Diff: main.cpp

Revision:

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+++ b/main.cpp	Sun Jun 29 22:48:08 2014 +0000
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+/* MPU9150 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-9150 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:
+ MPU9150 Breakout --------- Arduino
+ VDD ---------------------- 3.3V
+ VDDI --------------------- 3.3V
+ SDA ----------------------- A4
+ SCL ----------------------- A5
+ GND ---------------------- GND
+ 
+ Note: The MPU9150 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 "MPU9150.h"
+#include "N5110.h"
+
+// Using NOKIA 5110 monochrome 84 x 48 pixel display
+// pin 9 - Serial clock out (SCLK)
+// pin 8 - Serial data out (DIN)
+// pin 7 - Data/Command select (D/C)
+// pin 5 - LCD chip select (CS)
+// pin 6 - LCD reset (RST)
+//Adafruit_PCD8544 display = Adafruit_PCD8544(9, 8, 7, 5, 6);
+
+float sum = 0;
+uint32_t sumCount = 0, mcount = 0;
+char buffer[14];
+
+   MPU9150 MPU9150;
+   
+   Timer t;
+
+   Serial pc(USBTX, USBRX); // tx, rx
+
+   //        VCC,   SCE,  RST,  D/C,  MOSI,S CLK, LED
+   N5110 lcd(PA_8, PB_10, PA_9, PA_6, PA_7, PA_5, PC_7);
+   
+
+        
+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();        
+  
+  lcd.init();
+//  lcd.setBrightness(0.05);
+  
+    
+  // Read the WHO_AM_I register, this is a good test of communication
+  uint8_t whoami = MPU9150.readByte(MPU9150_ADDRESS, WHO_AM_I_MPU9150);  // Read WHO_AM_I register for MPU-9250
+  pc.printf("I AM 0x%x\n\r", whoami); pc.printf("I SHOULD BE 0x68\n\r");
+  
+  if (whoami == 0x68) // WHO_AM_I should be 0x68
+  {  
+    pc.printf("MPU9150 WHO_AM_I is 0x%x\n\r", whoami);
+    pc.printf("MPU9150 is online...\n\r");
+    lcd.clear();
+    lcd.printString("MPU9150 is", 0, 0);
+    sprintf(buffer, "0x%x", whoami);
+    lcd.printString(buffer, 0, 1);
+    lcd.printString("shoud be 0x68", 0, 2);  
+    wait(1);
+    
+    MPU9150.MPU9150SelfTest(SelfTest);
+    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]);
+    wait(1);
+    MPU9150.resetMPU9150(); // Reset registers to default in preparation for device calibration
+    MPU9150.calibrateMPU9150(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(1);
+    MPU9150.initMPU9150(); 
+    pc.printf("MPU9150 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
+    MPU9150.initAK8975A(magCalibration);
+    pc.printf("AK8975 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer
+   }
+   else
+   {
+    pc.printf("Could not connect to MPU9150: \n\r");
+    pc.printf("%#x \n",  whoami);
+ 
+    lcd.clear();
+    lcd.printString("MPU9150", 0, 0);
+    lcd.printString("no connection", 0, 1);
+    sprintf(buffer, "WHO_AM_I 0x%x", whoami);
+    lcd.printString(buffer, 0, 2); 
+ 
+    while(1) ; // Loop forever if communication doesn't happen
+    }
+
+    uint8_t MagRate = 10; // set magnetometer read rate in Hz; 10 to 100 (max) Hz are reasonable values
+    MPU9150.getAres(); // Get accelerometer sensitivity
+    MPU9150.getGres(); // Get gyro sensitivity
+    mRes = 10.*1229./4096.; // Conversion from 1229 microTesla full scale (4096) to 12.29 Gauss full scale
+    // So far, magnetometer bias is calculated and subtracted here manually, should construct an algorithm to do it automatically
+    // like the gyro and accelerometer biases
+    magbias[0] = -5.;   // User environmental x-axis correction in milliGauss
+    magbias[1] = -95.;  // User environmental y-axis correction in milliGauss
+    magbias[2] = -260.; // User environmental z-axis correction in milliGauss
+ 
+
+ while(1) {
+  
+  // If intPin goes high, all data registers have new data
+  if(MPU9150.readByte(MPU9150_ADDRESS, INT_STATUS) & 0x01) {  // On interrupt, check if data ready interrupt
+
+    MPU9150.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];  
+   
+    MPU9150.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];   
+  
+    mcount++;
+    if (mcount > 200/MagRate) {  // this is a poor man's way of setting the magnetometer read rate (see below) 
+    MPU9150.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];   
+    mcount = 0;
+    }
+  }
+   
+    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
+//  MPU9150.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f,  my,  mx, mz);
+  MPU9150.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("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 = MPU9150.readTempData();  // Read the adc values
+    temperature = ((float) tempCount) / 340.0f + 36.53f; // 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("MPU9150", 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   -= 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);
+//    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; 
+}
+}
+ 
+ }
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