Arduino Switches & Displays

Light Emitting Diode

What does LED stands for?

Liquid Crystal Display

What does LCD stands for?

Light Emitting Diode

What des OLED stands for?

Light Emitting Diode

Emit one color if an input voltage greater than the threshold voltage of its PN junction.

RGB

A solution to provide multiple colors with a single LED. In this LED we have 4 pins.

8 - bit Binary Code

Every color value is stored in digital representation as an

VSS stands for?

Stands for the ground pin

VDD Stands for?

Stands for the power supply

VEE Stands for?

The control pin to control the brightness

RS Stands for?

Register select pin let us decode between Command/Data Register

RW Stands for?

Read/Write pin helps in declining whether to read or write on the LCD.

Neopixels

A special type of RGB LEDs that are arranged on a strip. Multiple LEDs are connected in a straight or circular manner

Digital Input

A type of input that can only read two states: HIGH (1) or LOW (0).

Pull-Up Resistor

A resistor that keeps a pin at HIGH when the switch is open, preventing random/noisy readings

Pushbutton (Momentary Switch)

A switch that only stays ON while being pressed; returns to OFF when released.

Toggle Switch

A switch that stays in its ON or OFF position until manually changed.

Debouncing

The process of removing the noisy rapid ON/OFF signals caused when a physical button is pressed.

Analog Input

A pin that can read voltage values between 0–5V and convert them into a number (0–1023).

Potentiometer

A variable resistor used to adjust voltage, often used for contrast in LCDs or controlling brightness.

Photoresistor (LDR)

A light-dependent resistor whose resistance changes with light levels.

Interrupt

A hardware-triggered event that pauses the main code to immediately execute a separate function.

LED (Light Emitting Diode)

A small light source that turns ON when current flows through it.

RGB LED

A single LED that can produce different colors by combining Red, Green, and Blue channels.

Seven-Segment Display

A numeric display made of 7 LED segments used to show digits 0–9

Common Anode

A 7-segment display where all positive terminals (anodes) are connected together.

Common Cathode Display

LCD Contrast

The visibility of characters on the LCD, usually adjusted through a potentiometer.

2C Module

A communication interface that allows LCDs and sensors to use only two wires

NeoPixel (WS2812 LED)

An individually addressable RGB LED that can produce millions of colors through a single data pin.

HIGH

A digital pin state representing 5V (ON).

PWM (Pulse Width Modulation)

A technique where Arduino rapidly switches a pin ON/OFF to simulate analog output (for brightness control).

Resistor

An electronic component that limits current to protect LEDs, switches, and displays.

Breadboard

A tool used to build circuits without soldering.

Soldering

A process of permanently joining wires and components using melted metal.

Cathode

The negative terminal of an LED.

Anode

The positive terminal of an LED.

Current Limiting Resistor

A resistor placed in series with an LED to prevent it from burning out.

A wire used to connect components on a breadboard.

Current Limiting Resistor

Jumper Wire

A wire used to connect components on a breadboard.

Serial Monitor

A built-in Arduino tool used to display data from the board.

Pin Mode

A command (pinMode()) that sets a pin as INPUT, OUTPUT, or INPUT_PULLUP.

Analog Write

A function that outputs a PWM signal for dimming or speed control.

AnalogRead

A function that reads analog voltage values (0–1023).

Debounce Delay

A small delay added to remove switch noise (e.g., 20–50ms).

Common Ground

A shared negative connection that ensures stable circuit operation.

Data Pin

The pin used to send instructions to NeoPixels or LED strips.

Backlight

The LED light behind an LCD that makes characters visible.

Refresh Rate

The speed at which a display updates, affecting animations and responsiveness.

Latching Switch

A switch that stays permanently in ON or OFF until toggled again (unlike pushbuttons).