Arduino Electronics Basics

Arduino Platform

• Arduino is an open-source electronics platform.
• It uses easy-to-use hardware and software.
• It has a microcontroller that can interact with other components.
• Creates interactive electronic projects using sensors, motors, lights, etc.

LEDs (Light Emitting Diodes)

• LEDs emit light when current flows through them.
• Commonly used as indicators, displays, lighting in projects.
• Used in Arduino projects for simple indicators and displaying information (e.g., blinking).

Diodes

• Diodes let current flow in one direction, but block it in the opposite.
• Protect circuits, prevent current backflow.
• Often used in Arduino in circuits for protection (reverse polarity).

Resistors

• Resistors limit or control current flow in a circuit.
• Measured in ohms (Ω).
• Limit current in circuits, preventing damage to components like LEDs and sensors.

Transistors

• Transistors are semiconductors that amplify or switch signals/power.
• Used in Arduino circuits to control larger currents (e.g., motors, relays).

Servo Motors

• Servo motors are precise motors for rotating or positioning parts.
• Controlled by sending PWM signals to achieve controlled angular movement.
• Arduino controls servo motors using PWM signals for precise rotation.

DC Motors

• DC motors use direct current electricity for rotating shafts/wheels.
• Controlled using transistors or motor drivers in Arduino circuits, adjusting speed and direction.

Piezo Buzzers

• Piezo buzzers produce sound using piezoelectric material.
• Used in Arduino for making sounds, alerts, or beeps.

Integrated Circuits (ICs)

• Integrated circuits are electronic circuits on a single chip.
• Can include logic gates, amplifiers, memory.
• Arduino boards are ICs; external ICs are used for additional tasks like communication, memory, or signal processing.

Pushbuttons

• Simple switches that complete/break circuits when pressed/released.
• Used to trigger events in Arduino projects, like on/off LEDs, changing program states.

Potentiometers

• Variable resistors with three terminals.
• Adjusting the knob changes resistance, producing a variable voltage output.
• Used to adjust values like brightness, speed, or position in Arduino projects.

Photoresistors (LDRs)

• LDRs change resistance based on light intensity.
• High resistance in dark, low resistance in light.
• Used in Arduino projects to detect light levels and trigger responses based on changes in light (e.g., automatically turning lights on at night).

setup() Function

• Executed once when the Arduino powers on or resets.
• Initialises pin modes, sets up serial communication.

loop() Function

• Runs continuously after setup().
• Contains the program's main logic and repeats until power off or reset.

Arduino Syntax

• Uses C/C++ syntax.
• Statements end with a semicolon (;).
• Code blocks use curly braces ({ }).

Variables

• Store data that changes during program execution.
• Have a data type (e.g., int, float, char) and a name.

Math Operations

• Used for arithmetic calculations (+, -, *, /, %).

Comparison Operators

• Compare two values (==, !=, <, >, <=, >=).

Control Structures

• Control program flow.
• if, else, else if statements check conditions.

Digital Signals

• Digital signals have two states (HIGH/LOW, representing 1/0).
• Arduino pins use digitalRead() and digitalWrite() for digital signals.

Analog Signals

• Continuous signals with any value within a range.
• Arduino analog input pins (e.g., A0) read values from sensors (analog voltages).
• analogRead() reads analog values; analogWrite() for PWM output.