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Arduino Basics and Projects

Jul 13, 2025

Overview

This lecture provides a beginner-friendly introduction to Arduino, covering its hardware and software, programming basics, input/output handling, variables, functions, and building simple interactive LED projects.

Introduction to Arduino

  • Arduino is an open-source hardware and software platform for building electronic projects.
  • The Arduino board is a circuit board with a microcontroller (mainly Atmega328p) as its core.
  • Arduino IDE is the official free software for writing, compiling, and uploading code to Arduino boards.

Arduino Board and Pins

  • Microcontroller acts as the brain, running code and controlling hardware via pins.
  • Pins are grouped into digital pins, analog input pins, and power pins.
  • Digital pins (13 on Uno) act as on/off switches (0V for off, 5V for on).
  • Analog pins read varying voltage values (0-5V), useful for sensors.
  • PWM pins (marked with ~) simulate analog output using digital signals.

Powering Arduino

  • Arduino can be powered via USB or an external power supply (recommended 12V via DC Barrel Jack).

Setting up Arduino IDE

  • Download and install Arduino IDE 1.8.
  • Adjust preferences for readability (font size, line numbers).
  • Select appropriate board and COM port before uploading code.

Basic Arduino Programming Structure

  • An Arduino program (sketch) uses C/C++ and consists of setup() and loop() functions.
  • setup() runs once; loop() runs repeatedly.
  • Functions must be correctly named (case-sensitive) and use curly brackets for their body.
  • Comments (// for single-line, /* */ for multi-line) help document code.

Controlling LEDs and Using Functions

  • pinMode() configures pins as INPUT or OUTPUT.
  • digitalWrite(pin, HIGH/LOW) sends digital signals to pins.
  • delay(ms) pauses program execution.
  • Use functions to organize repetitive code, making programs clearer and easier to manage.

Serial Communication and Monitoring

  • Serial Monitor allows real-time data viewing and interaction between Arduino and computer.
  • serial.begin(9600) starts communication; serial.println() sends data to the monitor.

Variables and Data Types

  • Variables are containers for data, defined by data type and name (e.g., int, float, boolean).
  • Constants (const keyword) store unchangeable values, like pin numbers.
  • Variable scope determines where a variable can be accessed (local or global).
  • Main data types: boolean (true/false), byte (0-255), int (whole numbers), long (large numbers), float/double (decimals), char (single characters).
  • Use the correct data type to avoid errors like garbage values.

Operators in Arduino

  • Arithmetic operators: +, -, *, /, % for basic calculations.
  • Increment (++) and decrement (--) operators adjust variable values.
  • Relational operators (>, <, >=, <=, ==, !=) compare values and return true/false.*

Control Structures: Loops and If Statements

  • for loops repeat code a specific number of times with initialization, condition, and increment.
  • if and if-else statements make decisions based on conditions.

Working with Digital and Analog Inputs/Outputs

  • digitalRead(pin) reads if a pin is HIGH or LOW (e.g., button presses).
  • analogRead(pin) reads analog values (0-1023) from sensors.
  • analogWrite(pin, value) uses PWM to control outputs like LED brightness (value 0-255).
  • Use map() to scale analog readings to PWM range.

Sample Projects

  • Blink an LED using digitalWrite and delay.
  • Create LED patterns and chasers using functions and loops.
  • Use PWM and potentiometer to control LED brightness smoothly.
  • Read button states and control LEDs using if statements.
  • Use the Serial Monitor to display sensor values and debug.

Key Terms & Definitions

  • Microcontroller — A small computer on a single chip that runs Arduino code.
  • IDE (Integrated Development Environment) — Software to write and upload code to Arduino.
  • Digital Pin — Pin handling on/off (0/5V) signals.
  • Analog Pin — Pin reading continuous voltage values (0-5V).
  • PWM (Pulse Width Modulation) — Technique for simulating analog output using digital pins.
  • Serial Monitor — Tool for exchanging data between Arduino and computer.
  • Variable — Named storage for data.
  • Constant — Read-only variable whose value cannot change.
  • Scope — Part of code where a variable is accessible.
  • Function — A reusable block of code with a specific task.
  • For Loop — Control structure for repeating code a set number of times.
  • If Statement — Control structure for decision making.

Action Items / Next Steps

  • Download and install Arduino IDE 1.8.
  • Set up your Arduino board and connect via USB.
  • Complete example projects: LED blink, LED chaser, potentiometer-controlled LED.
  • Explore Serial Monitor and variables in code.
  • Practice writing and modifying basic sketches using loops, conditionals, and functions.

Full transcript