Can anyone explain why this line of code is needed?

General Discussion
1

I’m a complete beginner, and thought I was doing OK, working through the starter projects until I came across this code for the starter project for operating a motor (it’s called the “4.1_motor_pwm” project).
The lines that I don’t get are the Serial.println(dutyCycle); lines. Why are those lines needed? I thought the ledcWrite line would have been all that was needed.
Any help gratefully received! But I need it in simple terms :grin:
Here’s the code:

#define motor1A 13
#define motor2A 14

// PWM settings
const int freq = 500; // PWM frequency: 500 Hz
const int resolution = 8; // PWM resolution: 8 bits

void setup() {
// Set up PWM
ledcAttach(motor1A, freq, resolution);
ledcAttach(motor2A, freq, resolution);

Serial.begin(115200);
}

void loop() {
// Increase speed gradually
for (int dutyCycle = 0; dutyCycle <= 255; dutyCycle++) {
Serial.println(dutyCycle);
ledcWrite(motor1A, dutyCycle);
ledcWrite(motor2A, 0);
delay(50);
}

delay(2000);

// Decrease speed gradually
for (int dutyCycle = 255; dutyCycle >= 0; dutyCycle–) {
Serial.println(dutyCycle);
ledcWrite(motor1A, dutyCycle);
ledcWrite(motor2A, 0);
delay(50);
}

delay(2000);
}

2

Functionally, you are correct, that’s all that’s needed. The println simply let you visualise what the programmed duty cycle is at that moment via the serial port as the loop executes

https://docs.arduino.cc/language-reference/en/functions/communication/serial/println/