SSLM1 / Mbed 2 deprecated 2_MPU9250_attitude

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Dependencies:   mbed STM32L152withMPU-9250

main.cpp@0:1a6e8ffa801b, 2015-04-30 (annotated)

Committer:
xosuuu
Date:
Thu Apr 30 11:22:00 2015 +0000
Revision:
0:1a6e8ffa801b
Child:
1:61bf659e4a1f
void getCompassOrientation()

Who changed what in which revision?

UserRevisionLine numberNew contents of line
xosuuu 0:1a6e8ffa801b 1 #include "mbed.h"
xosuuu 0:1a6e8ffa801b 2 #include "MPU9250.h"
xosuuu 0:1a6e8ffa801b 3
xosuuu 0:1a6e8ffa801b 4 //-----------------------------------------------
xosuuu 0:1a6e8ffa801b 5 // Hyperterminal configuration:
xosuuu 0:1a6e8ffa801b 6 // 9600 bauds, 8-bit data, 1 stop bit, no parity
xosuuu 0:1a6e8ffa801b 7 //-----------------------------------------------
xosuuu 0:1a6e8ffa801b 8
xosuuu 0:1a6e8ffa801b 9 Serial pc(USBTX, USBRX); // Default: 9600 bauds, 8-bit data, 1 stop bit, no parity
xosuuu 0:1a6e8ffa801b 10 MPU9250 mpu9250;
xosuuu 0:1a6e8ffa801b 11 Timer t;
xosuuu 0:1a6e8ffa801b 12 //DigitalOut myled(LED1);
xosuuu 0:1a6e8ffa801b 13
xosuuu 0:1a6e8ffa801b 14 float sum = 0;
xosuuu 0:1a6e8ffa801b 15 uint32_t sumCount = 0;
xosuuu 0:1a6e8ffa801b 16 char buffer[14];
xosuuu 0:1a6e8ffa801b 17 uint8_t dato_leido[2];
xosuuu 0:1a6e8ffa801b 18
xosuuu 0:1a6e8ffa801b 19 int main() {
xosuuu 0:1a6e8ffa801b 20
xosuuu 0:1a6e8ffa801b 21 //___ Set up I2C: use fast (400 kHz) I2C ___
xosuuu 0:1a6e8ffa801b 22 i2c.frequency(400000);
xosuuu 0:1a6e8ffa801b 23
xosuuu 0:1a6e8ffa801b 24 pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock);
xosuuu 0:1a6e8ffa801b 25
xosuuu 0:1a6e8ffa801b 26 t.start(); // Timer ON
xosuuu 0:1a6e8ffa801b 27
xosuuu 0:1a6e8ffa801b 28 // Read the WHO_AM_I register, this is a good test of communication
xosuuu 0:1a6e8ffa801b 29 uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);
xosuuu 0:1a6e8ffa801b 30
xosuuu 0:1a6e8ffa801b 31 pc.printf("I AM 0x%x\n\r", whoami); pc.printf("I SHOULD BE 0x71\n\r");
xosuuu 0:1a6e8ffa801b 32 if (I2Cstate != 0) // error on I2C
xosuuu 0:1a6e8ffa801b 33 pc.printf("I2C failure while reading WHO_AM_I register");
xosuuu 0:1a6e8ffa801b 34
xosuuu 0:1a6e8ffa801b 35 if (whoami == 0x71) // WHO_AM_I should always be 0x71
xosuuu 0:1a6e8ffa801b 36 {
xosuuu 0:1a6e8ffa801b 37 pc.printf("MPU9250 WHO_AM_I is 0x%x\n\r", whoami);
xosuuu 0:1a6e8ffa801b 38 pc.printf("MPU9250 is online...\n\r");
xosuuu 0:1a6e8ffa801b 39 sprintf(buffer, "0x%x", whoami);
xosuuu 0:1a6e8ffa801b 40 wait(1);
xosuuu 0:1a6e8ffa801b 41
xosuuu 0:1a6e8ffa801b 42 mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration
xosuuu 0:1a6e8ffa801b 43
xosuuu 0:1a6e8ffa801b 44 mpu9250.MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values (accelerometer and gyroscope self test)
xosuuu 0:1a6e8ffa801b 45 pc.printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]);
xosuuu 0:1a6e8ffa801b 46 pc.printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]);
xosuuu 0:1a6e8ffa801b 47 pc.printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]);
xosuuu 0:1a6e8ffa801b 48 pc.printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]);
xosuuu 0:1a6e8ffa801b 49 pc.printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]);
xosuuu 0:1a6e8ffa801b 50 pc.printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]);
xosuuu 0:1a6e8ffa801b 51
xosuuu 0:1a6e8ffa801b 52 mpu9250.calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometer, load biases in bias registers
xosuuu 0:1a6e8ffa801b 53 pc.printf("x gyro bias = %f\n\r", gyroBias[0]);
xosuuu 0:1a6e8ffa801b 54 pc.printf("y gyro bias = %f\n\r", gyroBias[1]);
xosuuu 0:1a6e8ffa801b 55 pc.printf("z gyro bias = %f\n\r", gyroBias[2]);
xosuuu 0:1a6e8ffa801b 56 pc.printf("x accel bias = %f\n\r", accelBias[0]);
xosuuu 0:1a6e8ffa801b 57 pc.printf("y accel bias = %f\n\r", accelBias[1]);
xosuuu 0:1a6e8ffa801b 58 pc.printf("z accel bias = %f\n\r", accelBias[2]);
xosuuu 0:1a6e8ffa801b 59 wait(2);
xosuuu 0:1a6e8ffa801b 60
xosuuu 0:1a6e8ffa801b 61 // Initialize device for active mode read of acclerometer, gyroscope, and temperature
xosuuu 0:1a6e8ffa801b 62 mpu9250.initMPU9250();
xosuuu 0:1a6e8ffa801b 63 pc.printf("MPU9250 initialized for active data mode....\n\r");
xosuuu 0:1a6e8ffa801b 64
xosuuu 0:1a6e8ffa801b 65 // Initialize device for active mode read of magnetometer, 16 bit resolution, 100Hz.
xosuuu 0:1a6e8ffa801b 66 mpu9250.initAK8963(magCalibration);
xosuuu 0:1a6e8ffa801b 67 pc.printf("AK8963 initialized for active data mode....\n\r");
xosuuu 0:1a6e8ffa801b 68 pc.printf("Accelerometer full-scale range = %f g\n\r", 2.0f*(float)(1<<Ascale));
xosuuu 0:1a6e8ffa801b 69 pc.printf("Gyroscope full-scale range = %f deg/s\n\r", 250.0f*(float)(1<<Gscale));
xosuuu 0:1a6e8ffa801b 70 if(Mscale == 0) pc.printf("Magnetometer resolution = 14 bits\n\r");
xosuuu 0:1a6e8ffa801b 71 if(Mscale == 1) pc.printf("Magnetometer resolution = 16 bits\n\r");
xosuuu 0:1a6e8ffa801b 72 if(Mmode == 2) pc.printf("Magnetometer ODR = 8 Hz\n\r");
xosuuu 0:1a6e8ffa801b 73 if(Mmode == 6) pc.printf("Magnetometer ODR = 100 Hz\n\r");
xosuuu 0:1a6e8ffa801b 74 wait(1);
xosuuu 0:1a6e8ffa801b 75 }
xosuuu 0:1a6e8ffa801b 76
xosuuu 0:1a6e8ffa801b 77 else // Connection failure
xosuuu 0:1a6e8ffa801b 78 {
xosuuu 0:1a6e8ffa801b 79 pc.printf("Could not connect to MPU9250: \n\r");
xosuuu 0:1a6e8ffa801b 80 pc.printf("%#x \n", whoami);
xosuuu 0:1a6e8ffa801b 81 sprintf(buffer, "WHO_AM_I 0x%x", whoami);
xosuuu 0:1a6e8ffa801b 82 while(1) ; // Loop forever if communication doesn't happen
xosuuu 0:1a6e8ffa801b 83 }
xosuuu 0:1a6e8ffa801b 84
xosuuu 0:1a6e8ffa801b 85 mpu9250.getAres(); // Get accelerometer sensitivity
xosuuu 0:1a6e8ffa801b 86 mpu9250.getGres(); // Get gyro sensitivity
xosuuu 0:1a6e8ffa801b 87 mpu9250.getMres(); // Get magnetometer sensitivity
xosuuu 0:1a6e8ffa801b 88 pc.printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/aRes);
xosuuu 0:1a6e8ffa801b 89 pc.printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/gRes);
xosuuu 0:1a6e8ffa801b 90 pc.printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mRes);
xosuuu 0:1a6e8ffa801b 91 magbias[0] = +470.; // User environmental x-axis correction in milliGauss, should be automatically calculated
xosuuu 0:1a6e8ffa801b 92 magbias[1] = +120.; // User environmental x-axis correction in milliGauss
xosuuu 0:1a6e8ffa801b 93 magbias[2] = +125.; // User environmental x-axis correction in milliGauss
xosuuu 0:1a6e8ffa801b 94
xosuuu 0:1a6e8ffa801b 95 while(1) {
xosuuu 0:1a6e8ffa801b 96
xosuuu 0:1a6e8ffa801b 97 // If intPin goes high, all data registers have new data
xosuuu 0:1a6e8ffa801b 98 if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) { // On interrupt, check if data ready interrupt
xosuuu 0:1a6e8ffa801b 99
xosuuu 0:1a6e8ffa801b 100 mpu9250.readAccelData(accelCount); // Read the x/y/z adc values
xosuuu 0:1a6e8ffa801b 101 // Now we'll calculate the accleration value into actual g's
xosuuu 0:1a6e8ffa801b 102 if (I2Cstate != 0) //error on I2C
xosuuu 0:1a6e8ffa801b 103 pc.printf("I2C error ocurred while reading accelerometer data. I2Cstate = %d \n\r", I2Cstate);
xosuuu 0:1a6e8ffa801b 104 else{ // I2C read or write ok
xosuuu 0:1a6e8ffa801b 105 I2Cstate = 1;
xosuuu 0:1a6e8ffa801b 106 ax = (float)accelCount[0]*aRes - accelBias[0]; // get actual g value, this depends on scale being set
xosuuu 0:1a6e8ffa801b 107 ay = (float)accelCount[1]*aRes - accelBias[1];
xosuuu 0:1a6e8ffa801b 108 az = (float)accelCount[2]*aRes - accelBias[2];
xosuuu 0:1a6e8ffa801b 109 }
xosuuu 0:1a6e8ffa801b 110
xosuuu 0:1a6e8ffa801b 111 mpu9250.readGyroData(gyroCount); // Read the x/y/z adc values
xosuuu 0:1a6e8ffa801b 112 // Calculate the gyro value into actual degrees per second
xosuuu 0:1a6e8ffa801b 113 if (I2Cstate != 0) //error on I2C
xosuuu 0:1a6e8ffa801b 114 pc.printf("I2C error ocurred while reading gyrometer data. I2Cstate = %d \n\r", I2Cstate);
xosuuu 0:1a6e8ffa801b 115 else{ // I2C read or write ok
xosuuu 0:1a6e8ffa801b 116 I2Cstate = 1;
xosuuu 0:1a6e8ffa801b 117 gx = (float)gyroCount[0]*gRes - gyroBias[0]; // get actual gyro value, this depends on scale being set
xosuuu 0:1a6e8ffa801b 118 gy = (float)gyroCount[1]*gRes - gyroBias[1];
xosuuu 0:1a6e8ffa801b 119 gz = (float)gyroCount[2]*gRes - gyroBias[2];
xosuuu 0:1a6e8ffa801b 120 }
xosuuu 0:1a6e8ffa801b 121
xosuuu 0:1a6e8ffa801b 122 mpu9250.readMagData(magCount); // Read the x/y/z adc values
xosuuu 0:1a6e8ffa801b 123 // Calculate the magnetometer values in milliGauss
xosuuu 0:1a6e8ffa801b 124 // Include factory calibration per data sheet and user environmental corrections
xosuuu 0:1a6e8ffa801b 125 if (I2Cstate != 0) //error on I2C
xosuuu 0:1a6e8ffa801b 126 pc.printf("I2C error ocurred while reading magnetometer data. I2Cstate = %d \n\r", I2Cstate);
xosuuu 0:1a6e8ffa801b 127 else{ // I2C read or write ok
xosuuu 0:1a6e8ffa801b 128 I2Cstate = 1;
xosuuu 0:1a6e8ffa801b 129 mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0]; // get actual magnetometer value, this depends on scale being set
xosuuu 0:1a6e8ffa801b 130 my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];
xosuuu 0:1a6e8ffa801b 131 mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2];
xosuuu 0:1a6e8ffa801b 132 }
xosuuu 0:1a6e8ffa801b 133 }
xosuuu 0:1a6e8ffa801b 134
xosuuu 0:1a6e8ffa801b 135 Now = t.read_us();
xosuuu 0:1a6e8ffa801b 136 deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
xosuuu 0:1a6e8ffa801b 137 lastUpdate = Now;
xosuuu 0:1a6e8ffa801b 138 sum += deltat;
xosuuu 0:1a6e8ffa801b 139 sumCount++;
xosuuu 0:1a6e8ffa801b 140
xosuuu 0:1a6e8ffa801b 141 // Pass gyro rate as rad/s
xosuuu 0:1a6e8ffa801b 142 // mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
xosuuu 0:1a6e8ffa801b 143 mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
xosuuu 0:1a6e8ffa801b 144
xosuuu 0:1a6e8ffa801b 145
xosuuu 0:1a6e8ffa801b 146 // Serial print and/or display at 1.5 s rate independent of data rates
xosuuu 0:1a6e8ffa801b 147 delt_t = t.read_ms() - count;
xosuuu 0:1a6e8ffa801b 148 if (delt_t > 1500) { // update LCD once per half-second independent of read rate
xosuuu 0:1a6e8ffa801b 149 pc.printf("ax = %f", 1000*ax);
xosuuu 0:1a6e8ffa801b 150 pc.printf(" ay = %f", 1000*ay);
xosuuu 0:1a6e8ffa801b 151 pc.printf(" az = %f mg\n\r", 1000*az);
xosuuu 0:1a6e8ffa801b 152 pc.printf("gx = %f", gx);
xosuuu 0:1a6e8ffa801b 153 pc.printf(" gy = %f", gy);
xosuuu 0:1a6e8ffa801b 154 pc.printf(" gz = %f deg/s\n\r", gz);
xosuuu 0:1a6e8ffa801b 155 pc.printf("mx = %f", mx);
xosuuu 0:1a6e8ffa801b 156 pc.printf(" my = %f", my);
xosuuu 0:1a6e8ffa801b 157 pc.printf(" mz = %f mG\n\r", mz);
xosuuu 0:1a6e8ffa801b 158
xosuuu 0:1a6e8ffa801b 159
xosuuu 0:1a6e8ffa801b 160 tempCount = mpu9250.readTempData(); // Read the adc values
xosuuu 0:1a6e8ffa801b 161 if (I2Cstate != 0) //error on I2C
xosuuu 0:1a6e8ffa801b 162 pc.printf("I2C error ocurred while reading sensor temp. I2Cstate = %d \n\r", I2Cstate);
xosuuu 0:1a6e8ffa801b 163 else{ // I2C read or write ok
xosuuu 0:1a6e8ffa801b 164 I2Cstate = 1;
xosuuu 0:1a6e8ffa801b 165 temperature = ((float) tempCount) / 333.87f + 21.0f; // Temperature in degrees Centigrade
xosuuu 0:1a6e8ffa801b 166 pc.printf(" temperature = %f C\n\r", temperature);
xosuuu 0:1a6e8ffa801b 167 }
xosuuu 0:1a6e8ffa801b 168 pc.printf("q0 = %f\n\r", q[0]);
xosuuu 0:1a6e8ffa801b 169 pc.printf("q1 = %f\n\r", q[1]);
xosuuu 0:1a6e8ffa801b 170 pc.printf("q2 = %f\n\r", q[2]);
xosuuu 0:1a6e8ffa801b 171 pc.printf("q3 = %f\n\r", q[3]);
xosuuu 0:1a6e8ffa801b 172
xosuuu 0:1a6e8ffa801b 173
xosuuu 0:1a6e8ffa801b 174
xosuuu 0:1a6e8ffa801b 175
xosuuu 0:1a6e8ffa801b 176 // Define output variables from updated quaternion---these are Tait-Bryan angles, commonly used in aircraft orientation.
xosuuu 0:1a6e8ffa801b 177 // In this coordinate system, the positive z-axis is down toward Earth.
xosuuu 0:1a6e8ffa801b 178 // 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.
xosuuu 0:1a6e8ffa801b 179 // Pitch is angle between sensor x-axis and Earth ground plane, toward the Earth is positive, up toward the sky is negative.
xosuuu 0:1a6e8ffa801b 180 // Roll is angle between sensor y-axis and Earth ground plane, y-axis up is positive roll.
xosuuu 0:1a6e8ffa801b 181 // These arise from the definition of the homogeneous rotation matrix constructed from quaternions.
xosuuu 0:1a6e8ffa801b 182 // Tait-Bryan angles as well as Euler angles are non-commutative; that is, the get the correct orientation the rotations must be
xosuuu 0:1a6e8ffa801b 183 // applied in the correct order which for this configuration is yaw, pitch, and then roll.
xosuuu 0:1a6e8ffa801b 184 // For more see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles which has additional links.
xosuuu 0:1a6e8ffa801b 185
xosuuu 0:1a6e8ffa801b 186 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]);
xosuuu 0:1a6e8ffa801b 187 pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2]));
xosuuu 0:1a6e8ffa801b 188 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]);
xosuuu 0:1a6e8ffa801b 189 pitch *= 180.0f / PI;
xosuuu 0:1a6e8ffa801b 190 yaw *= 180.0f / PI;
xosuuu 0:1a6e8ffa801b 191 yaw -= 13.8f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04
xosuuu 0:1a6e8ffa801b 192 roll *= 180.0f / PI;
xosuuu 0:1a6e8ffa801b 193
xosuuu 0:1a6e8ffa801b 194 /*
xosuuu 0:1a6e8ffa801b 195 pc.printf("Yaw, Pitch, Roll: %f %f %f\n\r", yaw, pitch, roll);
xosuuu 0:1a6e8ffa801b 196 pc.printf("average rate = %f\n\r", (float) sumCount/sum);
xosuuu 0:1a6e8ffa801b 197 */
xosuuu 0:1a6e8ffa801b 198
xosuuu 0:1a6e8ffa801b 199
xosuuu 0:1a6e8ffa801b 200 myled= !myled;
xosuuu 0:1a6e8ffa801b 201 count = t.read_ms();
xosuuu 0:1a6e8ffa801b 202
xosuuu 0:1a6e8ffa801b 203 if(count > 1<<21) {
xosuuu 0:1a6e8ffa801b 204 t.start(); // start the timer over again if ~30 minutes has passed
xosuuu 0:1a6e8ffa801b 205 count = 0;
xosuuu 0:1a6e8ffa801b 206 deltat= 0;
xosuuu 0:1a6e8ffa801b 207 lastUpdate = t.read_us();
xosuuu 0:1a6e8ffa801b 208 }
xosuuu 0:1a6e8ffa801b 209 sum = 0;
xosuuu 0:1a6e8ffa801b 210 sumCount = 0;
xosuuu 0:1a6e8ffa801b 211 }
xosuuu 0:1a6e8ffa801b 212 }
xosuuu 0:1a6e8ffa801b 213 }