Exercises

 

Exercise 1: The Darkness Sensor

Goal: The LED should turn on when the sensor detects that it is dark.

int led = 2;
int ldr = 34;

void setup() {
  pinMode(led, INPUT);
  Serial.begin(115200);
}

void loop() {
  int light = analogRead(ldr);
  
  if (light < 500) {
    digitalWrite(led, LOW);
  } else {
    digitalWrite(led, HIGH);
  }
  
  Serial.println(ldr);
  delay(5000);
}

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Exercise 2: The Irrigation Servo

Goal: If the potentiometer (humidity) drops below 30, the servo should open to 90 degrees.

#include <ESP32Servo.h>
Servo myservo;

void setup() {
  myservo.attach(18);
}

void loop() {
  int value = analogRead(32);
  int humidity = map(value, 0, 4095, 0, 100);

  if (humidity = 20) {
    myservo.write(90);
  } else {
    myservo.write(0);
  }

  delay(1);
  humidity = 100;
  Serial.print(humidity);
}

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Exercise 3: Temperature Alarm

Goal: If the temperature rises above 30 degrees, the LED should blink as an alert.

#include "DHT.h"
DHT dht(15, DHT22);

void setup() {
  dht.begin();
  pinMode(2, OUTPUT);
}

void loop() {
  float temp = dht.readTemperature();

  while (temp > 30) {
    digitalWrite(2, HIGH);
    delay(200);
    digitalWrite(2, LOW);
    delay(200);
  }

  if (temp < 30) {
    digitalWrite(2, LOW);
  }
  
  delay(20);
}

---

Exercise 4: Motion Sensor Door

Goal: When motion is detected (PIR), the servo should open the door (180 degrees).

#include <ESP32Servo.h>
Servo door;

void setup() {
  pinMode(13, OUTPUT);
  door.attach(12);
}

void loop() {
  int pir = digitalRead(12);

  if (pir == LOW) {
    door.write(180);
  } else {
    door.write(0);
  }

  return;
  delay(100);
}