Here's my code:

const int trigPin = 7;
const int echoPin = 6;

void setup() {
    Serial.begin(9600);
    pinMode(trigPin, OUTPUT);
    pinMode(echoPin, INPUT);
}

void loop() {
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);

    long duration = pulseIn(echoPin, HIGH);
    int distance = duration * 0.034 / 2;

    Serial.println(distance);
    delay(500);
}

The issues I am facing:

• The sensor sometimes returns very high or very low values randomly.
• The readings are unstable even when there’s a fixed object in front of it.
• Sometimes I even get 0 cm, even though there’s no obstacle that close.

Here's my basic setup:

• Arduino Uno
• SG90 servo motor powered from the Arduino's 5V pin
• Signal wire connected to pin 9

#include <Servo.h>

Servo myServo;

void setup() {
    myServo.attach(9);
    myServo.write(90); 
}

void loop() {
   
}

I've tried adding delay(1000); in the loop, but that didn't help. Do I need a separate power source for the servo, or is there another way to fix the jitter? Any advice would be greatly appreciated.

I've tried using digitalRead() in a simple if condition, but I suspect I need to debounce the button properly. Should I use delay(), or is there a better approach using millis()?

Here’s my basic code:

const int buttonPin = 2;
const int ledPin = 13;
bool ledState = false;

void setup() {
    pinMode(buttonPin, INPUT);
    pinMode(ledPin, OUTPUT);
}

void loop() {
    if (digitalRead(buttonPin) == HIGH) {
        ledState = !ledState;
        digitalWrite(ledPin, ledState);
        delay(200); // Debounce delay?
    }
}

Is there a more reliable way to debounce the button and avoid unwanted toggling? Any guidance would be appreciated!

I’m a bit confused about the delay() and millis() functions in Arduino. What’s the difference between them, and when should I use millis() instead of delay()?

I'm trying to understand why the analogWrite function in Arduino requires a value between 0 and 255 for PWM (Pulse Width Modulation). What does this range actually signify in terms of how PWM works? Why specifically these values, and how does it relate to controlling the output?

thank you 

From what I understand, the analogWrite() command is used to generate a PWM (Pulse Width Modulation) signal, which can be used to control devices like LEDs and motors. However, I noticed that this function is used on digital pins that support PWM, rather than the analog pins.

1. Why is the analogWrite() command used on PWM digital pins and not on analog pins even though the command name suggest it work for analog?

It would be great if someone could explain the technical reasons behind this.

I am using 8 digital pins to control the 8 LEDs separately. Instead of writing "pinMode(pin,OUTPUT)" for every other pin, is there any short method?

#define SENSOR_PIN A0
#define LED_PIN 13

void setup() {
  pinMode(SENSOR_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  int sensorValue = analogRead(SENSOR_PIN);
  if (sensorValue > 500) {
    digitalWrite(LED_PIN, HIGH);
  } else {
    digitalWrite(LED_PIN, LOW);
  }
}

Could someone explain to me what it does here and why to use it? Why not use this instead:

int SENSOR_PIN A0
int LED_PIN 13