Lab: Arduino Hardware

This lab introduces fundamental Arduino hardware components and sensors commonly used in IoT applications. Students will learn to interface with various sensors and actuators while understanding basic electronic principles.

1.1 Basic Components Overview

• Arduino UNO Board: The main microcontroller board featuring an ATmega328P processor, digital/analog I/O pins, and USB connectivity for programming.
• Breadboard: A solderless prototyping board for creating temporary circuits and testing connections.
• Jumper Wires: Male-to-male, female-to-female, and male-to-female wires for making electrical connections.
• Resistors: Various resistors (220Ω, 10kΩ) for current limiting and pull-up/pull-down configurations.

1.2 Sensors and Actuators

1.3 Lab Experiments

Experiment 1: LED Control

Basic digital output control using LEDs with different patterns:

• Single LED blinking
• Multiple LED sequences
• LED brightness control using PWM

Experiment 2: Temperature Monitoring

Using the DHT11 sensor to measure environmental conditions:

• Temperature and humidity readings
• Data display on LCD screen
• Temperature-triggered alerts using buzzer

Experiment 3: Interactive Light System

Combining multiple components:

• Light level detection using photoresistor
• Automatic LED control based on ambient light
• User override using push buttons

1.4 Hardware Setup & Connections

Circuit Diagrams and Connections

LED Control Setup

LED Circuit Connection Diagram

LED Blink Code Copy Code

// LED Blink Example
const int ledPin = 13;

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

void loop() {
    digitalWrite(ledPin, HIGH);
    delay(1000);
    digitalWrite(ledPin, LOW);
    delay(1000);
}
                                                    

Temperature Sensor Setup

DHT11 Circuit Connection Diagram

DHT11 Code Copy Code

#include "DHT.h"
#define DHTPIN 2
#define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);

void setup() {
    Serial.begin(9600);
    dht.begin();
}

void loop() {
    float h = dht.readHumidity();
    float t = dht.readTemperature();
    
    Serial.print("Humidity: ");
    Serial.print(h);
    Serial.print(" %\t");
    Serial.print("Temperature: ");
    Serial.print(t);
    Serial.println(" *C");
    
    delay(2000);
}
                                                    

Interactive Light System Setup

LDR Circuit Connection Diagram

Light System Code Copy Code

const int ldrPin = A0;
const int ledPin = 13;
const int buttonPin = 2;

int threshold = 500;
bool manualMode = false;

void setup() {
    pinMode(ledPin, OUTPUT);
    pinMode(buttonPin, INPUT_PULLUP);
    Serial.begin(9600);
}

void loop() {
    if (digitalRead(buttonPin) == LOW) {
        manualMode = !manualMode;
        delay(200);
    }

    if (!manualMode) {
        int lightLevel = analogRead(ldrPin);
        digitalWrite(ledPin, lightLevel < threshold);
    }
}
                                                    

LCD Display Setup

LCD Display Connection Diagram

LCD Display Code Copy Code

#include 

// Initialize LCD (pins: RS=12, E=11, D4=5, D5=4, D6=3, D7=2)
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
    // Set up the LCD's number of columns and rows
    lcd.begin(16, 2);
    
    // Print a message to the LCD
    lcd.print("Hello, World!");
}

void loop() {
    // Set the cursor to column 0, line 1
    // (note: line 1 is the second row, since counting begins with 0)
    lcd.setCursor(0, 1);
    
    // Print the number of seconds since reset
    lcd.print(millis() / 1000);
    
    delay(1000);
}
                                                    

Note: Make sure to install the LiquidCrystal library in your Arduino IDE before running this code. The LCD display requires proper voltage (5V) and contrast adjustment through the potentiometer for optimal visibility.