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Arduino Programming

Getting Started

Gather Necessary Materials

  • Arduino Board: Any model, such as Arduino Uno, Mega, Nano, etc.
  • USB Cable: Compatible with your Arduino board (commonly USB Type-A to Type-B for Uno).
  • Computer: Windows, macOS, or Linux.

Install the Arduino IDE

  • windows/mac/linux
  • Go to the Arduino Software page.
  • Download the os installer.
  • Run the installer and follow the instructions.

Connect Your Arduino Board

  • Connect the Arduino board to your computer using the USB cable.
  • The power LED on the Arduino should light up, indicating it’s receiving power.

Configure the Arduino IDE

  • Open the Arduino IDE.

  • Select Your Board:

  • Go to Tools > Board and select the model of your Arduino board (e.g., Arduino Uno).

  • Select the Port:

  • Go to Tools > Port and select the port that the Arduino is connected to (it usually shows as COMx on Windows, /dev/cu.usbmodemxxxx on macOS, and /dev/ttyUSBx on Linux).

Basic Structure

Setup and Loop

void setup() {
  // Code here runs once
}


void loop() {
  // Code here runs repeatedly
}

Comment

// Single-line comment


/*
Multi-line
comment
*/

Variable

int ledPin = 13; // Integer
float voltage = 5.0; // Floating-point number
char letter = 'A'; // Character
String text = "Hello"; // String

Pin Modes

pinMode(pin, mode);

Digital I/O

digitalWrite(pin, value);
int value = digitalRead(pin);

Analog I/O

analogWrite(pin, value);
int value = analogRead(pin);

Serial Communication

Begin Serial Communication

Serial.begin(baudRate);
Serial.print(data);
Serial.println(data);

Read from Serial Monitor

if (Serial.available()) {
  char data = Serial.read();
}

Control Structures

If Statement

if (condition) {
  // Code to execute if condition is true
} else {
  // Code to execute if condition is false
}

For Loop

for (initialization; condition; increment) {
  // Code to execute
}

While Loop

while (condition) {
  // Code to execute
}

Functions

returnType functionName(parameters) {
  // Code to execute
  return value;
}

Libraries

Include a Library

#include <LibraryName.h>

Using a Library

#include <Servo.h>


Servo myServo;


void setup() {
  myServo.attach(9); // Attach servo to pin 9
}


void loop() {
  myServo.write(90); // Set servo to 90 degrees
  delay(1000);
  myServo.write(0); // Set servo to 0 degrees
  delay(1000);
}

Common Functions

Delay

delay(milliseconds);

Millis

unsigned long currentTime = millis();

Map

long outputValue = map(inputValue, fromLow, fromHigh, toLow, toHigh);

Random

long randomValue = random(max);
long randomValue = random(min, max);

Random Seed

randomSeed(analogRead(0)); // Seed from analog pin 0

Sensors and Modules

Reading Temperature with DHT Sensor

#include <DHT.h>


#define DHTPIN 2     // Pin which is connected to the DHT sensor
#define DHTTYPE DHT11   // DHT 11


DHT dht(DHTPIN, DHTTYPE);


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


void loop() {
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();


  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" *C");


  delay(2000);
}

Blinking LED

const int ledPin = 13;


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


void loop() {
  digitalWrite(ledPin, HIGH);  // Turn the LED on
  delay(1000);                 // Wait for 1 second
  digitalWrite(ledPin, LOW);   // Turn the LED off
  delay(1000);                 // Wait for 1 second
}

Read Button Input

const int buttonPin = 2;  // Pin where the push button is connected
const int ledPin = 13;    // Pin where the LED is connected


void setup() {
  pinMode(buttonPin, INPUT);  // Set the button pin as an input
  pinMode(ledPin, OUTPUT);    // Set the LED pin as an output
}


void loop() {
  int buttonState = digitalRead(buttonPin);  // Read the state of the button


  if (buttonState == HIGH) {
    digitalWrite(ledPin, HIGH);  // Turn the LED on
  } else {
    digitalWrite(ledPin, LOW);   // Turn the LED off
  }
}

Analog Input

const int potPin = A0;    // Pin where the potentiometer is connected
const int ledPin = 9;     // Pin where the LED is connected


void setup() {
  pinMode(ledPin, OUTPUT);  // Set the LED pin as an output
}


void loop() {
  int potValue = analogRead(potPin);  // Read the potentiometer value
  int ledBrightness = map(potValue, 0, 1023, 0, 255);  // Map the value to a range from 0 to 255


  analogWrite(ledPin, ledBrightness);  // Set the brightness of the LED
  delay(10);  // Small delay to make the LED change smoothly
}

Serial Communication

void setup() {
  Serial.begin(9600);  // Start the serial communication at 9600 baud rate
}


void loop() {
  Serial.println("Hello, world!");  // Send a message to the serial monitor
  delay(1000);  // Wait for 1 second
}

Temperature Sensor

const int tempPin = A0;  // Pin where the TMP36 sensor is connected


void setup() {
  Serial.begin(9600);  // Start the serial communication at 9600 baud rate
}


void loop() {
  int tempValue = analogRead(tempPin);  // Read the sensor value
  float voltage = tempValue * (5.0 / 1023.0);  // Convert the value to voltage
  float temperatureC = (voltage - 0.5) * 100;  // Convert the voltage to temperature in Celsius


  Serial.print("Temperature: ");
  Serial.print(temperatureC);
  Serial.println(" C");
  delay(1000);  // Wait for 1 second
}

RGB LED Control

const int redPin = 9;
const int greenPin = 10;
const int bluePin = 11;


const int potRedPin = A0;
const int potGreenPin = A1;
const int potBluePin = A2;


void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
}


void loop() {
  int redValue = analogRead(potRedPin);
  int greenValue = analogRead(potGreenPin);
  int blueValue = analogRead(potBluePin);


  analogWrite(redPin, map(redValue, 0, 1023, 0, 255));
  analogWrite(greenPin, map(greenValue, 0, 1023, 0, 255));
  analogWrite(bluePin, map(blueValue, 0, 1023, 0, 255));


  delay(10);
}

Ultrasonic Sensor

const int trigPin = 9;
const int echoPin = 10;


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


void loop() {
  long duration;
  int distance;


  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);


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


  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  delay(1000);
}

Controlling a Servo Motor

#include <Servo.h>


Servo myServo;
const int potPin = A0;


void setup() {
  myServo.attach(9);  // Attach the servo to pin 9
}


void loop() {
  int potValue = analogRead(potPin);  // Read the potentiometer value
  int angle = map(potValue, 0, 1023, 0, 180);  // Map the value to an angle between 0 and 180


  myServo.write(angle);  // Set the servo position
  delay(15);  // Small delay for the servo to reach the position
}

Displaying Text on an LCD

#include <LiquidCrystal.h>


// Initialize the library with the numbers of the interface pins
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 (second row)
  lcd.setCursor(0, 1);
  // Print the number of seconds since reset
  lcd.print(millis() / 1000);
}

Wireless Communication with NRF24L01

Transmitter Code

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>


RF24 radio(9, 10);  // CE, CSN pins


const byte address[6] = "00001";  // Address


void setup() {
  radio.begin();
  radio.openWritingPipe(address);
  radio.setPALevel(RF24_PA_MIN);
  radio.stopListening();
}


void loop() {
  const char text[] = "Hello";
  radio.write(&text, sizeof(text));
  delay(1000);
}

Receiver Code

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>


RF24 radio(9, 10);  // CE, CSN pins


const byte address[6] = "00001";  // Address


void setup() {
  Serial.begin(9600);
  radio.begin();
  radio.openReadingPipe(0, address);
  radio.setPALevel(RF24_PA_MIN);
  radio.startListening();
}


void loop() {
  if (radio.available()) {
    char text[32] = "";
    radio.read(&text, sizeof(text));
    Serial.println(text);
  }
}

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