Diff: main.cpp

Revision:

0:31cc139b7d1e

Child:

1:0158e4d78423

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+++ b/main.cpp	Sat Sep 10 14:15:19 2016 +0000
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+/* MPU9250 Basic Example Code
+ by: Kris Winer
+ date: April 1, 2014
+ license: Beerware - Use this code however you'd like. If you 
+ find it useful you can buy me a beer some time.
+ 
+ Demonstrate basic MPU-9250 functionality including parameterizing the register addresses, initializing the sensor, 
+ getting properly scaled accelerometer, gyroscope, and magnetometer data out. Added display functions to 
+ allow display to on breadboard monitor. Addition of 9 DoF sensor fusion using open source Madgwick and 
+ Mahony filter algorithms. Sketch runs on the 3.3 V 8 MHz Pro Mini and the Teensy 3.1.
+ 
+ SDA and SCL should have external pull-up resistors (to 3.3V).
+ 10k resistors are on the EMSENSR-9250 breakout board.
+ 
+ Hardware setup:
+ MPU9250 Breakout --------- Arduino
+ VDD ---------------------- 3.3V
+ VDDI --------------------- 3.3V
+ SDA ----------------------- A4
+ SCL ----------------------- A5
+ GND ---------------------- GND
+ 
+ Note: The MPU9250 is an I2C sensor and uses the Arduino Wire library. 
+ Because the sensor is not 5V tolerant, we are using a 3.3 V 8 MHz Pro Mini or a 3.3 V Teensy 3.1.
+ We have disabled the internal pull-ups used by the Wire library in the Wire.h/twi.c utility file.
+ We are also using the 400 kHz fast I2C mode by setting the TWI_FREQ  to 400000L /twi.h utility file.
+ */
+ 
+//#include "ST_F401_84MHZ.h" 
+//F401_init84 myinit(0);
+#include "mbed.h"
+#include "MPU9250.h"
+
+
+float sum = 0;
+uint32_t sumCount = 0;
+
+   MPU9250 mpu9250;
+   
+   Timer t;
+
+   Serial pc(USBTX, USBRX); // tx, rx
+
+volatile bool newData = false;
+
+InterruptIn isrPin(D12);   //k64 D12  dragon PD_0
+
+void mpuisr() {
+    newData=true;
+}
+        
+int main()
+{
+  pc.baud(9600);  
+
+  //Set up I2C
+  i2c.frequency(400000);  // use fast (400 kHz) I2C  
+  
+  pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock);   
+  
+  t.start();  
+  isrPin.rise(&mpuisr);      
+    
+  // 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 is online...\n\r");
+    wait(1);
+
+    
+    mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration
+    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(2);
+   }
+   else
+   {
+    pc.printf("Could not connect to MPU9250: \n\r");
+    pc.printf("%#x \n",  whoami);
+
+ 
+    while(1) ; // Loop forever if communication doesn't happen
+    }
+
+    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
+
+ while(1) {
+    static int readycnt=0;
+  // If intPin goes high, all data registers have new data
+  
+#if USE_ISR
+  if(newData) {
+    newData=false;
+    mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS);  //? need this with ISR
+#else
+    if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) {  // On interrupt, check if data ready interrupt
+#endif
+    readycnt++;
+    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
+   uint32_t us = t.read_us();
+  mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f,  my,  mx, mz);
+   us = t.read_us()-us;
+ // 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 > 500) { // update LCD once per half-second independent of read rate
+        pc.printf("readycnt %d us %d\n",readycnt,us);
+        readycnt=0;
+    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]);      
+
+    
+    
+  // 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   -= 13.8f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04
+    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);
+ 
+    myled= !myled;
+    count = t.read_ms(); 
+    sum = 0;
+    sumCount = 0; 
+}
+}
+ 
+ }
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