Janek Mann
Library version of MPU9250AHRS code.
Fork of
MPU9250AHRS
by 
Janek Mann
Diff: MPU9250.h
- Revision:
- 4:404c35f32ce3
- Parent:
- 3:c05fbe0aef1f
- Child:
- 5:ea541d293095
diff -r c05fbe0aef1f -r 404c35f32ce3 MPU9250.h
--- a/MPU9250.h Thu Sep 04 20:16:36 2014 +0000
+++ b/MPU9250.h Thu Sep 04 21:19:05 2014 +0000
@@ -190,12 +190,12 @@
float aRes, gRes, mRes; // scale resolutions per LSB for the sensors
//Set up I2C, (SDA,SCL)
-I2C i2c(I2C_SDA, I2C_SCL);
+//I2C i2c(I2C_SDA, I2C_SCL);
-DigitalOut myled(LED1);
+//DigitalOut myled(LED1);
// Pin definitions
-int intPin = 12; // These can be changed, 2 and 3 are the Arduinos ext int pins
+//int intPin = 12; // These can be changed, 2 and 3 are the Arduinos ext int pins
int16_t accelCount[3]; // Stores the 16-bit signed accelerometer sensor output
int16_t gyroCount[3]; // Stores the 16-bit signed gyro sensor output
@@ -216,13 +216,10 @@
float beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta
float GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
float zeta = sqrt(3.0f / 4.0f) * GyroMeasDrift; // compute zeta, the other free parameter in the Madgwick scheme usually set to a small or zero value
-#define Kp 2.0f * 5.0f // these are the free parameters in the Mahony filter and fusion scheme, Kp for proportional feedback, Ki for integral
-#define Ki 0.0f
float pitch, yaw, roll;
float deltat = 0.0f; // integration interval for both filter schemes
int lastUpdate = 0, firstUpdate = 0, Now = 0; // used to calculate integration interval // used to calculate integration interval
-float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion
float eInt[3] = {0.0f, 0.0f, 0.0f}; // vector to hold integral error for Mahony method
class MPU9250
@@ -235,8 +232,8 @@
//===================================================================================================================
//====== Set of useful function to access acceleratio, gyroscope, and temperature data
//===================================================================================================================
- MPU9250(I2C *i2c) _i2c( i2c ) {
- break;
+ MPU9250(I2C *i2c) : _i2c( i2c ) {
+
}
void writeByte(uint8_t address, uint8_t subAddress, uint8_t data) {
@@ -619,7 +616,7 @@
// Configure the accelerometer for self-test
writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g
writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
- delay(25); // Delay a while to let the device stabilize
+ wait(25); // Delay a while to let the device stabilize
for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer
@@ -642,7 +639,7 @@
// Configure the gyro and accelerometer for normal operation
writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00);
writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);
- delay(25); // Delay a while to let the device stabilize
+ wait(25); // Delay a while to let the device stabilize
// Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg
selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results
@@ -670,195 +667,5 @@
}
-
-// Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
-// (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
-// which fuses acceleration, rotation rate, and magnetic moments to produce a quaternion-based estimate of absolute
-// device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
-// The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms
-// but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz!
-
- void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz) {
- float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
- float norm;
- float hx, hy, _2bx, _2bz;
- float s1, s2, s3, s4;
- float qDot1, qDot2, qDot3, qDot4;
-
- // Auxiliary variables to avoid repeated arithmetic
- float _2q1mx;
- float _2q1my;
- float _2q1mz;
- float _2q2mx;
- float _4bx;
- float _4bz;
- float _2q1 = 2.0f * q1;
- float _2q2 = 2.0f * q2;
- float _2q3 = 2.0f * q3;
- float _2q4 = 2.0f * q4;
- float _2q1q3 = 2.0f * q1 * q3;
- float _2q3q4 = 2.0f * q3 * q4;
- float q1q1 = q1 * q1;
- float q1q2 = q1 * q2;
- float q1q3 = q1 * q3;
- float q1q4 = q1 * q4;
- float q2q2 = q2 * q2;
- float q2q3 = q2 * q3;
- float q2q4 = q2 * q4;
- float q3q3 = q3 * q3;
- float q3q4 = q3 * q4;
- float q4q4 = q4 * q4;
-
- // Normalise accelerometer measurement
- norm = sqrt(ax * ax + ay * ay + az * az);
- if (norm == 0.0f) return; // handle NaN
- norm = 1.0f/norm;
- ax *= norm;
- ay *= norm;
- az *= norm;
-
- // Normalise magnetometer measurement
- norm = sqrt(mx * mx + my * my + mz * mz);
- if (norm == 0.0f) return; // handle NaN
- norm = 1.0f/norm;
- mx *= norm;
- my *= norm;
- mz *= norm;
-
- // Reference direction of Earth's magnetic field
- _2q1mx = 2.0f * q1 * mx;
- _2q1my = 2.0f * q1 * my;
- _2q1mz = 2.0f * q1 * mz;
- _2q2mx = 2.0f * q2 * mx;
- hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4;
- hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4;
- _2bx = sqrt(hx * hx + hy * hy);
- _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4;
- _4bx = 2.0f * _2bx;
- _4bz = 2.0f * _2bz;
-
- // Gradient decent algorithm corrective step
- s1 = -_2q3 * (2.0f * q2q4 - _2q1q3 - ax) + _2q2 * (2.0f * q1q2 + _2q3q4 - ay) - _2bz * q3 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q4 + _2bz * q2) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q3 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
- s2 = _2q4 * (2.0f * q2q4 - _2q1q3 - ax) + _2q1 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q2 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + _2bz * q4 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q3 + _2bz * q1) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q4 - _4bz * q2) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
- s3 = -_2q1 * (2.0f * q2q4 - _2q1q3 - ax) + _2q4 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q3 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + (-_4bx * q3 - _2bz * q1) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q2 + _2bz * q4) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q1 - _4bz * q3) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
- s4 = _2q2 * (2.0f * q2q4 - _2q1q3 - ax) + _2q3 * (2.0f * q1q2 + _2q3q4 - ay) + (-_4bx * q4 + _2bz * q2) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q1 + _2bz * q3) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q2 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
- norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude
- norm = 1.0f/norm;
- s1 *= norm;
- s2 *= norm;
- s3 *= norm;
- s4 *= norm;
-
- // Compute rate of change of quaternion
- qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1;
- qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2;
- qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3;
- qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4;
-
- // Integrate to yield quaternion
- q1 += qDot1 * deltat;
- q2 += qDot2 * deltat;
- q3 += qDot3 * deltat;
- q4 += qDot4 * deltat;
- norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion
- norm = 1.0f/norm;
- q[0] = q1 * norm;
- q[1] = q2 * norm;
- q[2] = q3 * norm;
- q[3] = q4 * norm;
-
-}
-
-
-
-// Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and
-// measured ones.
- void MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz) {
- float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
- float norm;
- float hx, hy, bx, bz;
- float vx, vy, vz, wx, wy, wz;
- float ex, ey, ez;
- float pa, pb, pc;
-
- // Auxiliary variables to avoid repeated arithmetic
- float q1q1 = q1 * q1;
- float q1q2 = q1 * q2;
- float q1q3 = q1 * q3;
- float q1q4 = q1 * q4;
- float q2q2 = q2 * q2;
- float q2q3 = q2 * q3;
- float q2q4 = q2 * q4;
- float q3q3 = q3 * q3;
- float q3q4 = q3 * q4;
- float q4q4 = q4 * q4;
-
- // Normalise accelerometer measurement
- norm = sqrt(ax * ax + ay * ay + az * az);
- if (norm == 0.0f) return; // handle NaN
- norm = 1.0f / norm; // use reciprocal for division
- ax *= norm;
- ay *= norm;
- az *= norm;
-
- // Normalise magnetometer measurement
- norm = sqrt(mx * mx + my * my + mz * mz);
- if (norm == 0.0f) return; // handle NaN
- norm = 1.0f / norm; // use reciprocal for division
- mx *= norm;
- my *= norm;
- mz *= norm;
-
- // Reference direction of Earth's magnetic field
- hx = 2.0f * mx * (0.5f - q3q3 - q4q4) + 2.0f * my * (q2q3 - q1q4) + 2.0f * mz * (q2q4 + q1q3);
- hy = 2.0f * mx * (q2q3 + q1q4) + 2.0f * my * (0.5f - q2q2 - q4q4) + 2.0f * mz * (q3q4 - q1q2);
- bx = sqrt((hx * hx) + (hy * hy));
- bz = 2.0f * mx * (q2q4 - q1q3) + 2.0f * my * (q3q4 + q1q2) + 2.0f * mz * (0.5f - q2q2 - q3q3);
-
- // Estimated direction of gravity and magnetic field
- vx = 2.0f * (q2q4 - q1q3);
- vy = 2.0f * (q1q2 + q3q4);
- vz = q1q1 - q2q2 - q3q3 + q4q4;
- wx = 2.0f * bx * (0.5f - q3q3 - q4q4) + 2.0f * bz * (q2q4 - q1q3);
- wy = 2.0f * bx * (q2q3 - q1q4) + 2.0f * bz * (q1q2 + q3q4);
- wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3);
-
- // Error is cross product between estimated direction and measured direction of gravity
- ex = (ay * vz - az * vy) + (my * wz - mz * wy);
- ey = (az * vx - ax * vz) + (mz * wx - mx * wz);
- ez = (ax * vy - ay * vx) + (mx * wy - my * wx);
- if (Ki > 0.0f) {
- eInt[0] += ex; // accumulate integral error
- eInt[1] += ey;
- eInt[2] += ez;
- } else {
- eInt[0] = 0.0f; // prevent integral wind up
- eInt[1] = 0.0f;
- eInt[2] = 0.0f;
- }
-
- // Apply feedback terms
- gx = gx + Kp * ex + Ki * eInt[0];
- gy = gy + Kp * ey + Ki * eInt[1];
- gz = gz + Kp * ez + Ki * eInt[2];
-
- // Integrate rate of change of quaternion
- pa = q2;
- pb = q3;
- pc = q4;
- q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * deltat);
- q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * deltat);
- q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * deltat);
- q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * deltat);
-
- // Normalise quaternion
- norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);
- norm = 1.0f / norm;
- q[0] = q1 * norm;
- q[1] = q2 * norm;
- q[2] = q3 * norm;
- q[3] = q4 * norm;
-
- }
};
#endif
\ No newline at end of file