCL are Pins 21 and 22 on the ESP32).
But when I start the Basic_I2C Example, I always get status = -1 from IMU.begin(). My wiring should be correct.
Do you have any idea what the problem is and how I can get this working?

The Z axis is not changing its value but I turn it at the right position and it is only changing if I turn it at the X or the Y axis then its the opposit of the x/y value. Do you know something about this problem?
(The gyroscop and the magnetometer are working correctly)

Sorry for my bad english but I hope you will understand my problem.

Hi,
I am working on a small project using MPU9250 to get rotational data of the joint. As I utilizting this library with Madgwick quaternion filter, I got a very strange result, which not only drift when stationary, but also when I'm moving the sensor. (a short video showing the result: https://youtu.be/sDa7cdnEAwQ)

I guess the code for the filter is correct since it is open source and online everywhere. (In my working repo lib: https://github.com/larryyyyy/MPU9250) I was stucking in this stage to get a good quaternion for so long like several weeks... hope to get some hins here. Thank you so much!

I've been trying to run the calibration code for the MPU9250, and the calibrateMag() method seems to work, but the calibrateAccel() method simply returns bias 0 and scale 1.
I am running the function 6 times, changing the orientation of the imu with +z, -z, +y, -y, +x, -x pointing up in that order, switching whenever the "switch" serial print appears and holding position until the next.
Any ideas?

Hardware running the code: ESP8266 WeMos D1 mini with MPU9250
Code I'm running:

/*
CalibrateMPU9250.ino
Brian R Taylor
[email protected]
Copyright (c) 2017 Bolder Flight Systems
Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
and associated documentation files (the "Software"), to deal in the Software without restriction, 
including without limitation the rights to use, copy, modify, merge, publish, distribute, 
sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or 
substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include "MPU9250.h"
#include "EEPROM.h"

// an MPU-9250 object on SPI bus 0 with chip select 10
MPU9250 Imu(Wire, 0x68);
int status;

// EEPROM buffer and variable to save accel and mag bias 
// and scale factors
uint8_t EepromBuffer[48];
float value;

void setup() {
  // serial to display instructions
  Serial.begin(57600);
  while(!Serial) {}
  // start communication with IMU 
  status = Imu.begin();
  if (status < 0) {
    Serial.println("IMU initialization unsuccessful");
    Serial.println("Check IMU wiring or try cycling power");
    Serial.print("Status: ");
    Serial.println(status);
    while(1) {}
  }
  // calibrating accelerometer
  Serial.println("Starting Accelerometer Calibration");
  Imu.calibrateAccel();
  Serial.println("Switch");
  delay(5000);
  Imu.calibrateAccel();
  Serial.println("Switch");
  delay(5000);
  Imu.calibrateAccel();
  Serial.println("Switch");
  delay(5000);
  Imu.calibrateAccel();
  Serial.println("Switch");
  delay(5000);
  Imu.calibrateAccel();
  Serial.println("Switch");
  delay(5000);
  Imu.calibrateAccel();
  Serial.println("Done");
  Serial.println("Starting Magnetometer Calibration");
  delay(5000);
  // calibrating magnetometer
  Imu.calibrateMag();
  // saving to EEPROM
  value = Imu.getAccelBiasX_mss();
  memcpy(EepromBuffer,&value,4);
  Serial.print(value);
  Serial.println(": abx");
  value = Imu.getAccelScaleFactorX();
  memcpy(EepromBuffer+4,&value,4);
  Serial.print(value);
  Serial.println(": asx");
  value = Imu.getAccelBiasY_mss();
  memcpy(EepromBuffer+8,&value,4);
  Serial.print(value);
  Serial.println(": aby");
  value = Imu.getAccelScaleFactorY();
  memcpy(EepromBuffer+12,&value,4);
  Serial.print(value);
  Serial.println(": asy");
  value = Imu.getAccelBiasZ_mss();
  memcpy(EepromBuffer+16,&value,4);
  Serial.print(value);
  Serial.println(": abz");
  value = Imu.getAccelScaleFactorZ();
  memcpy(EepromBuffer+20,&value,4);
  Serial.print(value);
  Serial.println(": asz");
  value = Imu.getMagBiasX_uT();
  memcpy(EepromBuffer+24,&value,4);
  Serial.print(value);
  Serial.println(": mbx");
  value = Imu.getMagScaleFactorX();
  memcpy(EepromBuffer+28,&value,4);
  Serial.print(value);
  Serial.println(": msx");
  value = Imu.getMagBiasY_uT();
  memcpy(EepromBuffer+32,&value,4);
  Serial.print(value);
  Serial.println(": mby");
  value = Imu.getMagScaleFactorY();
  memcpy(EepromBuffer+36,&value,4);
  Serial.print(value);
  Serial.println(": msy");
  value = Imu.getMagBiasZ_uT();
  memcpy(EepromBuffer+40,&value,4);
  Serial.print(value);
  Serial.println(": mbz");
  value = Imu.getMagScaleFactorZ();
  memcpy(EepromBuffer+44,&value,4);
  Serial.print(value);
  Serial.println(": msz");
  for (size_t i=0; i < sizeof(EepromBuffer); i++) {
    EEPROM.write(i,EepromBuffer[i]);
  }
  Serial.println("Done");
}

void loop() {}

Hey Guys,
I am having issues with my esp32 and interfacing my two IMUs (MPU9250 with different addresses). Both Imus are connected to 21,22 pins of the Esp32. My setup works at times and then it doesn't work. Here's the story -

2 months ago - Got Everything working. Then it stopped. Replaced the IMUs, eventually after many resets, it began to work. Both sets of IMUs worked fine.
AND KEPT WORKING
1 week ago - IMU's stopped work (Previous night everything worked fine!!)

I am using a basic i2c scanner sketch to test my communication. When both IMUs are connected. I am getting 'no devices found 'errors. When I connect them alone, both addresses are picked up just fine. Tried the basic I2c sketches. I get the -1 status errors.

I am not using any pullup resistors. As I believe, they come with the breakout boards (generic gy boards). I don't think I need them as my setup used to worked fine for months!!. And If I do use pull resistors, what would the circuit look like given that two IMU's are being used, will the resistors be in parallel (Electronics noob here)

PLEASE HELP as these IMUs are essential to my thesis due soon!

It would be quite useful to have them
I think you should add something to calibrate while running the sketch, a function to read the calibration data and a function to write calibration data

hello
did you thought to add a filtering?
examples:
https://github.com/kriswiner/MPU9250/blob/master/quaternionFilters.ino
or the improved sparkfun version:
https://github.com/sparkfun/SparkFun_MPU-9250_Breakout_Arduino_Library

i tried myself but i wasn't able to do it

I am wondering how to wire the MPU9250 breakout board to Arduino in SPI Mode. Right now I have
Vcc - 3.3v
Gnd - Gnd
SCL - 13
SDA - 11
ADO - 12
NCS - 10

Add AHRS and / or DMP.

Hi,

Issue:
when using the library with an ESP32 connected via SPI, accelerometer and magnetometer values are corrupt. Example: Serial.print(IMU->getAccelX_mss(),6) prints "ovf".

Reason:
When not performing a calibration, numerous values for accelerometer biases such as "_axb" etc. defined in MPU9250.h are not initialized.