TurtleBot
IMU for turtle robot project
Dependencies: mbed
Diff: main.cpp
- Revision:
- 0:2e5e65a6fb30
- Child:
- 1:71c319f03fda
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sun Jun 29 22:02:30 2014 +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"
+#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
+
+ // 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 = 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.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
+ 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) {
+
+ // 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 > 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 = 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("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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