![](/media/cache/group/11700697_10200701668420946_8214886085951071495_o.jpg.50x50_q85.jpg)
Class of MPU9250
Dependencies: AHRS_fillter mbed
Fork of MPU9250AHRS by
Diff: AHRS.cpp
- Revision:
- 6:5665d427bceb
- Child:
- 7:3e74239e3778
diff -r d31487b34216 -r 5665d427bceb AHRS.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/AHRS.cpp Wed Jan 20 02:34:07 2016 +0000 @@ -0,0 +1,574 @@ +#include "AHRS.h" + +#define Kp 5.1f * 5.0f // these are the free parameters in the Mahony filter and fusion scheme, Kp for proportional feedback, Ki for integral +#define Ki 1.0f + +/*AHRS::AHRS(PinName sda, PinName scl, PinName tx, PinName rx, int address):MPU9250(sda,scl,tx,rx,address) +{ + for(int i=0; i<=3; i++) { + eInt[i] = 0; + q[i] = 0; // vector to hold quaternion + } + + q[0] = 1.0f; + + PI = 3.14159265358979323846f; + GyroMeasError = PI * (60.0f / 180.0f); // gyroscope measurement error in rads/s (start at 60 deg/s), then reduce after ~10 s to 3 + beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta + GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s) + 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 +}*/ + +/*void AHRS::MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz, float deltat) +{ + 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; + + yaw = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]); + pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2])); + roll = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]); + + float Xh = mx*cos(pitch)+my*sin(roll)*sin(pitch)-mz*cos(roll)*sin(pitch); + float Yh = my*cos(roll)+mz*sin(roll); + + float yawmag = atan2(Yh,Xh)+PI; + //////test.printf("Xh= %f Yh= %f ",Xh,Yh); + //////test.printf("Yaw[mag]= %f\n\r",yawmag*180.0f/PI); + //test.printf(",%f",yawmag*180.0f/PI); + + + + pitch *= 180.0f / PI; + yaw *= 180.0f / PI; + yaw += 180.0f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04 + roll *= 180.0f / PI; + +} + + + +// Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and +// measured ones. +void AHRS::MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz, float deltat) +{ + q1 = q[0]; + q2 = q[1]; + q3 = q[2]; + q4 = q[3]; // short name local variable for readability + + // Auxiliary variables to avoid repeated arithmetic + q1q1 = q1 * q1; + q1q2 = q1 * q2; + q1q3 = q1 * q3; + q1q4 = q1 * q4; + q2q2 = q2 * q2; + q2q3 = q2 * q3; + q2q4 = q2 * q4; + q3q3 = q3 * q3; + q3q4 = q3 * q4; + 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; + + yaw = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]); + pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2])); + roll = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]); + + Xh = mx*cos(pitch)+my*sin(roll)*sin(pitch)-mz*cos(roll)*sin(pitch); + Yh = my*cos(roll)+mz*sin(roll); + + yawmag = atan2(Yh,Xh)+PI; + ////////////test.printf("Xh= %f Yh= %f ",Xh,Yh); + //////test.printf("Yaw[mag]= %f\n\r",yawmag*180.0f/PI); + //test.printf(",%f",yawmag*180.0f/PI); + + + + pitch *= 180.0f / PI; + yaw *= 180.0f / PI; + yaw += 180.0f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04 + roll *= 180.0f / PI; +}*/ + +void AHRS::MadgwickQuaternionUpdate() +{ + 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; + + yaw = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]); + pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2])); + roll = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]); + + float Xh = mx*cos(pitch)+my*sin(roll)*sin(pitch)-mz*cos(roll)*sin(pitch); + float Yh = my*cos(roll)+mz*sin(roll); + + float yawmag = atan2(Yh,Xh)+PI; + //////test.printf("Xh= %f Yh= %f ",Xh,Yh); + //////test.printf("Yaw[mag]= %f\n\r",yawmag*180.0f/PI); + //test.printf(",%f",yawmag*180.0f/PI); + + + + pitch *= 180.0f / PI; + yaw *= 180.0f / PI; + yaw += 180.0f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04 + roll *= 180.0f / PI; + +} + + + +// Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and +// measured ones. +void AHRS::MahonyQuaternionUpdate() +{ + q1 = q[0]; + q2 = q[1]; + q3 = q[2]; + q4 = q[3]; // short name local variable for readability + + // Auxiliary variables to avoid repeated arithmetic + q1q1 = q1 * q1; + q1q2 = q1 * q2; + q1q3 = q1 * q3; + q1q4 = q1 * q4; + q2q2 = q2 * q2; + q2q3 = q2 * q3; + q2q4 = q2 * q4; + q3q3 = q3 * q3; + q3q4 = q3 * q4; + 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; + + yaw = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]); + pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2])); + roll = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]); + + Xh = mx*cos(pitch)+my*sin(roll)*sin(pitch)-mz*cos(roll)*sin(pitch); + Yh = my*cos(roll)+mz*sin(roll); + + yawmag = atan2(Yh,Xh)+PI; + ////////////test.printf("Xh= %f Yh= %f ",Xh,Yh); + //////test.printf("Yaw[mag]= %f\n\r",yawmag*180.0f/PI); + //test.printf(",%f",yawmag*180.0f/PI); + + + + pitch *= 180.0f / PI; + yaw *= 180.0f / PI; + yaw += 180.0f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04 + roll *= 180.0f / PI; +} + +void AHRS::TimeStart() +{ + t.start(); +} + +void AHRS::TimeCal() +{ + Now = t.read_us(); + deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update + lastUpdate = Now; + + sum += deltat; + sumCount++; +} + +void AHRS::Run() +{ + ReadRawAccGyroMag(); + TimeCal(); + MadgwickQuaternionUpdate(); + + delt_t = t.read_ms() - count; + if (delt_t > 500) { // update LCD once per half-second independent of read rate + + /*pc.printf("ax = %f", 1000*ax); + pc.printf(" ay = %f", 1000*ay); + pc.printf(" az = %f mg\n\r", 1000*az); + + pc.printf("gx = %f", gx); + pc.printf(" gy = %f", gy); + pc.printf(" gz = %f deg/s\n\r", gz); + + pc.printf("mx = %f", mx); + pc.printf(" my = %f", my); + pc.printf(" mz = %f mG\n\r", mz);*/ + + + //pc.printf("%f,%f,%f",mx,my,mz); + + whoami = readByte(AK8963_ADDRESS, AK8963_ST2); // Read WHO_AM_I register for MPU-9250 + // pc.printf("I AM 0x%x\n\r", whoami); pc.printf("I SHOULD BE 0x10\n\r"); + if(whoami == 0x14) { + printf("I AM 0x%x\n\r", whoami); + while(1); + } + + + readTempData(); + temperature = ((float) temperature) / 333.87f + 21.0f; // Temperature in degrees Centigrade + //pc.printf(" temperature = %f C\n\r", temperature); + + // pc.printf("q0 = %f\n\r", q[0]); + // pc.printf("q1 = %f\n\r", q[1]); + // pc.printf("q2 = %f\n\r", q[2]); + // pc.printf("q3 = %f\n\r", q[3]); + + // Define output variables from updated quaternion---these are Tait-Bryan angles, commonly used in aircraft orientation. + // In this coordinate system, the positive z-axis is down toward Earth. + // Yaw is the angle between Sensor x-axis and Earth magnetic North (or true North if corrected for local declination, looking down on the sensor positive yaw is counterclockwise. + // Pitch is angle between sensor x-axis and Earth ground plane, toward the Earth is positive, up toward the sky is negative. + // Roll is angle between sensor y-axis and Earth ground plane, y-axis up is positive roll. + // These arise from the definition of the homogeneous rotation matrix constructed from quaternions. + // Tait-Bryan angles as well as Euler angles are non-commutative; that is, the get the correct orientation the rotations must be + // applied in the correct order which for this configuration is yaw, pitch, and then roll. + // For more see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles which has additional links. + yaw = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]); + pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2])); + roll = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]); + + Xh = mx*cos(pitch)+my*sin(roll)*sin(pitch)-mz*cos(roll)*sin(pitch); + Yh = my*cos(roll)+mz*sin(roll); + + yawmag = atan2(Yh,Xh)+PI; + //pc.printf("Xh= %f Yh= %f ",Xh,Yh); + printf("Yaw[mag]= %f\n\r",yawmag*180.0f/PI); + printf(",%f",yawmag*180.0f/PI); + + + + pitch *= 180.0f / PI; + yaw *= 180.0f / PI; + yaw += 180.0f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04 + roll *= 180.0f / PI; + + //pc.printf(",%f,%f,%f\n",roll,pitch,yaw); + printf("Yaw, Pitch, Roll: %f %f %f\n\r", yaw, pitch, roll); + //pc.printf("average rate = %f\n\r", (float) sumCount/sum); +// sprintf(buffer, "YPR: %f %f %f", yaw, pitch, roll); +// lcd.printString(buffer, 0, 4); +// sprintf(buffer, "rate = %f", (float) sumCount/sum); +// lcd.printString(buffer, 0, 5); + + + + + myled= !myled; + count = t.read_ms(); + + if(count > 1<<21) { + t.start(); // start the timer over again if ~30 minutes has passed + count = 0; + deltat= 0; + lastUpdate = t.read_us(); + } + sum = 0; + sumCount = 0; + } +} + +void AHRS::printRollPitchYaw() +{ + //test.printf("roll : %f, pitch : %f, yaw : %f\n",roll,pitch,yaw); +} \ No newline at end of file