#include #include //Declaring some global variables int gyro_x, gyro_y, gyro_z = 0; long gyro_x_cal, gyro_y_cal, gyro_z_cal = 0.0; boolean set_gyro_angles; long acc_x, acc_y, acc_z, acc_total_vector = 0.0; float angle_roll_acc, angle_pitch_acc = 0.0; float angle_pitch, angle_roll = 0.0; int angle_pitch_buffer, angle_roll_buffer = 0; float angle_pitch_output, angle_roll_output = 0.0; long loop_timer = 0.0; int temp = 0; AF_DCMotor motor1(1); AF_DCMotor motor2(2); AF_DCMotor motor3(3); AF_DCMotor motor4(4); void setup() { Wire.begin(); //Start I2C as master setup_mpu_6050_registers(); //Setup the registers of the MPU-6050 for (int cal_int = 0; cal_int < 1000 ; cal_int ++) { //Read the raw acc and gyro data from the MPU-6050 for 1000 times read_mpu_6050_data(); gyro_x_cal += gyro_x; //Add the gyro x offset to the gyro_x_cal variable gyro_y_cal += gyro_y; //Add the gyro y offset to the gyro_y_cal variable gyro_z_cal += gyro_z; //Add the gyro z offset to the gyro_z_cal variable delay(3); //Delay 3us to have 250Hz for-loop motor1.setSpeed(200); motor2.setSpeed(200); motor3.setSpeed(200); motor4.setSpeed(200); } // divide by 1000 to get avarage offset gyro_x_cal /= 1000; gyro_y_cal /= 1000; gyro_z_cal /= 1000; Serial.begin(9600); loop_timer = micros(); //Reset the loop timer } void loop() { read_mpu_6050_data(); //Subtract the offset values from the raw gyro values gyro_x -= gyro_x_cal; gyro_y -= gyro_y_cal; gyro_z -= gyro_z_cal; //Gyro angle calculations . Note 0.0000611 = 1 / (250Hz x 65.5) angle_pitch += gyro_x * 0.0000611; //Calculate the traveled pitch angle and add this to the angle_pitch variable angle_roll += gyro_y * 0.0000611; //Calculate the traveled roll angle and add this to the angle_roll variable //0.000001066 = 0.0000611 * (3.142(PI) / 180degr) The Arduino sin function is in radians angle_pitch += angle_roll * sin(gyro_z * 0.000001066); //If the IMU has yawed transfer the roll angle to the pitch angel angle_roll -= angle_pitch * sin(gyro_z * 0.000001066); //If the IMU has yawed transfer the pitch angle to the roll angel //Accelerometer angle calculations acc_total_vector = sqrt((acc_x * acc_x) + (acc_y * acc_y) + (acc_z * acc_z)); //Calculate the total accelerometer vector //57.296 = 1 / (3.142 / 180) The Arduino asin function is in radians angle_pitch_acc = asin((float)acc_y / acc_total_vector) * 57.296; //Calculate the pitch angle angle_roll_acc = asin((float)acc_x / acc_total_vector) * -57.296; //Calculate the roll angle angle_pitch_acc -= 0.0; //Accelerometer calibration value for pitch angle_roll_acc -= 0.0; //Accelerometer calibration value for roll if (set_gyro_angles) { //If the IMU is already started angle_pitch = angle_pitch * 0.9996 + angle_pitch_acc * 0.0004; //Correct the drift of the gyro pitch angle with the accelerometer pitch angle angle_roll = angle_roll * 0.9996 + angle_roll_acc * 0.0004; //Correct the drift of the gyro roll angle with the accelerometer roll angle } else { //At first start angle_pitch = angle_pitch_acc; //Set the gyro pitch angle equal to the accelerometer pitch angle angle_roll = angle_roll_acc; //Set the gyro roll angle equal to the accelerometer roll angle set_gyro_angles = true; //Set the IMU started flag } //To dampen the pitch and roll angles a complementary filter is used angle_pitch_output = angle_pitch_output * 0.9 + angle_pitch_acc * 0.1; //Take 90% of the output pitch value and add 10% of the raw pitch value angle_roll_output = angle_roll_output * 0.9 + angle_roll_acc * 0.1; //Take 90% of the output roll value and add 10% of the raw roll value Serial.print(" | Angle = "); Serial.println(angle_pitch_output); while (micros() - loop_timer < 10); {//Wait until the loop_timer reaches 4000us (250Hz) before starting the next loop loop_timer = micros();//Reset the loop timer } if (angle_pitch_output > 3) { motor1.run(FORWARD); motor2.run(FORWARD); motor3.run(FORWARD); motor4.run(FORWARD); } else if (angle_pitch_output < -3) { motor1.run(BACKWARD); motor2.run(BACKWARD); motor3.run(BACKWARD); motor4.run(BACKWARD); } else if (angle_pitch_output >= -3 || angle_pitch_output <= 3) { motor1.run(RELEASE); motor2.run(RELEASE); motor3.run(RELEASE); motor4.run(RELEASE); } } void setup_mpu_6050_registers() { //Activate the MPU-6050 Wire.beginTransmission(0x68); //Start communicating with the MPU-6050 Wire.write(0x6B); //Send the requested starting register Wire.write(0x00); //Set the requested starting register Wire.endTransmission(); //Configure the accelerometer (+/-8g) Wire.beginTransmission(0x68); //Start communicating with the MPU-6050 Wire.write(0x1C); //Send the requested starting register Wire.write(0x10); //Set the requested starting register Wire.endTransmission(); //Configure the gyro (500dps full scale) Wire.beginTransmission(0x68); //Start communicating with the MPU-6050 Wire.write(0x1B); //Send the requested starting register Wire.write(0x08); //Set the requested starting register Wire.endTransmission(); } void read_mpu_6050_data() { //Subroutine for reading the raw gyro and accelerometer data Wire.beginTransmission(0x68); //Start communicating with the MPU-6050 Wire.write(0x3B); //Send the requested starting register Wire.endTransmission(); //End the transmission Wire.requestFrom(0x68, 14); //Request 14 bytes from the MPU-6050 while (Wire.available() < 14); //Wait until all the bytes are received acc_x = Wire.read() << 8 | Wire.read(); acc_y = Wire.read() << 8 | Wire.read(); acc_z = Wire.read() << 8 | Wire.read(); temp = Wire.read() << 8 | Wire.read(); gyro_x = Wire.read() << 8 | Wire.read(); gyro_y = Wire.read() << 8 | Wire.read(); gyro_z = Wire.read() << 8 | Wire.read(); }