IMU.h

00001 
00002 #include "MPU6050.h"
00003 #include "communication.h"
00004 
00005 float sum = 0;
00006 uint32_t sumCount = 0;
00007 
00008 Timer t;
00009 
00010 void IMUinit(MPU6050 &mpu6050)
00011 {
00012     t.start();
00013 
00014 // Read the WHO_AM_I register, this is a good test of communication
00015     uint8_t whoami = mpu6050.readByte(MPU6050_ADDRESS, WHO_AM_I_MPU6050);  // Read WHO_AM_I register for MPU-6050
00016     pc.printf("I AM 0x%x\n\r", whoami);
00017     pc.printf("I SHOULD BE 0x68\n\r");
00018 
00019     if (whoami == 0x68) { // WHO_AM_I should always be 0x68
00020         pc.printf("MPU6050 is online...");
00021         wait(1);
00022         //lcd.clear();
00023         //lcd.printString("MPU6050 OK", 0, 0);
00024 
00025 
00026         mpu6050.MPU6050SelfTest(SelfTest); // Start by performing self test and reporting values
00027         pc.printf("x-axis self test: acceleration trim within : ");
00028         pc.printf("%f", SelfTest[0]);
00029         pc.printf("% of factory value \n\r");
00030         pc.printf("y-axis self test: acceleration trim within : ");
00031         pc.printf("%f", SelfTest[1]);
00032         pc.printf("% of factory value \n\r");
00033         pc.printf("z-axis self test: acceleration trim within : ");
00034         pc.printf("%f", SelfTest[2]);
00035         pc.printf("% of factory value \n\r");
00036         pc.printf("x-axis self test: gyration trim within : ");
00037         pc.printf("%f", SelfTest[3]);
00038         pc.printf("% of factory value \n\r");
00039         pc.printf("y-axis self test: gyration trim within : ");
00040         pc.printf("%f", SelfTest[4]);
00041         pc.printf("% of factory value \n\r");
00042         pc.printf("z-axis self test: gyration trim within : ");
00043         pc.printf("%f", SelfTest[5]);
00044         pc.printf("% of factory value \n\r");
00045         wait(1);
00046 
00047         if(SelfTest[0] < 1.0f && SelfTest[1] < 1.0f && SelfTest[2] < 1.0f && SelfTest[3] < 1.0f && SelfTest[4] < 1.0f && SelfTest[5] < 1.0f) {
00048             mpu6050.resetMPU6050(); // Reset registers to default in preparation for device calibration
00049             mpu6050.calibrateMPU6050(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers
00050             mpu6050.initMPU6050();
00051             pc.printf("MPU6050 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
00052             wait(2);
00053         } else {
00054             pc.printf("Device did not the pass self-test!\n\r");
00055         }
00056     } else {
00057         pc.printf("Could not connect to MPU6050: \n\r");
00058         pc.printf("%#x \n",  whoami);
00059 
00060         while(1) ; // Loop forever if communication doesn't happen
00061     }
00062 }
00063 
00064 
00065 void IMUPrintData(MPU6050 &mpu6050)
00066 {
00067 // If data ready bit set, all data registers have new data
00068     if(mpu6050.readByte(MPU6050_ADDRESS, INT_STATUS) & 0x01) {  // check if data ready interrupt
00069         mpu6050.readAccelData(accelCount);  // Read the x/y/z adc values
00070         mpu6050.getAres();
00071 
00072         // Now we'll calculate the accleration value into actual g's
00073         ax = (float)accelCount[0]*aRes - accelBias[0];  // get actual g value, this depends on scale being set
00074         ay = (float)accelCount[1]*aRes - accelBias[1];
00075         az = (float)accelCount[2]*aRes - accelBias[2];
00076 
00077         mpu6050.readGyroData(gyroCount);  // Read the x/y/z adc values
00078         mpu6050.getGres();
00079 
00080         // Calculate the gyro value into actual degrees per second
00081         gx = (float)gyroCount[0]*gRes; // - gyroBias[0];  // get actual gyro value, this depends on scale being set
00082         gy = (float)gyroCount[1]*gRes; // - gyroBias[1];
00083         gz = (float)gyroCount[2]*gRes; // - gyroBias[2];
00084 
00085         tempCount = mpu6050.readTempData();  // Read the x/y/z adc values
00086         temperature = (tempCount) / 340. + 36.53; // Temperature in degrees Centigrade
00087     }
00088 
00089     Now = t.read_us();
00090     deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
00091     lastUpdate = Now;
00092 
00093     sum += deltat;
00094     sumCount++;
00095 
00096     if(lastUpdate - firstUpdate > 10000000.0f) {
00097         beta = 0.04;  // decrease filter gain after stabilized
00098         zeta = 0.015; // increasey bias drift gain after stabilized
00099     }
00100 
00101     // Pass gyro rate as rad/s
00102     mpu6050.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f);
00103 
00104     // Serial print and/or display at 0.5 s rate independent of data rates
00105     delt_t = t.read_ms() - count;
00106     if (delt_t > 500) { // update LCD once per half-second independent of read rate
00107 
00108         pc.printf("ax = %f", 1000*ax);
00109         pc.printf(" ay = %f", 1000*ay);
00110         pc.printf(" az = %f  mg\n\r", 1000*az);
00111 
00112         pc.printf("gx = %f", gx);
00113         pc.printf(" gy = %f", gy);
00114         pc.printf(" gz = %f  deg/s\n\r", gz);
00115 
00116         pc.printf(" temperature = %f  C\n\r", temperature);
00117 
00118         pc.printf("q0 = %f\n\r", q[0]);
00119         pc.printf("q1 = %f\n\r", q[1]);
00120         pc.printf("q2 = %f\n\r", q[2]);
00121         pc.printf("q3 = %f\n\r", q[3]);
00122 
00123         // Define output variables from updated quaternion---these are Tait-Bryan angles, commonly used in aircraft orientation.
00124         // In this coordinate system, the positive z-axis is down toward Earth.
00125         // 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.
00126         // Pitch is angle between sensor x-axis and Earth ground plane, toward the Earth is positive, up toward the sky is negative.
00127         // Roll is angle between sensor y-axis and Earth ground plane, y-axis up is positive roll.
00128         // These arise from the definition of the homogeneous rotation matrix constructed from quaternions.
00129         // Tait-Bryan angles as well as Euler angles are non-commutative; that is, the get the correct orientation the rotations must be
00130         // applied in the correct order which for this configuration is yaw, pitch, and then roll.
00131         // For more see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles which has additional links.
00132         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]);
00133         pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2]));
00134         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]);
00135         pitch *= 180.0f / PI;
00136         yaw   *= 180.0f / PI;
00137         roll  *= 180.0f / PI;
00138 
00139 //    pc.printf("Yaw, Pitch, Roll: \n\r");
00140 //    pc.printf("%f", yaw);
00141 //    pc.printf(", ");
00142 //    pc.printf("%f", pitch);
00143 //    pc.printf(", ");
00144 //    pc.printf("%f\n\r", roll);
00145 //    pc.printf("average rate = "); pc.printf("%f", (sumCount/sum)); pc.printf(" Hz\n\r");
00146 
00147         pc.printf("Yaw, Pitch, Roll: %f %f %f\n\r", yaw, pitch, roll);
00148         pc.printf("average rate = %f\n\r", (float) sumCount/sum);
00149 
00150         //myled= !myled;
00151         count = t.read_ms();
00152         sum = 0;
00153         sumCount = 0;
00154     }
00155 }
00156 
00157 void IMUUpdate(MPU6050 &mpu6050)
00158 {
00159     // If data ready bit set, all data registers have new data
00160     if(mpu6050.readByte(MPU6050_ADDRESS, INT_STATUS) & 0x01) {  // check if data ready interrupt
00161         mpu6050.readAccelData(accelCount);  // Read the x/y/z adc values
00162         mpu6050.getAres();
00163 
00164         // Now we'll calculate the accleration value into actual g's
00165         ax = (float)accelCount[0]*aRes - accelBias[0];  // get actual g value, this depends on scale being set
00166         ay = (float)accelCount[1]*aRes - accelBias[1];
00167         az = (float)accelCount[2]*aRes - accelBias[2];
00168 
00169         mpu6050.readGyroData(gyroCount);  // Read the x/y/z adc values
00170         mpu6050.getGres();
00171 
00172         // Calculate the gyro value into actual degrees per second
00173         gx = (float)gyroCount[0]*gRes; // - gyroBias[0];  // get actual gyro value, this depends on scale being set
00174         gy = (float)gyroCount[1]*gRes; // - gyroBias[1];
00175         gz = (float)gyroCount[2]*gRes; // - gyroBias[2];
00176 
00177         tempCount = mpu6050.readTempData();  // Read the x/y/z adc values
00178         temperature = (tempCount) / 340. + 36.53; // Temperature in degrees Centigrade
00179     }
00180 
00181     Now = t.read_us();
00182     deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
00183     lastUpdate = Now;
00184 
00185     sum += deltat;
00186     sumCount++;
00187 
00188     if(lastUpdate - firstUpdate > 10000000.0f) {
00189         beta = 0.04;  // decrease filter gain after stabilized
00190         zeta = 0.015; // increasey bias drift gain after stabilized
00191     }
00192 
00193     // Pass gyro rate as rad/s
00194     mpu6050.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f);
00195 
00196     // Serial print and/or display at 0.5 s rate independent of data rates
00197     delt_t = t.read_ms() - count;
00198 
00199     // Define output variables from updated quaternion---these are Tait-Bryan angles, commonly used in aircraft orientation.
00200     // In this coordinate system, the positive z-axis is down toward Earth.
00201     // 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.
00202     // Pitch is angle between sensor x-axis and Earth ground plane, toward the Earth is positive, up toward the sky is negative.
00203     // Roll is angle between sensor y-axis and Earth ground plane, y-axis up is positive roll.
00204     // These arise from the definition of the homogeneous rotation matrix constructed from quaternions.
00205     // Tait-Bryan angles as well as Euler angles are non-commutative; that is, the get the correct orientation the rotations must be
00206     // applied in the correct order which for this configuration is yaw, pitch, and then roll.
00207     // For more see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles which has additional links.
00208     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]);
00209     pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2]));
00210     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]);
00211     pitch *= 180.0f / PI;
00212     yaw   *= 180.0f / PI;
00213     roll  *= 180.0f / PI;
00214 
00215     count = t.read_ms();
00216     sum = 0;
00217     sumCount = 0;
00218 
00219 }