SLIOT 2026 Workshop Materials

Installation Guide

Download this batchfile and run as administrator

Pinout Guide

Pin Reference

Safe Pins

Images are adopted from this article : https://lastminuteengineers.com/esp32-pinout-reference

Demonstration Guides

Blink

int LED_BUILTIN = 2;
void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_BUILTIN, HIGH);  // turn the LED on (HIGH is the voltage level)
  delay(1000);                      // wait for a second
  digitalWrite(LED_BUILTIN, LOW);   // turn the LED off by making the voltage LOW
  delay(1000);                      // wait for a second
}

LED Fade

int LED_PIN = 4;
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_PIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
for (int brightness = 0; brightness <= 255; brightness++) {
    analogWrite(LED_PIN, brightness);
    delay(10); // Adjust the speed of fading
  }

  // Decrease brightness
  for (int brightness = 255; brightness >= 0; brightness--) {
    analogWrite(LED_PIN, brightness);
    delay(10);
  }
}

Buzzer

#define BUZZER_PIN 4 // sama as int Buzzer_pin = 4
int frequency = 200; //200hz

void setup() {
  pinMode(BUZZER_PIN,OUTPUT);
}

void loop() {
  tone(BUZZER_PIN,frequency,1000);
  noTone(BUZZER_PIN);
  delay(1000);
 }

Servo Motor

/* ESP32 Servo Sweep */
#include <ESP32Servo.h>

const int servoPin = 4; /* GPIO14 */

Servo servo1;

void setup()
{ 
 Serial.begin(115200);
 servo1.attach(servoPin);

}
void loop()
{
  for(int posDegrees = 0; posDegrees <= 180; posDegrees++) {
    servo1.write(posDegrees);
    Serial.println(posDegrees);
    delay(20);
  }

  for(int posDegrees = 180; posDegrees >= 0; posDegrees--) {
    servo1.write(posDegrees);
    Serial.println(posDegrees);
    delay(20);
  }
}

Push Button - Active HIGH

Push Button - Active LOW

LDR-Analog Input

int pin = 4;
void setup() {
  pinMode(pin,INPUT);
  Serial.begin(115200);
}

void loop() {
  int ldr_reading = analogRead(pin);
  Serial.println(ldr_reading);
  delay(1000);
}

DHT11

#include "DHT.h"
#define DHTPIN 4 // Digital pin connected to the DHT sensor
#define DHTTYPE DHT11 // DHT 11 (AM2302), AM2321
DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(115200);
  Serial.println("DHTxx test!");
  dht.begin();
}

void loop() {
  delay(2000);

  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();
  // Read temperature as Fahrenheit (isFahrenheit = true)
  float f = dht.readTemperature(true);

  // Check if any reads failed and exit early (to try again).
  if (isnan(h) || isnan(t) || isnan(f)) {
    Serial.println(F("Failed to read from DHT sensor!"));
    return;
  }

  Serial.print(F("Humidity: "));
  Serial.print(h);
  Serial.print(F("% Temperature: "));
  Serial.print(t);
  Serial.print(F("°C "));
  Serial.println(f);
}

All together - Simple project

int ldrPin = 4;
int buzzerPin = 5;

// Threshold for detecting a shadow (you may need to adjust this)
// ESP32 analog reads go from 0 to 4095
int threshold = 1500; 

void setup() {
  pinMode(ldrPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  Serial.begin(115200);
}

void loop() {
  int ldr_reading = analogRead(ldrPin);
  Serial.print("LDR Reading: ");
  Serial.println(ldr_reading);
  
  // If the reading drops below the threshold, a shadow is detected
  if (ldr_reading < threshold) {
    digitalWrite(buzzerPin, HIGH); // Turn the buzzer ON
  } else {
    digitalWrite(buzzerPin, LOW);  // Turn the buzzer OFF
  }

  delay(500); // Reduced delay for better responsiveness
}

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Servo Motors

Servo motor pinout

Installing EspServo library