Diff: main.cpp

Revision:

0:6bf0743ece18

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Mar 28 15:28:19 2020 +0000
@@ -0,0 +1,251 @@
+#include "mbed.h"
+#include "mbed_events.h"
+#include "MPU9250.h"
+
+DigitalOut led1(LED1);
+InterruptIn sw(USER_BUTTON);
+
+Thread eventthread;
+Thread imuthread;
+bool read_imu_isrunning;
+
+
+// Pin defines
+DigitalOut led_green(D4);
+
+//-----------------------------------------------------
+//IMU
+float sum = 0;
+uint32_t sumCount = 0;
+char buffer[14];
+
+MPU9250 mpu9250;
+Timer t;
+Serial pc(USBTX, USBRX); // tx, rx
+//-----------------------------------------------------
+
+void rise_handler(void)
+{
+    printf("rise_handler in context %p\r\n", Thread::gettid());
+    // Toggle LED
+    led1 = !led1;
+    for (int i = 0; i<10; i++) {
+        led_green = !led_green;
+        wait(0.5);
+    }
+}
+
+void fall_handler(void)
+{
+    printf("fall_handler in context %p\r\n", Thread::gettid());
+    // Toggle LED
+    led1 = !led1;
+}
+
+void readIMU()
+{
+    while(read_imu_isrunning) {
+        pc.printf("in thread readIMU\n\r");
+        // If intPin goes high, all data registers have new data
+        if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) {  // On interrupt, check if data ready interrupt
+
+            mpu9250.readAccelData(accelCount);  // Read the x/y/z adc values
+            // Now we'll calculate the accleration value into actual g's
+            ax = (float)accelCount[0]*aRes - accelBias[0];  // get actual g value, this depends on scale being set
+            ay = (float)accelCount[1]*aRes - accelBias[1];
+            az = (float)accelCount[2]*aRes - accelBias[2];
+
+            mpu9250.readGyroData(gyroCount);  // Read the x/y/z adc values
+            // Calculate the gyro value into actual degrees per second
+            gx = (float)gyroCount[0]*gRes - gyroBias[0];  // get actual gyro value, this depends on scale being set
+            gy = (float)gyroCount[1]*gRes - gyroBias[1];
+            gz = (float)gyroCount[2]*gRes - gyroBias[2];
+
+            mpu9250.readMagData(magCount);  // Read the x/y/z adc values
+            // Calculate the magnetometer values in milliGauss
+            // Include factory calibration per data sheet and user environmental corrections
+            mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0];  // get actual magnetometer value, this depends on scale being set
+            my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];
+            mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2];
+        }
+
+        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++;
+
+//    if(lastUpdate - firstUpdate > 10000000.0f) {
+//     beta = 0.04;  // decrease filter gain after stabilized
+//     zeta = 0.015; // increasey bias drift gain after stabilized
+//   }
+
+        // Pass gyro rate as rad/s
+        mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f,  my,  mx, mz);
+        //mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
+
+        // Serial print and/or display at 0.5 s rate independent of data rates
+        delt_t = t.read_ms() - _count;
+        if (delt_t > 50) { // 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("gx = %f", mx);
+            pc.printf(" gy = %f", my);
+            pc.printf(" gz = %f  mG\n\r", mz);*/
+
+            tempCount = mpu9250.readTempData();  // Read the adc values
+            temperature = ((float) tempCount) / 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]);*/
+
+            /*    lcd.clear();
+                lcd.printString("MPU9250", 0, 0);
+                lcd.printString("x   y   z", 0, 1);
+                sprintf(buffer, "%d %d %d mg", (int)(1000.0f*ax), (int)(1000.0f*ay), (int)(1000.0f*az));
+                lcd.printString(buffer, 0, 2);
+                sprintf(buffer, "%d %d %d deg/s", (int)gx, (int)gy, (int)gz);
+                lcd.printString(buffer, 0, 3);
+                sprintf(buffer, "%d %d %d mG", (int)mx, (int)my, (int)mz);
+                lcd.printString(buffer, 0, 4);
+             */
+            // 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]);
+            pitch *= 180.0f / PI;
+            yaw   *= 180.0f / PI;
+            yaw   -= 2.93f; // Declination at 8572 Berg TG: +2° 56'
+            roll  *= 180.0f / PI;
+
+            pc.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 imuSetup()
+{
+    read_imu_isrunning = true;
+    //Set up I2C
+    i2c.frequency(400000);  // use fast (400 kHz) I2C
+
+    pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock);
+
+    t.start();
+//  lcd.setBrightness(0.05);
+
+
+    // Read the WHO_AM_I register, this is a good test of communication
+    uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);  // Read WHO_AM_I register for MPU-9250
+    pc.printf("I AM 0x%x\n\r", whoami);
+    pc.printf("I SHOULD BE 0x71\n\r");
+
+    if (whoami == 0x71) { // WHO_AM_I should always be 0x68
+        pc.printf("MPU9250 WHO_AM_I is 0x%x\n\r", whoami);
+        pc.printf("MPU9250 is online...\n\r");
+        sprintf(buffer, "0x%x", whoami);
+        wait(1);
+
+        mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration
+        mpu9250.MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values
+        pc.printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]);
+        pc.printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]);
+        pc.printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]);
+        pc.printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]);
+        pc.printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]);
+        pc.printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]);
+        mpu9250.calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers
+        pc.printf("x gyro bias = %f\n\r", gyroBias[0]);
+        pc.printf("y gyro bias = %f\n\r", gyroBias[1]);
+        pc.printf("z gyro bias = %f\n\r", gyroBias[2]);
+        pc.printf("x accel bias = %f\n\r", accelBias[0]);
+        pc.printf("y accel bias = %f\n\r", accelBias[1]);
+        pc.printf("z accel bias = %f\n\r", accelBias[2]);
+        wait(2);
+        mpu9250.initMPU9250();
+        pc.printf("MPU9250 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
+        mpu9250.initAK8963(magCalibration);
+        pc.printf("AK8963 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer
+        pc.printf("Accelerometer full-scale range = %f  g\n\r", 2.0f*(float)(1<<Ascale));
+        pc.printf("Gyroscope full-scale range = %f  deg/s\n\r", 250.0f*(float)(1<<Gscale));
+        if(Mscale == 0) pc.printf("Magnetometer resolution = 14  bits\n\r");
+        if(Mscale == 1) pc.printf("Magnetometer resolution = 16  bits\n\r");
+        if(Mmode == 2) pc.printf("Magnetometer ODR = 8 Hz\n\r");
+        if(Mmode == 6) pc.printf("Magnetometer ODR = 100 Hz\n\r");
+        wait(1);
+    } else {
+        pc.printf("Could not connect to MPU9250: \n\r");
+        pc.printf("%#x \n",  whoami);
+        sprintf(buffer, "WHO_AM_I 0x%x", whoami);
+
+        while(1) {
+            // Loop forever if communication doesn't happen
+            pc.printf("commication not happening\n\r");
+        }
+    }
+
+    mpu9250.getAres(); // Get accelerometer sensitivity
+    mpu9250.getGres(); // Get gyro sensitivity
+    mpu9250.getMres(); // Get magnetometer sensitivity
+    pc.printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/aRes);
+    pc.printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/gRes);
+    pc.printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mRes);
+    magbias[0] = +470.;  // User environmental x-axis correction in milliGauss, should be automatically calculated
+    magbias[1] = +120.;  // User environmental x-axis correction in milliGauss
+    magbias[2] = +125.;  // User environmental x-axis correction in milliGauss
+}
+
+
+int main()
+{
+    pc.baud(9600);
+    imuSetup();
+    imuthread.start(readIMU);
+
+    // Request the shared queue
+    EventQueue *queue = mbed_event_queue();
+    printf("Starting in context %p\r\n", Thread::gettid());
+
+    // The 'rise' handler will execute in IRQ context
+    sw.rise(queue->event(rise_handler));
+    // The 'fall' handler will execute in the context of the shared queue (actually the main thread)
+    sw.fall(queue->event(fall_handler));
+    // Setup complete, so we now dispatch the shared queue from main
+    queue->dispatch_forever();
+}
\ No newline at end of file