Arduino UNO R3 with the x-nucleo-iks01a3

[Giuseppe1]

Hi, i connected the Arduino UNO R3 with the motion MEMS and environmental sensor evaluation board system: X-NUCLEO-IKS01A3 of ST. I installed the library (STM32duino,LSM6DSO), and tried to create a code for a self-balancing robot. But it doesn't print the right angle.

// Includes
#include <LSM6DSOSensor.h>

#ifdef ARDUINO_SAM_DUE
#define DEV_I2C Wire1
#elif defined(ARDUINO_ARCH_STM32)
#define DEV_I2C Wire
#elif defined(ARDUINO_ARCH_AVR)
#define DEV_I2C Wire
#else
#define DEV_I2C Wire
#endif
#define SerialPort Serial

int16_t accY, accZ, gyroX;
volatile int motorPower, gyroRate;
volatile float accAngle, gyroAngle, currentAngle, prevAngle=0, error, prevError=0, errorSum=0;
volatile byte count=0;

unsigned long currTime, prevTime=0, loopTime;

#define leftMotorPWMPin   6
#define leftMotorDirPin   7
#define rightMotorPWMPin  5
#define rightMotorDirPin  4

#define Kp  40
#define Kd  0.05
#define Ki  40
#define sampleTime  0.005
#define targetAngle -2.5


// Components
LSM6DSOSensor AccGyr(&DEV_I2C);


void setMotors(int leftMotorSpeed, int rightMotorSpeed) {
  if(leftMotorSpeed >= 0) {
    analogWrite(leftMotorPWMPin, leftMotorSpeed);
    digitalWrite(leftMotorDirPin, LOW);
  }
  else {
    analogWrite(leftMotorPWMPin, 255 + leftMotorSpeed);
    digitalWrite(leftMotorDirPin, HIGH);
  }
  if(rightMotorSpeed >= 0) {
    analogWrite(rightMotorPWMPin, rightMotorSpeed);
    digitalWrite(rightMotorDirPin, LOW);
  }
  else {
    analogWrite(rightMotorPWMPin, 255 + rightMotorSpeed);
    digitalWrite(rightMotorDirPin, HIGH);
  }
}

void init_PID() {  
  // initialize Timer1
  cli();          // disable global interrupts
  TCCR1A = 0;     // set entire TCCR1A register to 0
  TCCR1B = 0;     // same for TCCR1B    
  // set compare match register to set sample time 5ms
  OCR1A = 9999;    
  // turn on CTC mode
  TCCR1B |= (1 << WGM12);
  // Set CS11 bit for prescaling by 8
  TCCR1B |= (1 << CS11);
  // enable timer compare interrupt
  TIMSK1 |= (1 << OCIE1A);
  sei();          // enable global interrupts
}

void setup() {

  // set the motor control and PWM pins to output mode
  pinMode(leftMotorPWMPin, OUTPUT);
  pinMode(leftMotorDirPin, OUTPUT);
  pinMode(rightMotorPWMPin, OUTPUT);
  pinMode(rightMotorDirPin, OUTPUT);

  // Led.
  pinMode(LED_BUILTIN, OUTPUT);

  // Initialize serial for output.
  SerialPort.begin(9600);
  
  // Initialize I2C bus.
  DEV_I2C.begin();
  
  AccGyr.begin();
  AccGyr.Enable_X();
  AccGyr.Enable_G();
  // initialize PID sampling loop
  init_PID();
}

void loop() {

  // Read accelerometer and gyroscope.
  int32_t accelerometer[3];
  int32_t gyroscope[3];
  AccGyr.Get_X_Axes(accelerometer);
  AccGyr.Get_G_Axes(gyroscope);

accZ = accelerometer[2];
  accY = accelerometer[1];

   // set motor power after constraining it
  motorPower = constrain(motorPower, -255, 255);
  setMotors(motorPower, motorPower);

gyroX = gyroscope[0];
}

  // The ISR will be called every 5 milliseconds
ISR(TIMER1_COMPA_vect)
{

  accAngle = atan2(accY, accZ)*RAD_TO_DEG;
  
  if(isnan(accAngle));
 else
    Serial.println(accAngle);
   

 currTime = millis();
  loopTime = currTime - prevTime;
  prevTime = currTime;

  gyroRate = map(gyroX, -32768, 32767, -250, 250);
  gyroAngle = gyroAngle + (float)gyroRate*loopTime/1000;
  currentAngle = 0.9934*(prevAngle + gyroAngle) + 0.0066*(accAngle);

  error = currentAngle - targetAngle;
  errorSum = errorSum + error;  
  errorSum = constrain(errorSum, -300, 300);
  //calculate output from P, I and D values
  motorPower = Kp*(error) + Ki*(errorSum)*sampleTime - Kd*(currentAngle-prevAngle)/sampleTime;
  prevAngle = currentAngle;

  // Output data.
  //Serial.println(gyroAngle);
  //Serial.println(accAngle);
  Serial.println(currentAngle);
 /* SerialPort.print("| Acc[mg]: ");
  SerialPort.print(accelerometer[0]);
  SerialPort.print(" ");
  SerialPort.print(accelerometer[1]);
  SerialPort.print(" ");
  SerialPort.print(accelerometer[2]);
  SerialPort.print(" | Gyr[mdps]: ");
  SerialPort.print(gyroscope[0]);
  SerialPort.print(" ");
  SerialPort.print(gyroscope[1]);
  SerialPort.print(" ");
  SerialPort.print(gyroscope[2]);
  SerialPort.println(" |");*/
}

[Andrew Neil]

---

@Giuseppe1 wrote:

the Arduino UNO R3

---

Is that an AVR-based (R3 or earlier) or ARM-based (R4) UNO ?

---

@Giuseppe1 wrote:

 I installed the library (STM32duino,LSM6DSO), 

---

STM32duino is an Arduino Core for running on STM32 chips - so not relevant here?

---

@Giuseppe1 wrote:

 tried to create a code for a self-balancing robot. But it doesn't print the right angle.

---

So before leaping into all the complexities of self-balancing robots, did you first get the basic printing and sensor reading working?

You need that foundation working first before you move on to the advanced stuff!

[Giuseppe1]

It is AVR-based. 
I tried to print the x,y,z values of the accelerometer and gyroscope, and it worked(code below)
Then i followed this tutorial: https://www.instructables.com/Arduino-Self-Balancing-Robot-1/ 
So i changed the lines where there is the MPU sensor. But it print (for current angle) always like -560(it never change the value).

// Includes
#include <LSM6DSOSensor.h>

#ifdef ARDUINO_SAM_DUE
#define DEV_I2C Wire1
#elif defined(ARDUINO_ARCH_STM32)
#define DEV_I2C Wire
#elif defined(ARDUINO_ARCH_AVR)
#define DEV_I2C Wire
#else
#define DEV_I2C Wire
#endif
#define SerialPort Serial

// Components
LSM6DSOSensor AccGyr(&DEV_I2C);

void setup() {
  // Led.
  pinMode(LED_BUILTIN, OUTPUT);

  // Initialize serial for output.
  SerialPort.begin(115200);
  
  // Initialize I2C bus.
  DEV_I2C.begin();
  
  AccGyr.begin();
  AccGyr.Enable_X();
  AccGyr.Enable_G();
}

void loop() {
  // Led blinking.
  digitalWrite(LED_BUILTIN, HIGH);
  delay(250);
  digitalWrite(LED_BUILTIN, LOW);
  delay(250);

  // Read accelerometer and gyroscope.
  int32_t accelerometer[3];
  int32_t gyroscope[3];
  AccGyr.Get_X_Axes(accelerometer);
  AccGyr.Get_G_Axes(gyroscope);

  // Output data.
  SerialPort.print("| Acc[mg]: ");
  SerialPort.print(accelerometer[0]);
  SerialPort.print(" ");
  SerialPort.print(accelerometer[1]);
  SerialPort.print(" ");
  SerialPort.print(accelerometer[2]);
  SerialPort.print(" | Gyr[mdps]: ");
  SerialPort.print(gyroscope[0]);
  SerialPort.print(" ");
  SerialPort.print(gyroscope[1]);
  SerialPort.print(" ");
  SerialPort.print(gyroscope[2]);
  SerialPort.println(" |");
}

[Andrew Neil]

So does that code that you just posted work or not?