int main()
{
pc.baud(9600);
//Set up I2C
i2c.frequency(400000); // use fast (400 kHz) I2C
t.start();
lcd.init();
lcd.setBrightness(0.05);
// Read the WHO_AM_I register, this is a good test of communication
uint8_t whoami = mpu6050.readByte(MPU6050_ADDRESS, WHO_AM_I_MPU6050); // Read WHO_AM_I register for MPU-6050
pc.printf("I AM 0x%x\n\r", whoami); pc.printf("I SHOULD BE 0x68\n\r");
if (whoami == 0x68) // WHO_AM_I should always be 0x68
{
pc.printf("MPU6050 is online...");
wait(1);
lcd.clear();
lcd.printString("MPU6050 OK", 0, 0);
mpu6050.MPU6050SelfTest(SelfTest); // Start by performing self test and reporting values
pc.printf("x-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[0]); pc.printf("% of factory value \n\r");
pc.printf("y-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[1]); pc.printf("% of factory value \n\r");
pc.printf("z-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[2]); pc.printf("% of factory value \n\r");
pc.printf("x-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[3]); pc.printf("% of factory value \n\r");
pc.printf("y-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[4]); pc.printf("% of factory value \n\r");
pc.printf("z-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[5]); pc.printf("% of factory value \n\r");
wait(1);
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)
{
mpu6050.resetMPU6050(); // Reset registers to default in preparation for device calibration
mpu6050.calibrateMPU6050(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers
mpu6050.initMPU6050(); pc.printf("MPU6050 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
lcd.clear();
lcd.printString("MPU6050", 0, 0);
lcd.printString("pass self test", 0, 1);
lcd.printString("initializing", 0, 2);
wait(2);
}
else
{
pc.printf("Device did not the pass self-test!\n\r");
lcd.clear();
lcd.printString("MPU6050", 0, 0);
lcd.printString("no pass", 0, 1);
lcd.printString("self test", 0, 2);
}
}
else
{
pc.printf("Could not connect to MPU6050: \n\r");
pc.printf("%#x \n", whoami);
lcd.clear();
lcd.printString("MPU6050", 0, 0);
lcd.printString("no connection", 0, 1);
lcd.printString("0x", 0, 2); lcd.setXYAddress(20, 2); lcd.printChar(whoami);
while(1) ; // Loop forever if communication doesn't happen
}
while(1) {
// If data ready bit set, all data registers have new data
if(mpu6050.readByte(MPU6050_ADDRESS, INT_STATUS) & 0x01) { // check if data ready interrupt
mpu6050.readAccelData(accelCount); // Read the x/y/z adc values
mpu6050.getAres();
// 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];
mpu6050.readGyroData(gyroCount); // Read the x/y/z adc values
mpu6050.getGres();
// 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];
tempCount = mpu6050.readTempData(); // Read the x/y/z adc values
temperature = (tempCount) / 340. + 36.53; // Temperature in degrees Centigrade
}
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
mpu6050.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f);
// 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(" 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("MPU6050", 0, 0);
lcd.printString("x y z", 0, 1);
lcd.setXYAddress(0, 2); lcd.printChar((char)(1000*ax));
lcd.setXYAddress(20, 2); lcd.printChar((char)(1000*ay));
lcd.setXYAddress(40, 2); lcd.printChar((char)(1000*az)); lcd.printString("mg", 66, 2);
// 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;
roll *= 180.0f / PI;
// pc.printf("Yaw, Pitch, Roll: \n\r");
// pc.printf("%f", yaw);
// pc.printf(", ");
// pc.printf("%f", pitch);
// pc.printf(", ");
// pc.printf("%f\n\r", roll);
// pc.printf("average rate = "); pc.printf("%f", (sumCount/sum)); pc.printf(" Hz\n\r");
pc.printf("Yaw, Pitch, Roll: %f %f %f\n\r", yaw, pitch, roll);
pc.printf("average rate = %f\n\r", (float) sumCount/sum);
myled= !myled;
count = t.read_ms();
sum = 0;
sumCount = 0;
}
}
}
