I am trying to get direct values from an MPU6050 while using a Nano. The code used called for the serial monitor baud rate to be 115200. Upon uploading, I was able to see the serial monitor print the rate for less than 2 seconds. (I have tried re-uploading and it's hit or miss every time I reupload) After researching this, an Arduino Form, several years back stated to add a delay to make up for the difference in the baud rates. I have tried multiple baud rates from 1-12, each is a hit and miss always cutting off before 10 seconds, with no consistency.
here's the code
/*
Electronic Level
mpu-6050-level.ino
Uses MPU-6050 IMU
Displays on 128x64 OLED and LED
DroneBot Workshop 2019
https://dronebotworkshop.com
*/
// Include Wire Library for I2C
#include <Wire.h>
// Define I2C Address - change if reqiuired
const int i2c_addr = 0x3F;
//Variables for Gyroscope
int gyro_x, gyro_y, gyro_z;
long gyro_x_cal, gyro_y_cal, gyro_z_cal;
boolean set_gyro_angles;
long acc_x, acc_y, acc_z, acc_total_vector;
float angle_roll_acc, angle_pitch_acc;
float angle_pitch, angle_roll;
int angle_pitch_buffer, angle_roll_buffer;
float angle_pitch_output, angle_roll_output;
// Setup timers and temp variables
long loop_timer;
int temp;
// Display counter
int displaycount = 0;
void setup() {
//Start I2C
Wire.begin();
//Setup the registers of the MPU-6050
setup_mpu_6050_registers();
//Read the raw acc and gyro data from the MPU-6050 1000 times
for (int cal_int = 0; cal_int < 1000 ; cal_int ++){
read_mpu_6050_data();
//Add the gyro x offset to the gyro_x_cal variable
gyro_x_cal += gyro_x;
//Add the gyro y offset to the gyro_y_cal variable
gyro_y_cal += gyro_y;
//Add the gyro z offset to the gyro_z_cal variable
gyro_z_cal += gyro_z;
//Delay 3us to have 250Hz for-loop
delay(3);
}
// Divide all results by 1000 to get average offset
gyro_x_cal /= 1000;
gyro_y_cal /= 1000;
gyro_z_cal /= 1000;
// Start Serial Monitor
Serial.begin(115200);
// Init Timer
loop_timer = micros();
}
void loop(){
// Get data from MPU-6050
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)
//Calculate the traveled pitch angle and add this to the angle_pitch variable
angle_pitch += gyro_x * 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_roll += gyro_y * 0.0000611;
//If the IMU has yawed transfer the roll angle to the pitch angle
angle_pitch += angle_roll * sin(gyro_z * 0.000001066);
//If the IMU has yawed transfer the pitch angle to the roll angle
angle_roll -= angle_pitch * sin(gyro_z * 0.000001066);
//Accelerometer angle calculations
//Calculate the total accelerometer vector
acc_total_vector = sqrt((acc_x*acc_x)+(acc_y*acc_y)+(acc_z*acc_z));
//57.296 = 1 / (3.142 / 180) The Arduino asin function is in radians
//Calculate the pitch angle
angle_pitch_acc = asin((float)acc_y/acc_total_vector)* 57.296;
//Calculate the roll angle
angle_roll_acc = asin((float)acc_x/acc_total_vector)* -57.296;
//Accelerometer calibration value for pitch
angle_pitch_acc -= 0.0;
//Accelerometer calibration value for roll
angle_roll_acc -= 0.0;
if(set_gyro_angles){
//If the IMU has been running
//Correct the drift of the gyro pitch angle with the accelerometer pitch angle
angle_pitch = angle_pitch * 0.9996 + angle_pitch_acc * 0.0004;
//Correct the drift of the gyro roll angle with the accelerometer roll angle
angle_roll = angle_roll * 0.9996 + angle_roll_acc * 0.0004;
}
else{
//IMU has just started
//Set the gyro pitch angle equal to the accelerometer pitch angle
angle_pitch = angle_pitch_acc;
//Set the gyro roll angle equal to the accelerometer roll angle
angle_roll = angle_roll_acc;
//Set the IMU started flag
set_gyro_angles = true;
}
//To dampen the pitch and roll angles a complementary filter is used
//Take 90% of the output pitch value and add 10% of the raw pitch value
angle_pitch_output = angle_pitch_output * 0.9 + angle_pitch * 0.1;
//Take 90% of the output roll value and add 10% of the raw roll value
angle_roll_output = angle_roll_output * 0.9 + angle_roll * 0.1;
//Wait until the loop_timer reaches 4000us (250Hz) before starting the next loop
// Print to Serial Monitor
Serial.print(" | Pitch = ");
Serial.println(angle_pitch_output);
Serial.print(" | Roll = ");
Serial.println(angle_roll_output);
delay(5);
// if (displaycount > 100) {
// Print on first row of LCD
// lcd.setCursor(0,0);
//lcd.print("Pitch: ");
// lcd.print(angle_pitch_output);
// lcd.setCursor(0,1);
// lcd.print("Roll: ");
// lcd.print(angle_roll_output);}
while(micros() - loop_timer < 4000);
//Reset the loop timer
loop_timer = micros();
}
void setup_mpu_6050_registers(){
//Activate the MPU-6050
//Start communicating with the MPU-6050
Wire.beginTransmission(0x68);
//Send the requested starting register
Wire.write(0x6B);
//Set the requested starting register
Wire.write(0x00);
//End the transmission
Wire.endTransmission();
//Configure the accelerometer (+/-8g)
//Start communicating with the MPU-6050
Wire.beginTransmission(0x68);
//Send the requested starting register
Wire.write(0x1C);
//Set the requested starting register
Wire.write(0x10);
//End the transmission
Wire.endTransmission();
//Configure the gyro (500dps full scale)
//Start communicating with the MPU-6050
Wire.beginTransmission(0x68);
//Send the requested starting register
Wire.write(0x1B);
//Set the requested starting register
Wire.write(0x08);
//End the transmission
Wire.endTransmission();
}
void read_mpu_6050_data(){
//Read the raw gyro and accelerometer data
//Start communicating with the MPU-6050
Wire.beginTransmission(0x68);
//Send the requested starting register
Wire.write(0x3B);
//End the transmission
Wire.endTransmission();
//Request 14 bytes from the MPU-6050
Wire.requestFrom(0x68,14);
//Wait until all the bytes are received
while(Wire.available() < 14);
//Following statements left shift 8 bits, then bitwise OR.
//Turns two 8-bit values into one 16-bit value
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();
}