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Class of MPU9250
Dependencies: AHRS_fillter mbed
Fork of MPU9250AHRS by
Diff: main.cpp
- Revision:
- 3:3e04c1c03cab
- Parent:
- 1:71c319f03fda
- Child:
- 4:1e5db958fd1b
diff -r 4e59a37182df -r 3e04c1c03cab main.cpp --- a/main.cpp Tue Aug 05 01:37:23 2014 +0000 +++ b/main.cpp Fri Dec 18 12:59:56 2015 +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 @@ -19,18 +19,18 @@ 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" + +//#include "ST_F401_84MHZ.h" //F401_init84 myinit(0); #include "mbed.h" #include "MPU9250.h" -#include "N5110.h" +//#include "N5110.h" // Using NOKIA 5110 monochrome 84 x 48 pixel display // pin 9 - Serial clock out (SCLK) @@ -44,87 +44,106 @@ uint32_t sumCount = 0; char buffer[14]; - MPU9250 mpu9250; - - Timer t; +MPU9250 mpu9250; + +Timer t; - Serial pc(USBTX, USBRX); // tx, rx +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); +float xmax = -4914.0f; +float xmin = 4914.0f; - // 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); - +float ymax = -4914.0; +float ymin = 4914.0f; + +float zmax = -4914.0; +float zmin = 4914.0f; - +float Xsf,Ysf; +float Xoff,Yoff; + + +//InterruptIn event(PC_13); +DigitalIn enable(PC_13); + int main() { - pc.baud(9600); + + pc.baud(115200); + + //Set up I2C + i2c.frequency(400000); // use fast (400 kHz) I2C - //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.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 + + //mpu9250.resetMPU9250(); + // 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 + + whoami = mpu9250.readByte(AK8963_ADDRESS, WHO_AM_I_AK8963); // Read WHO_AM_I register for MPU-9250 + pc.printf("I AM 0x%x\n\r", whoami); + pc.printf("I SHOULD BE 0x48\n\r"); + if(whoami != 0x48) { + while(1); + } + 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 @@ -133,122 +152,215 @@ 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 + // pc.printf("Magnetometer[0] adjust sensittivity is %f \n\r", magCalibration[0]); + // pc.printf("Magnetometer[1] adjust sensittivity is %f \n\r", magCalibration[1]); + // pc.printf("Magnetometer[2] adjust sensittivity is %f \n\r", magCalibration[2]); + // mRes = 10.*1229./4096.; // Conversion from 1229 microTesla full scale (4096) to 12.29 Gauss full scale + //mRes = 10.*1229./32760.; + // 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 + + // 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 + + + + pc.printf("START scan mag\n\r\n\r\n\r"); + //wait(1); + for(int i=0; i<800; i++) { + mpu9250.readMagData(magCount); + + if(magCount[0]<xmin) + xmin = magCount[0]; + if(magCount[0]>xmax) + xmax = magCount[0]; - 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 + if(magCount[1]<ymin) + ymin = magCount[1]; + if(magCount[1]>ymax) + ymax = magCount[1]; + + if(magCount[2]<zmin) + zmin = magCount[2]; + if(mz>zmax) + zmax = mz; + + + + wait_ms(10); + } + pc.printf("FINISH scan\r\n\r\n"); + pc.printf("Mx Max= %f Min= %f\n\r",xmax,xmin); + pc.printf("My Max= %f Min= %f\n\r",ymax,ymin); + pc.printf("Mz Max= %f Min= %f\n\r",zmax,zmin); + + + + magbias[0] = ((xmax-xmin)/2.0f - xmax); // User environmental x-axis correction in milliGauss, should be automatically calculated + magbias[1] = ((ymax-ymin)/2.0f - ymax); // User environmental x-axis correction in milliGauss + magbias[2] = ((zmax-zmin)/2.0f - zmax); // User environmental x-axis correction in milliGauss + + //magbias[0] = (xmin-xmax)/2.0f; // User environmental x-axis correction in milliGauss, should be automatically calculated + //magbias[1] = (ymin-ymax)/2.0f; // User environmental x-axis correction in milliGauss + //magbias[2] = (zmin-zmax)/2.0f; // User environmental x-axis correction in milliGauss + pc.printf("mag[0] %f",magbias[0]); + pc.printf("mag[1] %f",magbias[1]); + pc.printf("mag[2] %f\n\r",magbias[2]); + // resalt = atan(magY+((yMin-yMax)/2),magX+(xMin-xMax)/2))*180/PI; - 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++; - + + 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 + /* if(magCount[0]<xmin) + xmin = magCount[0]; + if(magCount[0]>xmax) + xmax = magCount[0]; + + if(magCount[1]<ymin) + ymin = magCount[1]; + if(magCount[1]>ymax) + ymax = magCount[1]; + + if(magCount[2]<zmin) + zmin = magCount[2]; + if(mz>zmax) + zmax = mz; + wait_ms(1); + */ + // pc.printf("FINISH scan\r\n\r\n"); + + 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]; + + // mx = (float)magCount[0]*1.499389499f - magbias[0]; // get actual magnetometer value, this depends on scale being set + // my = (float)magCount[1]*1.499389499f - magbias[1]; + // mz = (float)magCount[2]*1.499389499f - 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); +// } + + // 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 > 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); - // 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("gx = %f", gx); + pc.printf(" gy = %f", gy); + pc.printf(" gz = %f deg/s\n\r", gz); + + pc.printf("mx = %f", mx); + pc.printf(" my = %f", my); + pc.printf(" mz = %f mG\n\r", mz); - pc.printf("ax = %f", 1000*ax); - pc.printf(" ay = %f", 1000*ay); - pc.printf(" az = %f mg\n\r", 1000*az); + whoami = mpu9250.readByte(AK8963_ADDRESS, AK8963_ST2); // Read WHO_AM_I register for MPU-9250 + // pc.printf("I AM 0x%x\n\r", whoami); pc.printf("I SHOULD BE 0x10\n\r"); + if(whoami == 0x14) { + pc.printf("I AM 0x%x\n\r", whoami); + while(1); + } + + + 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); + // 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]); + + float Xh = mx*cos(pitch)+my*sin(roll)*sin(pitch)-mz*cos(roll)*sin(pitch); + float Yh = my*cos(roll)+mz*sin(roll); + + float yawmag = atan2(Yh,Xh)+PI; + pc.printf("Xh= %f Yh= %f ",Xh,Yh); + pc.printf("Yaw[mag]= %f\n\r",yawmag*180.0f/PI); + + + + pitch *= 180.0f / PI; + yaw *= 180.0f / PI; + yaw += 180.0f; // 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