mpu9250

Using Arduino Sensors
#1

hi everyone,
because I need an overview of various values I decided to abandon the 3-axis sensor and buying a mpu9250..
I searched the internet and there are many libraries each with different steps in the calibration and show the values from the sensors.
I would just get the acceleration values and the rotation along the z-axis, ie its orientation in the environment (using gyroscope and magnetometer).
many speak of calibration and filters kalman or meg. I recommend you know how to proceed?

Thanks so much

#2

Unless you disclose what you want to accomplish, no one can recommend a certain filter or other processing that you might need or not with the sensor.

#3

i worked over it…
but i have problems with magnetometer…i am using this library, and it works very well…
i see that he doesn’t implement the read of magnet Z…
this is his code for gyro and magn:

void getMagData(int numLeituras)
{
    //GETS FIELD INTENSITY FROM COMPASS
  int xl, xh, yl,yh;
  int i = 0;
  float mediaMagX = 0;
  float mediaMagY = 0;
  float mediaMagZ = 0;
  for(i=0;i<numLeituras;i++)
  {
    Wire.beginTransmission(0X0C);
    Wire.write(0x03);
    Wire.endTransmission();
    Wire.requestFrom(0x0C, 4);
    xl = Wire.read();
    xh = Wire.read();
    yl = Wire.read();
    yh = Wire.read();

    mediaMagX += (xh<<8|xl) - 30;
    mediaMagY += (yh<<8|yl) - 45;

    Wire.beginTransmission(0x0C);
    Wire.write(0x0A);
    Wire.write(0x01);
    Wire.endTransmission();
  }
  magX = mediaMagX/numLeituras;
  magY = mediaMagY/numLeituras;

}

void getGyroData(int numLeituras)
{
   //GETS ANGULAR SPEED VALUES
  int i = 0;
  float mediaGyroX = 0;
  float mediaGyroY = 0;
  float mediaGyroZ = 0;

  for(i=0;i<numLeituras;i++)
  {
    Wire.beginTransmission(MPU);      //transmite
    Wire.write(0x43);                 // Endereço registrador do Gyro
    Wire.endTransmission(false);     //Finaliza transmissão
    Wire.requestFrom(MPU,6,true);   //requisita 6 bytes
    mediaGyroX += Wire.read()<<8|Wire.read();  //GYRO EIXO X
    mediaGyroY += Wire.read()<<8|Wire.read();  //GYRO EIXO Y
    mediaGyroZ += Wire.read()<<8|Wire.read();  //GYRO EIXO Z
  }

  gyroX = mediaGyroX/numLeituras;
  gyroY = mediaGyroY/numLeituras;
  gyroZ = mediaGyroZ/numLeituras;
}

i 'm thinking to modify :
Wire.requestFrom(0x0C, 4); with 6 instead of 4, for asking the three values…
but i don’t undestand this 30, and 45…
mediaMagX += (xh<<8|xl) - 30;
mediaMagY += (yh<<8|yl) - 45;
mediaMagZ+= (zh<<8|zl) - ???;

#4

You can either try a more complete library,
or with this library should not be very hard to identify in the 9250 the codes needed for magnetic z value and complete the library. I don't know why it substracts 30 from x and 45 from y.

#5