main.cpp

00001 #include "mbed.h"
00002 #include "mbed_events.h"
00003 #include "MPU9250.h"
00004 
00005 DigitalOut led1(LED1);
00006 InterruptIn sw(USER_BUTTON);
00007 
00008 Thread eventthread;
00009 Thread imuthread;
00010 bool read_imu_isrunning;
00011 
00012 
00013 // Pin defines
00014 DigitalOut led_green(D4);
00015 
00016 //-----------------------------------------------------
00017 //IMU
00018 float sum = 0;
00019 uint32_t sumCount = 0;
00020 char buffer[14];
00021 
00022 MPU9250 mpu9250;
00023 Timer t;
00024 Serial pc(USBTX, USBRX); // tx, rx
00025 //-----------------------------------------------------
00026 
00027 void rise_handler(void)
00028 {
00029     printf("rise_handler in context %p\r\n", Thread::gettid());
00030     // Toggle LED
00031     led1 = !led1;
00032     for (int i = 0; i<10; i++) {
00033         led_green = !led_green;
00034         wait(0.5);
00035     }
00036 }
00037 
00038 void fall_handler(void)
00039 {
00040     printf("fall_handler in context %p\r\n", Thread::gettid());
00041     // Toggle LED
00042     led1 = !led1;
00043 }
00044 
00045 void readIMU()
00046 {
00047     while(read_imu_isrunning) {
00048         pc.printf("in thread readIMU\n\r");
00049         // If intPin goes high, all data registers have new data
00050         if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) {  // On interrupt, check if data ready interrupt
00051 
00052             mpu9250.readAccelData(accelCount);  // Read the x/y/z adc values
00053             // Now we'll calculate the accleration value into actual g's
00054             ax = (float)accelCount[0]*aRes - accelBias[0];  // get actual g value, this depends on scale being set
00055             ay = (float)accelCount[1]*aRes - accelBias[1];
00056             az = (float)accelCount[2]*aRes - accelBias[2];
00057 
00058             mpu9250.readGyroData(gyroCount);  // Read the x/y/z adc values
00059             // Calculate the gyro value into actual degrees per second
00060             gx = (float)gyroCount[0]*gRes - gyroBias[0];  // get actual gyro value, this depends on scale being set
00061             gy = (float)gyroCount[1]*gRes - gyroBias[1];
00062             gz = (float)gyroCount[2]*gRes - gyroBias[2];
00063 
00064             mpu9250.readMagData(magCount);  // Read the x/y/z adc values
00065             // Calculate the magnetometer values in milliGauss
00066             // Include factory calibration per data sheet and user environmental corrections
00067             mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0];  // get actual magnetometer value, this depends on scale being set
00068             my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];
00069             mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2];
00070         }
00071 
00072         Now = t.read_us();
00073         deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
00074         lastUpdate = Now;
00075 
00076         sum += deltat;
00077         sumCount++;
00078 
00079 //    if(lastUpdate - firstUpdate > 10000000.0f) {
00080 //     beta = 0.04;  // decrease filter gain after stabilized
00081 //     zeta = 0.015; // increasey bias drift gain after stabilized
00082 //   }
00083 
00084         // Pass gyro rate as rad/s
00085         mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f,  my,  mx, mz);
00086         //mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
00087 
00088         // Serial print and/or display at 0.5 s rate independent of data rates
00089         delt_t = t.read_ms() - _count;
00090         if (delt_t > 50) { // update LCD once per half-second independent of read rate
00091 
00092             /*pc.printf("ax = %f", 1000*ax);
00093             pc.printf(" ay = %f", 1000*ay);
00094             pc.printf(" az = %f  mg\n\r", 1000*az);
00095 
00096             pc.printf("gx = %f", gx);
00097             pc.printf(" gy = %f", gy);
00098             pc.printf(" gz = %f  deg/s\n\r", gz);
00099 
00100             pc.printf("gx = %f", mx);
00101             pc.printf(" gy = %f", my);
00102             pc.printf(" gz = %f  mG\n\r", mz);*/
00103 
00104             tempCount = mpu9250.readTempData();  // Read the adc values
00105             temperature = ((float) tempCount) / 333.87f + 21.0f; // Temperature in degrees Centigrade
00106             //pc.printf(" temperature = %f  C\n\r", temperature);
00107 
00108             /*pc.printf("q0 = %f\n\r", q[0]);
00109             pc.printf("q1 = %f\n\r", q[1]);
00110             pc.printf("q2 = %f\n\r", q[2]);
00111             pc.printf("q3 = %f\n\r", q[3]);*/
00112 
00113             /*    lcd.clear();
00114                 lcd.printString("MPU9250", 0, 0);
00115                 lcd.printString("x   y   z", 0, 1);
00116                 sprintf(buffer, "%d %d %d mg", (int)(1000.0f*ax), (int)(1000.0f*ay), (int)(1000.0f*az));
00117                 lcd.printString(buffer, 0, 2);
00118                 sprintf(buffer, "%d %d %d deg/s", (int)gx, (int)gy, (int)gz);
00119                 lcd.printString(buffer, 0, 3);
00120                 sprintf(buffer, "%d %d %d mG", (int)mx, (int)my, (int)mz);
00121                 lcd.printString(buffer, 0, 4);
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             yaw   -= 2.93f; // Declination at 8572 Berg TG: +2° 56'
00138             roll  *= 180.0f / PI;
00139 
00140             pc.printf("Yaw, Pitch, Roll: %f %f %f\n\r", yaw, pitch, roll);
00141             //pc.printf("average rate = %f\n\r", (float) sumCount/sum);
00142 //    sprintf(buffer, "YPR: %f %f %f", yaw, pitch, roll);
00143 //    lcd.printString(buffer, 0, 4);
00144 //    sprintf(buffer, "rate = %f", (float) sumCount/sum);
00145 //    lcd.printString(buffer, 0, 5);
00146 
00147             myled= !myled;
00148             _count = t.read_ms();
00149 
00150             if(_count > 1<<21) {
00151                 t.start(); // start the timer over again if ~30 minutes has passed
00152                 _count = 0;
00153                 deltat= 0;
00154                 lastUpdate = t.read_us();
00155             }
00156             sum = 0;
00157             sumCount = 0;
00158         }
00159     }
00160 }
00161 
00162 void imuSetup()
00163 {
00164     read_imu_isrunning = true;
00165     //Set up I2C
00166     i2c.frequency(400000);  // use fast (400 kHz) I2C
00167 
00168     pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock);
00169 
00170     t.start();
00171 //  lcd.setBrightness(0.05);
00172 
00173 
00174     // Read the WHO_AM_I register, this is a good test of communication
00175     uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);  // Read WHO_AM_I register for MPU-9250
00176     pc.printf("I AM 0x%x\n\r", whoami);
00177     pc.printf("I SHOULD BE 0x71\n\r");
00178 
00179     if (whoami == 0x71) { // WHO_AM_I should always be 0x68
00180         pc.printf("MPU9250 WHO_AM_I is 0x%x\n\r", whoami);
00181         pc.printf("MPU9250 is online...\n\r");
00182         sprintf(buffer, "0x%x", whoami);
00183         wait(1);
00184 
00185         mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration
00186         mpu9250.MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values
00187         pc.printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]);
00188         pc.printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]);
00189         pc.printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]);
00190         pc.printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]);
00191         pc.printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]);
00192         pc.printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]);
00193         mpu9250.calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers
00194         pc.printf("x gyro bias = %f\n\r", gyroBias[0]);
00195         pc.printf("y gyro bias = %f\n\r", gyroBias[1]);
00196         pc.printf("z gyro bias = %f\n\r", gyroBias[2]);
00197         pc.printf("x accel bias = %f\n\r", accelBias[0]);
00198         pc.printf("y accel bias = %f\n\r", accelBias[1]);
00199         pc.printf("z accel bias = %f\n\r", accelBias[2]);
00200         wait(2);
00201         mpu9250.initMPU9250();
00202         pc.printf("MPU9250 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
00203         mpu9250.initAK8963(magCalibration);
00204         pc.printf("AK8963 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer
00205         pc.printf("Accelerometer full-scale range = %f  g\n\r", 2.0f*(float)(1<<Ascale));
00206         pc.printf("Gyroscope full-scale range = %f  deg/s\n\r", 250.0f*(float)(1<<Gscale));
00207         if(Mscale == 0) pc.printf("Magnetometer resolution = 14  bits\n\r");
00208         if(Mscale == 1) pc.printf("Magnetometer resolution = 16  bits\n\r");
00209         if(Mmode == 2) pc.printf("Magnetometer ODR = 8 Hz\n\r");
00210         if(Mmode == 6) pc.printf("Magnetometer ODR = 100 Hz\n\r");
00211         wait(1);
00212     } else {
00213         pc.printf("Could not connect to MPU9250: \n\r");
00214         pc.printf("%#x \n",  whoami);
00215         sprintf(buffer, "WHO_AM_I 0x%x", whoami);
00216 
00217         while(1) {
00218             // Loop forever if communication doesn't happen
00219             pc.printf("commication not happening\n\r");
00220         }
00221     }
00222 
00223     mpu9250.getAres(); // Get accelerometer sensitivity
00224     mpu9250.getGres(); // Get gyro sensitivity
00225     mpu9250.getMres(); // Get magnetometer sensitivity
00226     pc.printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/aRes);
00227     pc.printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/gRes);
00228     pc.printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mRes);
00229     magbias[0] = +470.;  // User environmental x-axis correction in milliGauss, should be automatically calculated
00230     magbias[1] = +120.;  // User environmental x-axis correction in milliGauss
00231     magbias[2] = +125.;  // User environmental x-axis correction in milliGauss
00232 }
00233 
00234 
00235 int main()
00236 {
00237     pc.baud(9600);
00238     imuSetup();
00239     imuthread.start(readIMU);
00240 
00241     // Request the shared queue
00242     EventQueue *queue = mbed_event_queue();
00243     printf("Starting in context %p\r\n", Thread::gettid());
00244 
00245     // The 'rise' handler will execute in IRQ context
00246     sw.rise(queue->event(rise_handler));
00247     // The 'fall' handler will execute in the context of the shared queue (actually the main thread)
00248     sw.fall(queue->event(fall_handler));
00249     // Setup complete, so we now dispatch the shared queue from main
00250     queue->dispatch_forever();
00251 }