Yaakov Husarsky / Mbed OS Nucleo_gyro

use nucleo with gyro sensor to output serially x,y,z,pitch,yaw,roll data

Dependencies:   Nucleo_ticker

main.cpp@2:ba7945a8d1c6, 2021-06-01 (annotated)

Committer:
parahoid
Date:
Tue Jun 01 16:47:31 2021 +0000
Revision:
2:ba7945a8d1c6
Parent:
0:573c02b712fe 
Program to connect to mpu6050 and display x,y,z and pitch,roll,yaw

Who changed what in which revision?

UserRevisionLine numberNew contents of line
tulanthoar 0:573c02b712fe 1 #include "mbed.h"
parahoid 2:ba7945a8d1c6 2 #include "MPU6050.h"
tulanthoar 0:573c02b712fe 3
parahoid 2:ba7945a8d1c6 4 /*
parahoid 2:ba7945a8d1c6 5 Hardware setup:
parahoid 2:ba7945a8d1c6 6 MPU6050 Breakout --------- Arduino
parahoid 2:ba7945a8d1c6 7 3.3V --------------------- 3.3V
parahoid 2:ba7945a8d1c6 8 SDA ----------------------- A4
parahoid 2:ba7945a8d1c6 9 SCL ----------------------- A5
parahoid 2:ba7945a8d1c6 10 GND ---------------------- GND
parahoid 2:ba7945a8d1c6 11
parahoid 2:ba7945a8d1c6 12 Note: The MPU6050 is an I2C sensor and uses the Arduino Wire library.
parahoid 2:ba7945a8d1c6 13 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.
parahoid 2:ba7945a8d1c6 14 We have disabled the internal pull-ups used by the Wire library in the Wire.h/twi.c utility file.
parahoid 2:ba7945a8d1c6 15 We are also using the 400 kHz fast I2C mode by setting the TWI_FREQ to 400000L /twi.h utility file.
parahoid 2:ba7945a8d1c6 16 */
tulanthoar 0:573c02b712fe 17
parahoid 2:ba7945a8d1c6 18 MPU6050 mpu6050;
parahoid 2:ba7945a8d1c6 19 Timer t;
parahoid 2:ba7945a8d1c6 20 Serial pc(USBTX, USBRX); // tx, rx
parahoid 2:ba7945a8d1c6 21 float sum = 0;
parahoid 2:ba7945a8d1c6 22 uint32_t sumCount = 0;
parahoid 2:ba7945a8d1c6 23
parahoid 2:ba7945a8d1c6 24 void main ()
parahoid 2:ba7945a8d1c6 25 {
parahoid 2:ba7945a8d1c6 26 pc.baud(9600);
tulanthoar 0:573c02b712fe 27
parahoid 2:ba7945a8d1c6 28 //Set up I2C
parahoid 2:ba7945a8d1c6 29 i2c.frequency(400000); // use fast (400 kHz) I2C
parahoid 2:ba7945a8d1c6 30
parahoid 2:ba7945a8d1c6 31 t.start();
parahoid 2:ba7945a8d1c6 32 // Read the WHO_AM_I register, this is a good test of communication
parahoid 2:ba7945a8d1c6 33 uint8_t whoami = mpu6050.readByte(MPU6050_ADDRESS, WHO_AM_I_MPU6050); // Read WHO_AM_I register for MPU-6050
parahoid 2:ba7945a8d1c6 34 pc.printf("I AM 0x%x\n", whoami);
parahoid 2:ba7945a8d1c6 35 pc.printf("I SHOULD BE 0x68\n");
parahoid 2:ba7945a8d1c6 36
parahoid 2:ba7945a8d1c6 37 if (whoami == 0x68) // WHO_AM_I should always be 0x68
parahoid 2:ba7945a8d1c6 38 {
parahoid 2:ba7945a8d1c6 39 pc.printf("MPU6050 is online")
parahoid 2:ba7945a8d1c6 40 wait(1);
parahoid 2:ba7945a8d1c6 41 mpu6050.MPU6050SelfTest(SelfTest); // Start by performing self test and reporting values
parahoid 2:ba7945a8d1c6 42 pc.printf("x-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[0]); pc.printf("% of factory value \n\r");
parahoid 2:ba7945a8d1c6 43 pc.printf("y-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[1]); pc.printf("% of factory value \n\r");
parahoid 2:ba7945a8d1c6 44 pc.printf("z-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[2]); pc.printf("% of factory value \n\r");
parahoid 2:ba7945a8d1c6 45 pc.printf("x-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[3]); pc.printf("% of factory value \n\r");
parahoid 2:ba7945a8d1c6 46 pc.printf("y-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[4]); pc.printf("% of factory value \n\r");
parahoid 2:ba7945a8d1c6 47 pc.printf("z-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[5]); pc.printf("% of factory value \n\r");
parahoid 2:ba7945a8d1c6 48 wait(1);
parahoid 2:ba7945a8d1c6 49 if(SelfTest[0] < 1.0f && SelfTest[1] < 1.0f && SelfTest[2] < 1.0f && SelfTest[3] < 1.0f && SelfTest[4] < 1.0f && SelfTest[5] < 1.0f)
parahoid 2:ba7945a8d1c6 50 {
parahoid 2:ba7945a8d1c6 51 mpu6050.resetMPU6050(); // Reset registers to default in preparation for device calibration
parahoid 2:ba7945a8d1c6 52 mpu6050.calibrateMPU6050(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers
parahoid 2:ba7945a8d1c6 53 mpu6050.initMPU6050(); pc.printf("MPU6050 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
parahoid 2:ba7945a8d1c6 54 wait(2);
parahoid 2:ba7945a8d1c6 55 }
parahoid 2:ba7945a8d1c6 56 else
parahoid 2:ba7945a8d1c6 57 {
parahoid 2:ba7945a8d1c6 58 pc.printf("Device did not the pass self-test!\n");
parahoid 2:ba7945a8d1c6 59 }
parahoid 2:ba7945a8d1c6 60 }
parahoid 2:ba7945a8d1c6 61 else
parahoid 2:ba7945a8d1c6 62 {
parahoid 2:ba7945a8d1c6 63 pc.printf("Could not connect to MPU6050: \n");
parahoid 2:ba7945a8d1c6 64 pc.printf("%#x \n", whoami);
parahoid 2:ba7945a8d1c6 65 while(true) ; // Loop forever if communication doesn't happen
parahoid 2:ba7945a8d1c6 66 }
parahoid 2:ba7945a8d1c6 67 while(true) {
parahoid 2:ba7945a8d1c6 68 // If data ready bit set, all data registers have new data
parahoid 2:ba7945a8d1c6 69 if(mpu6050.readByte(MPU6050_ADDRESS, INT_STATUS) & 0x01) // check if data ready interrupt
parahoid 2:ba7945a8d1c6 70 {
parahoid 2:ba7945a8d1c6 71 mpu6050.readAccelData(accelCount); // Read the x/y/z adc values
parahoid 2:ba7945a8d1c6 72 mpu6050.getAres();
parahoid 2:ba7945a8d1c6 73
parahoid 2:ba7945a8d1c6 74 // Now we'll calculate the accleration value into actual g's
parahoid 2:ba7945a8d1c6 75 ax = (float)accelCount[0]*aRes - accelBias[0]; // get actual g value, this depends on scale being set
parahoid 2:ba7945a8d1c6 76 ay = (float)accelCount[1]*aRes - accelBias[1];
parahoid 2:ba7945a8d1c6 77 az = (float)accelCount[2]*aRes - accelBias[2];
parahoid 2:ba7945a8d1c6 78
parahoid 2:ba7945a8d1c6 79 mpu6050.readGyroData(gyroCount); // Read the x/y/z adc values
parahoid 2:ba7945a8d1c6 80 mpu6050.getGres();
parahoid 2:ba7945a8d1c6 81
parahoid 2:ba7945a8d1c6 82 // Calculate the gyro value into actual degrees per second
parahoid 2:ba7945a8d1c6 83 gx = (float)gyroCount[0]*gRes; // - gyroBias[0]; // get actual gyro value, this depends on scale being set
parahoid 2:ba7945a8d1c6 84 gy = (float)gyroCount[1]*gRes; // - gyroBias[1];
parahoid 2:ba7945a8d1c6 85 gz = (float)gyroCount[2]*gRes; // - gyroBias[2];
parahoid 2:ba7945a8d1c6 86
parahoid 2:ba7945a8d1c6 87 tempCount = mpu6050.readTempData(); // Read the x/y/z adc values
parahoid 2:ba7945a8d1c6 88 temperature = (tempCount) / 340. + 36.53; // Temperature in degrees Centigrade
parahoid 2:ba7945a8d1c6 89 }
parahoid 2:ba7945a8d1c6 90 Now = t.read_us();
parahoid 2:ba7945a8d1c6 91 deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
parahoid 2:ba7945a8d1c6 92 lastUpdate = Now;
parahoid 2:ba7945a8d1c6 93
parahoid 2:ba7945a8d1c6 94 sum += deltat;
parahoid 2:ba7945a8d1c6 95 sumCount++;
parahoid 2:ba7945a8d1c6 96
parahoid 2:ba7945a8d1c6 97 if(lastUpdate - firstUpdate > 10000000.0f) {
parahoid 2:ba7945a8d1c6 98 beta = 0.04; // decrease filter gain after stabilized
parahoid 2:ba7945a8d1c6 99 zeta = 0.015; // increasey bias drift gain after stabilized
parahoid 2:ba7945a8d1c6 100 }
parahoid 2:ba7945a8d1c6 101
parahoid 2:ba7945a8d1c6 102 mpu6050.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f);
parahoid 2:ba7945a8d1c6 103 // Serial print and/or display at 0.5 s rate independent of data rates
parahoid 2:ba7945a8d1c6 104 delt_t = t.read_ms() - count;
parahoid 2:ba7945a8d1c6 105
parahoid 2:ba7945a8d1c6 106 if (delt_t > 500) // update once per half-second independent of read rate
parahoid 2:ba7945a8d1c6 107 {
parahoid 2:ba7945a8d1c6 108 /*
parahoid 2:ba7945a8d1c6 109 pc.printf("ax = %f", 1000*ax);
parahoid 2:ba7945a8d1c6 110 pc.printf(" ay = %f", 1000*ay);
parahoid 2:ba7945a8d1c6 111 pc.printf(" az = %f mg\n\r", 1000*az);
parahoid 2:ba7945a8d1c6 112
parahoid 2:ba7945a8d1c6 113 pc.printf("gx = %f", gx);
parahoid 2:ba7945a8d1c6 114 pc.printf(" gy = %f", gy);
parahoid 2:ba7945a8d1c6 115 pc.printf(" gz = %f deg/s\n\r", gz);
parahoid 2:ba7945a8d1c6 116
parahoid 2:ba7945a8d1c6 117 pc.printf(" temperature = %f C\n\r", temperature);
parahoid 2:ba7945a8d1c6 118
parahoid 2:ba7945a8d1c6 119 pc.printf("q0 = %f\n\r", q[0]);
parahoid 2:ba7945a8d1c6 120 pc.printf("q1 = %f\n\r", q[1]);
parahoid 2:ba7945a8d1c6 121 pc.printf("q2 = %f\n\r", q[2]);
parahoid 2:ba7945a8d1c6 122 pc.printf("q3 = %f\n\r", q[3]);
parahoid 2:ba7945a8d1c6 123 */
parahoid 2:ba7945a8d1c6 124 // Define output variables from updated quaternion---these are Tait-Bryan angles, commonly used in aircraft orientation.
parahoid 2:ba7945a8d1c6 125 // In this coordinate system, the positive z-axis is down toward Earth.
parahoid 2:ba7945a8d1c6 126 // 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.
parahoid 2:ba7945a8d1c6 127 // Pitch is angle between sensor x-axis and Earth ground plane, toward the Earth is positive, up toward the sky is negative.
parahoid 2:ba7945a8d1c6 128 // Roll is angle between sensor y-axis and Earth ground plane, y-axis up is positive roll.
parahoid 2:ba7945a8d1c6 129 // These arise from the definition of the homogeneous rotation matrix constructed from quaternions.
parahoid 2:ba7945a8d1c6 130 // Tait-Bryan angles as well as Euler angles are non-commutative; that is, the get the correct orientation the rotations must be
parahoid 2:ba7945a8d1c6 131 // applied in the correct order which for this configuration is yaw, pitch, and then roll.
parahoid 2:ba7945a8d1c6 132 // For more see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles which has additional links.
parahoid 2:ba7945a8d1c6 133 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]);
parahoid 2:ba7945a8d1c6 134 pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2]));
parahoid 2:ba7945a8d1c6 135 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]);
parahoid 2:ba7945a8d1c6 136 pitch *= 180.0f / PI;
parahoid 2:ba7945a8d1c6 137 yaw *= 180.0f / PI;
parahoid 2:ba7945a8d1c6 138 roll *= 180.0f / PI;
parahoid 2:ba7945a8d1c6 139 // pc.printf("Yaw, Pitch, Roll: \n\r");
parahoid 2:ba7945a8d1c6 140 // pc.printf("%f", yaw);
parahoid 2:ba7945a8d1c6 141 // pc.printf(", ");
parahoid 2:ba7945a8d1c6 142 // pc.printf("%f", pitch);
parahoid 2:ba7945a8d1c6 143 // pc.printf(", ");
parahoid 2:ba7945a8d1c6 144 // pc.printf("%f\n\r", roll);
parahoid 2:ba7945a8d1c6 145 // pc.printf("average rate = "); pc.printf("%f", (sumCount/sum)); pc.printf(" Hz\n\r");
parahoid 2:ba7945a8d1c6 146
parahoid 2:ba7945a8d1c6 147 pc.printf("X, Y, Z, Yaw, Pitch, Roll: %f %f %f %f %f %f\n\r", gx, gy, gz, yaw, pitch, roll);
parahoid 2:ba7945a8d1c6 148 //pc.printf("average rate = %f\n\r", (float) sumCount/sum);
parahoid 2:ba7945a8d1c6 149
parahoid 2:ba7945a8d1c6 150 count = t.read_ms();
parahoid 2:ba7945a8d1c6 151 sum = 0;
parahoid 2:ba7945a8d1c6 152 sumCount = 0;
parahoid 2:ba7945a8d1c6 153 }
tulanthoar 0:573c02b712fe 154 }
tulanthoar 0:573c02b712fe 155 }