Code to detect walking and convert to input for video game
Dependencies: LSM9DS1_Library_cal2 XBee mbed
Fork of FootModule by
main.cpp
- Committer:
- jgensel3
- Date:
- 2017-04-30
- Revision:
- 4:43a6ec1af346
- Parent:
- 3:2d6ff72599f1
- Child:
- 5:c4ae0656a736
File content as of revision 4:43a6ec1af346:
#include "mbed.h" #include "LSM9DS1.h" #include "Wireless.h" //#include "USBKeyboard.h" //#include "MahonyAHRS.h" #define PI 3.14159 // Earth's magnetic field varies by location. Add or subtract // a declination to get a more accurate heading. Calculate // your's here: // http://www.ngdc.noaa.gov/geomag-web/#declination #define DECLINATION -4.94 // Declination (degrees) in Atlanta,GA. DigitalOut led1(LED1); DigitalOut led2(LED2); DigitalOut led3(LED3); DigitalOut led4(LED4); Serial pc(USBTX, USBRX); DigitalIn pb1(p17); //USBKeyboard keyboard; // Calculate pitch, roll, and heading. // Pitch/roll calculations taken from this app note: // http://cache.freescale.com/files/sensors/doc/app_note/AN3461.pdf?fpsp=1 // Heading calculations taken from this app note: // http://www51.honeywell.com/aero/common/documents/myaerospacecatalog-documents/Defense_Brochures-documents/Magnetic__Literature_Application_notes-documents/AN203_Compass_Heading_Using_Magnetometers.pdf #include <math.h> //--------------------------------------------------------------------------------------------------- // Definitions #define sampleFreq 952.0f // sample frequency in Hz #define betaDef 0.1f // 2 * proportional gain //--------------------------------------------------------------------------------------------------- // Variable definitions volatile float beta = betaDef; // 2 * proportional gain (Kp) volatile float q0 = 1.0f, q1 = 0.0f, q2 = 0.0f, q3 = 0.0f; // quaternion of sensor frame relative to auxiliary frame //--------------------------------------------------------------------------------------------------- // Function declarations float invSqrt(float x); //==================================================================================================== // Functions //--------------------------------------------------------------------------------------------------- // AHRS algorithm update void MadgwickAHRSupdateIMU(float gx, float gy, float gz, float ax, float ay, float az); void MadgwickAHRSupdate(float gx, float gy, float gz, float ax, float ay, float az, float mx, float my, float mz) { float recipNorm; float s0, s1, s2, s3; float qDot1, qDot2, qDot3, qDot4; float hx, hy; float _2q0mx, _2q0my, _2q0mz, _2q1mx, _2bx, _2bz, _4bx, _4bz, _2q0, _2q1, _2q2, _2q3, _2q0q2, _2q2q3, q0q0, q0q1, q0q2, q0q3, q1q1, q1q2, q1q3, q2q2, q2q3, q3q3; // Use IMU algorithm if magnetometer measurement invalid (avoids NaN in magnetometer normalisation) if((mx == 0.0f) && (my == 0.0f) && (mz == 0.0f)) { MadgwickAHRSupdateIMU(gx, gy, gz, ax, ay, az); return; } // Rate of change of quaternion from gyroscope qDot1 = 0.5f * (-q1 * gx - q2 * gy - q3 * gz); qDot2 = 0.5f * (q0 * gx + q2 * gz - q3 * gy); qDot3 = 0.5f * (q0 * gy - q1 * gz + q3 * gx); qDot4 = 0.5f * (q0 * gz + q1 * gy - q2 * gx); // Compute feedback only if accelerometer measurement valid (avoids NaN in accelerometer normalisation) if(!((ax == 0.0f) && (ay == 0.0f) && (az == 0.0f))) { // Normalise accelerometer measurement recipNorm = invSqrt(ax * ax + ay * ay + az * az); ax *= recipNorm; ay *= recipNorm; az *= recipNorm; // Normalise magnetometer measurement recipNorm = invSqrt(mx * mx + my * my + mz * mz); mx *= recipNorm; my *= recipNorm; mz *= recipNorm; // Auxiliary variables to avoid repeated arithmetic _2q0mx = 2.0f * q0 * mx; _2q0my = 2.0f * q0 * my; _2q0mz = 2.0f * q0 * mz; _2q1mx = 2.0f * q1 * mx; _2q0 = 2.0f * q0; _2q1 = 2.0f * q1; _2q2 = 2.0f * q2; _2q3 = 2.0f * q3; _2q0q2 = 2.0f * q0 * q2; _2q2q3 = 2.0f * q2 * q3; q0q0 = q0 * q0; q0q1 = q0 * q1; q0q2 = q0 * q2; q0q3 = q0 * q3; q1q1 = q1 * q1; q1q2 = q1 * q2; q1q3 = q1 * q3; q2q2 = q2 * q2; q2q3 = q2 * q3; q3q3 = q3 * q3; // Reference direction of Earth's magnetic field hx = mx * q0q0 - _2q0my * q3 + _2q0mz * q2 + mx * q1q1 + _2q1 * my * q2 + _2q1 * mz * q3 - mx * q2q2 - mx * q3q3; hy = _2q0mx * q3 + my * q0q0 - _2q0mz * q1 + _2q1mx * q2 - my * q1q1 + my * q2q2 + _2q2 * mz * q3 - my * q3q3; _2bx = sqrt(hx * hx + hy * hy); _2bz = -_2q0mx * q2 + _2q0my * q1 + mz * q0q0 + _2q1mx * q3 - mz * q1q1 + _2q2 * my * q3 - mz * q2q2 + mz * q3q3; _4bx = 2.0f * _2bx; _4bz = 2.0f * _2bz; // Gradient decent algorithm corrective step s0 = -_2q2 * (2.0f * q1q3 - _2q0q2 - ax) + _2q1 * (2.0f * q0q1 + _2q2q3 - ay) - _2bz * q2 * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (-_2bx * q3 + _2bz * q1) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + _2bx * q2 * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz); s1 = _2q3 * (2.0f * q1q3 - _2q0q2 - ax) + _2q0 * (2.0f * q0q1 + _2q2q3 - ay) - 4.0f * q1 * (1 - 2.0f * q1q1 - 2.0f * q2q2 - az) + _2bz * q3 * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (_2bx * q2 + _2bz * q0) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + (_2bx * q3 - _4bz * q1) * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz); s2 = -_2q0 * (2.0f * q1q3 - _2q0q2 - ax) + _2q3 * (2.0f * q0q1 + _2q2q3 - ay) - 4.0f * q2 * (1 - 2.0f * q1q1 - 2.0f * q2q2 - az) + (-_4bx * q2 - _2bz * q0) * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (_2bx * q1 + _2bz * q3) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + (_2bx * q0 - _4bz * q2) * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz); s3 = _2q1 * (2.0f * q1q3 - _2q0q2 - ax) + _2q2 * (2.0f * q0q1 + _2q2q3 - ay) + (-_4bx * q3 + _2bz * q1) * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (-_2bx * q0 + _2bz * q2) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + _2bx * q1 * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz); recipNorm = invSqrt(s0 * s0 + s1 * s1 + s2 * s2 + s3 * s3); // normalise step magnitude s0 *= recipNorm; s1 *= recipNorm; s2 *= recipNorm; s3 *= recipNorm; // Apply feedback step qDot1 -= beta * s0; qDot2 -= beta * s1; qDot3 -= beta * s2; qDot4 -= beta * s3; } // Integrate rate of change of quaternion to yield quaternion q0 += qDot1 * (1.0f / sampleFreq); q1 += qDot2 * (1.0f / sampleFreq); q2 += qDot3 * (1.0f / sampleFreq); q3 += qDot4 * (1.0f / sampleFreq); // Normalise quaternion recipNorm = invSqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3); q0 *= recipNorm; q1 *= recipNorm; q2 *= recipNorm; q3 *= recipNorm; } //--------------------------------------------------------------------------------------------------- // IMU algorithm update void MadgwickAHRSupdateIMU(float gx, float gy, float gz, float ax, float ay, float az) { float recipNorm; float s0, s1, s2, s3; float qDot1, qDot2, qDot3, qDot4; float _2q0, _2q1, _2q2, _2q3, _4q0, _4q1, _4q2 ,_8q1, _8q2, q0q0, q1q1, q2q2, q3q3; // Rate of change of quaternion from gyroscope qDot1 = 0.5f * (-q1 * gx - q2 * gy - q3 * gz); qDot2 = 0.5f * (q0 * gx + q2 * gz - q3 * gy); qDot3 = 0.5f * (q0 * gy - q1 * gz + q3 * gx); qDot4 = 0.5f * (q0 * gz + q1 * gy - q2 * gx); // Compute feedback only if accelerometer measurement valid (avoids NaN in accelerometer normalisation) if(!((ax == 0.0f) && (ay == 0.0f) && (az == 0.0f))) { // Normalise accelerometer measurement recipNorm = invSqrt(ax * ax + ay * ay + az * az); ax *= recipNorm; ay *= recipNorm; az *= recipNorm; // Auxiliary variables to avoid repeated arithmetic _2q0 = 2.0f * q0; _2q1 = 2.0f * q1; _2q2 = 2.0f * q2; _2q3 = 2.0f * q3; _4q0 = 4.0f * q0; _4q1 = 4.0f * q1; _4q2 = 4.0f * q2; _8q1 = 8.0f * q1; _8q2 = 8.0f * q2; q0q0 = q0 * q0; q1q1 = q1 * q1; q2q2 = q2 * q2; q3q3 = q3 * q3; // Gradient decent algorithm corrective step s0 = _4q0 * q2q2 + _2q2 * ax + _4q0 * q1q1 - _2q1 * ay; s1 = _4q1 * q3q3 - _2q3 * ax + 4.0f * q0q0 * q1 - _2q0 * ay - _4q1 + _8q1 * q1q1 + _8q1 * q2q2 + _4q1 * az; s2 = 4.0f * q0q0 * q2 + _2q0 * ax + _4q2 * q3q3 - _2q3 * ay - _4q2 + _8q2 * q1q1 + _8q2 * q2q2 + _4q2 * az; s3 = 4.0f * q1q1 * q3 - _2q1 * ax + 4.0f * q2q2 * q3 - _2q2 * ay; recipNorm = invSqrt(s0 * s0 + s1 * s1 + s2 * s2 + s3 * s3); // normalise step magnitude s0 *= recipNorm; s1 *= recipNorm; s2 *= recipNorm; s3 *= recipNorm; // Apply feedback step qDot1 -= beta * s0; qDot2 -= beta * s1; qDot3 -= beta * s2; qDot4 -= beta * s3; } // Integrate rate of change of quaternion to yield quaternion q0 += qDot1 * (1.0f / sampleFreq); q1 += qDot2 * (1.0f / sampleFreq); q2 += qDot3 * (1.0f / sampleFreq); q3 += qDot4 * (1.0f / sampleFreq); // Normalise quaternion recipNorm = invSqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3); q0 *= recipNorm; q1 *= recipNorm; q2 *= recipNorm; q3 *= recipNorm; } //--------------------------------------------------------------------------------------------------- // Fast inverse square-root // See: http://en.wikipedia.org/wiki/Fast_inverse_square_root float invSqrt(float x) { float halfx = 0.5f * x; float y = x; long i = *(long*)&y; i = 0x5f3759df - (i>>1); y = *(float*)&i; y = y * (1.5f - (halfx * y * y)); return y; } //==================================================================================================== // END OF CODE //==================================================================================================== float correctHeading(float currHeading, float forward) { float newHeading = currHeading - forward; if(newHeading < 0) newHeading = 360 + newHeading; return newHeading; } float printAttitude(float ax, float ay, float az, float mx, float my, float mz) { float roll = atan2(ay, az); float pitch = atan2(-ax, sqrt(ay * ay + az * az)); // touchy trig stuff to use arctan to get compass heading (scale is 0..360) mx = -mx; float heading; if (my == 0.0) heading = (mx < 0.0) ? 180.0 : 0.0; else heading = atan2(mx, my)*360.0/(2.0*PI); //pc.printf("heading atan=%f \n\r",heading); heading -= DECLINATION; //correct for geo location if(heading>180.0) heading = heading - 360.0; else if(heading<-180.0) heading = 360.0 + heading; else if(heading<0.0) heading = 360.0 + heading; // Convert everything from radians to degrees: //heading *= 180.0 / PI; pitch *= 180.0 / PI; roll *= 180.0 / PI; //pc.printf("Pitch: %f, Roll: %f degress\n\r",pitch,roll); //pc.printf("Magnetic Heading: %f degress\n\r",heading); return abs(heading); } bool isWalking = false; Ticker walkingTimer; Ticker resetStart; WirelessModule wireless(p9, p10, FOOT_STEP); float ax ; float ay ; float az ; float gx ; float gy ; float gz ; float mx ; float my ; float mz ; LSM9DS1 IMU(p28, p27, 0xD6, 0x3C); void printStop() { // pc.printf("stop\n\r"); wireless.sendDirection(DIR_NONE); isWalking = false; } void resetForward() { q0 = 1.0f; q1 = 0.0f; q2 = 0.0f; q3 = 0.0f; MadgwickAHRSupdate(IMU.calcGyro(gx), IMU.calcGyro(gy), IMU.calcGyro(gz), IMU.calcAccel(ax), IMU.calcAccel(ay), IMU.calcAccel(az), IMU.calcMag(mx), IMU.calcMag(my), IMU.calcMag(mz)); } int main() { //LSM9DS1 lol(p9, p10, 0x6B, 0x1E); pb1.mode(PullUp); IMU.begin(); float forward; if (!IMU.begin()) { pc.printf("Failed to communicate with LSM9DS1.\n"); } led4 = 1; IMU.calibrate(1); led4 = 0; wait(0.5); led1 = 1; led4 = 1; IMU.calibrateMag(0); led4 = 0; led2 = 1; pc.printf("Press button to set forward direction"); while(pb1 == 1) { IMU.readMag(); IMU.readAccel(); ax = IMU.calcAccel(IMU.ax); ay = IMU.calcAccel(IMU.ay); az = IMU.calcAccel(IMU.az); gx = IMU.calcGyro(IMU.gx); gy = IMU.calcGyro(IMU.gy); gz = IMU.calcGyro(IMU.gz); mx = IMU.calcMag(IMU.mx); my = IMU.calcMag(IMU.my); mz = IMU.calcMag(IMU.mz); forward = printAttitude(IMU.calcAccel(IMU.ax), IMU.calcAccel(IMU.ay), IMU.calcAccel(IMU.az), IMU.calcMag(IMU.mx), IMU.calcMag(IMU.my), IMU.calcMag(IMU.mz));; } led3 = 1; resetStart.attach(resetForward, 0.1); while(1) { while(!IMU.tempAvailable()); IMU.readTemp(); while(!IMU.magAvailable(X_AXIS)); IMU.readMag(); while(!IMU.accelAvailable()); IMU.readAccel(); while(!IMU.gyroAvailable()); IMU.readGyro(); MadgwickAHRSupdate(IMU.calcGyro(IMU.gx), IMU.calcGyro(IMU.gy), IMU.calcGyro(IMU.gz), IMU.calcAccel(IMU.ax), IMU.calcAccel(IMU.ay), IMU.calcAccel(IMU.az), IMU.calcMag(IMU.mx), IMU.calcMag(IMU.my), IMU.calcMag(IMU.mz)); float Yaw_m=atan2(2*q1*q2-2*q0*q3,2*q0*q0+2*q1*q1-1)*180/PI; float Pitch_m=-1*asin(2*q1*q3+2*q0*q2)*180/PI; float Roll_m=atan2(2*q2*q3-2*q0*q1,2*q0*q0+2*q3*q3-1)*180/PI; if( Yaw_m < 0 ) Yaw_m += 360.0; //pc.printf("yaw: %f\n\r", Yaw_m); //pc.printf("Yaw: %f\n\r Roll: %f\n\r Pitch: %f\n\n\n\r", Yaw_m, Roll_m, Pitch_m); if(abs(IMU.calcGyro(IMU.gy)) > 100) { //Calculate heading relative to forward direction float currHeading = printAttitude(IMU.calcAccel(IMU.ax), IMU.calcAccel(IMU.ay), IMU.calcAccel(IMU.az), IMU.calcMag(IMU.mx),IMU.calcMag(IMU.my), IMU.calcMag(IMU.mz)); currHeading = correctHeading(currHeading, forward); pc.printf("heading: %f\n\r", currHeading); //pc.printf("corrected heading: %f\n\r", currHeading); //Start timeout to detect when stopped walking walkingTimer.attach(printStop, 0.3); //Detect direction and send command to main mbed if((currHeading > 225 && currHeading < 315) && !isWalking) { pc.printf("left\n\r"); wireless.sendDirection(DIR_LEFT); isWalking = true; } else if((currHeading > 45 && currHeading < 135) && !isWalking) { pc.printf("right\n\r"); wireless.sendDirection(DIR_RIGHT); isWalking = true; } else if((currHeading > 135 && currHeading < 225) && !isWalking) { pc.printf("down\n\r"); wireless.sendDirection(DIR_DOWN); isWalking = true; } else if((currHeading > 315 || currHeading < 45) && !isWalking) { pc.printf("up\n\r"); wireless.sendDirection(DIR_UP); isWalking = true; } } } }