Revision 3:bf624b3ae5b9, committed 2018-10-24

Comitter:

hisyamfs

Date:

Wed Oct 24 12:37:42 2018 +0000

Parent:

2:4e59a37182df

Commit message:

fork https://os.mbed.com/users/onehorse/code/MPU9250AHRS/ buat mpu 9255

Changed in this revision

diff -r 4e59a37182df -r bf624b3ae5b9 MPU9250.h
--- a/MPU9250.h	Tue Aug 05 01:37:23 2014 +0000
+++ b/MPU9250.h	Wed Oct 24 12:37:42 2018 +0000
@@ -190,7 +190,7 @@
 float aRes, gRes, mRes;      // scale resolutions per LSB for the sensors
 
 //Set up I2C, (SDA,SCL)
-I2C i2c(I2C_SDA, I2C_SCL);
+I2C i2c(D14, D15);
 
 DigitalOut myled(LED1);
     
@@ -625,7 +625,7 @@
 // Configure the accelerometer for self-test
    writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g
    writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
-   delay(25); // Delay a while to let the device stabilize
+   wait(25); // Delay a while to let the device stabilize
 
   for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer
   
@@ -648,7 +648,7 @@
  // Configure the gyro and accelerometer for normal operation
    writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00);
    writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);
-   delay(25); // Delay a while to let the device stabilize
+   wait(25); // Delay a while to let the device stabilize
    
    // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg
    selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results

diff -r 4e59a37182df -r bf624b3ae5b9 N5110.lib
--- a/N5110.lib	Tue Aug 05 01:37:23 2014 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +0,0 @@
-http://mbed.org/users/onehorse/code/Adfs/#28c629d0b0d0

diff -r 4e59a37182df -r bf624b3ae5b9 ST_401_84MHZ.lib
--- a/ST_401_84MHZ.lib	Tue Aug 05 01:37:23 2014 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +0,0 @@
-http://mbed.org/users/dreschpe/code/ST_401_84MHZ/#b9343c8b85ec

diff -r 4e59a37182df -r bf624b3ae5b9 main.cpp
--- a/main.cpp	Tue Aug 05 01:37:23 2014 +0000
+++ b/main.cpp	Wed Oct 24 12:37:42 2018 +0000
@@ -1,17 +1,17 @@
 /* MPU9250 Basic Example Code
  by: Kris Winer
  date: April 1, 2014
- license: Beerware - Use this code however you'd like. If you 
+ 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 
+
+ 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
@@ -19,112 +19,87 @@
  SDA ----------------------- A4
  SCL ----------------------- A5
  GND ---------------------- GND
- 
- Note: The MPU9250 is an I2C sensor and uses the Arduino Wire library. 
+
+ 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"
-#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;
 char buffer[14];
 
-   MPU9250 mpu9250;
-   
-   Timer t;
-
-   Serial pc(USBTX, USBRX); // tx, rx
+MPU9250 mpu9250;
+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();
+    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 = 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");
-    lcd.clear();
-    lcd.printString("MPU9250 is", 0, 0);
-    sprintf(buffer, "0x%x", whoami);
-    lcd.printString(buffer, 0, 1);
-    lcd.printString("shoud be 0x71", 0, 2);  
-    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);
- 
-    lcd.clear();
-    lcd.printString("MPU9250", 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
+    // 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 0x73\n\r");
+
+    if (whoami == 0x73) { // 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");
+//        lcd.clear();
+//        lcd.printString("MPU9250 is", 0, 0);
+        sprintf(buffer, "0x%x", whoami);
+//        lcd.printString(buffer, 0, 1);
+//        lcd.printString("shoud be 0x71", 0, 2);
+        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);
+
+//        lcd.clear();
+//        lcd.printString("MPU9250", 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
     }
 
     mpu9250.getAres(); // Get accelerometer sensitivity
@@ -137,118 +112,114 @@
     magbias[1] = +120.;  // User environmental x-axis correction in milliGauss
     magbias[2] = +125.;  // User environmental x-axis correction in milliGauss
 
- while(1) {
-  
-  // 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
+    while(1) {
+        // 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];
+        }
 
-    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++;
-    
+        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);
+//   }
+
+        // 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 2 s rate independent of data rates
+        delt_t = t.read_ms() - count;
+        if (delt_t > 2000) { // update LCD once per half-second independent of read rate
 
-    // 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("ax = %f", 1000*ax); 
-    pc.printf(" ay = %f", 1000*ay); 
-    pc.printf(" az = %f  mg\n\r", 1000*az); 
+            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("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   -= 13.8f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04
-    roll  *= 180.0f / PI;
+            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]);
 
-    pc.printf("Yaw, Pitch, Roll: %f %f %f\n\r", yaw, pitch, roll);
-    pc.printf("average rate = %f\n\r", (float) sumCount/sum);
+            /*    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   -= 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(); 
+
+            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();
+            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;
+        }
     }
-    sum = 0;
-    sumCount = 0; 
-}
-}
- 
- }
\ No newline at end of file
+
+}
\ No newline at end of file

diff -r 4e59a37182df -r bf624b3ae5b9 mbed.bld
--- a/mbed.bld	Tue Aug 05 01:37:23 2014 +0000
+++ b/mbed.bld	Wed Oct 24 12:37:42 2018 +0000
@@ -1,1 +1,1 @@
-http://mbed.org/users/mbed_official/code/mbed/builds/0b3ab51c8877
\ No newline at end of file
+https://os.mbed.com/users/mbed_official/code/mbed/builds/e95d10626187
\ No newline at end of file