// Servo Sweep example for STM32 Nucleo-C031C6
// Using Manual PWM control
#define dcservoPin D9
//const int dcservoPin = 9;  // Pin D9 on STM32 Nucleo
// can be #define servoPIN D9
// It gives you the benefit of type safety.
// Since it's defined as an integer,
// the compiler knows to expect an integer value and will give you an error
// if you try to assign a non-integer value to it.
// You can also use it in expressions or calculations if needed.

const int minPulseWidth = 500;  // Minimum pulse width (in microseconds)
const int maxPulseWidth = 2400; // Maximum pulse width (in microseconds)

// 500 µs to 2400 µs is the standard pulse width range
//used by most standard hobby servos to control the position of the motor.

//=====================================================================
void setup() {
  pinMode(dcservoPin, OUTPUT);  // Set the dcservoPin as an output
}

void loop() {
  // Move to 0 degrees
  servoAngle(0);
  delay(1000);
  
  // Move to 45 degrees
  servoAngle(45);
  delay(1000);
  
  // Move to 90 degrees
  servoAngle(90);
  delay(1000);
  
  // Move to 135 degrees
  servoAngle(135);
  delay(1000);
  
  // Move to 180 degrees
  servoAngle(180);
  delay(1000);
  
  // Move back to 0 degrees
  servoAngle(0);
  delay(500);
}

// Function to generate a PWM pulse for the servo motor
void servoAngle(int angle) {
  // Calculate the pulse width for the given angle
  int pulseWidth = map(angle, 0, 180, minPulseWidth, maxPulseWidth);
  //map() is a built-in function in Arduino environment.
  //It maps a number from one range to another.


  // Generate the PWM signal (1 ms to 2.4 ms pulse width)
  digitalWrite(dcservoPin, HIGH);
  delayMicroseconds(pulseWidth);
  digitalWrite(dcservoPin, LOW);
  delay(20 - pulseWidth / 1000);  // Rest of the 20ms period
}
// NOTE:
//The pulse width (500 to 2400 microseconds)
//is a small portion of the 20ms total period.

// IN SHORT:
// The 500 and 2400 microseconds
// are the time the signal stays HIGH,
// controlling the servo's position.
// 20ms is the total time for one cycle,
// where the HIGH time is the active portion
// and the LOW time is the idle portion.