Introduction to Light-Emitting Diodes (LEDs) and Analog Signals with Arduino

A set of vocabulary flashcards covering the components of LEDs, Arduino programming basics, and the differences between digital and analog signals.

Light-Emitting Diode (LED)

A semiconductor device that emits light when an electric current flows through it via a process known as electroluminescence.

Electroluminescence

The process where electric current flows through an LED, electrons recombine with electron holes, and energy is released as photons.

Photons

Light particles released during the recombination of electrons and electron holes within an LED's semiconductor material.

Epoxy lens/case

The outer covering that protects the LED's internal components and often helps focus the light.

Wire bond

Tiny wires that connect the LED chip to two leads known as the anode and cathode.

Reflective cavity

The internal part of an LED that reflects light outward to increase the device's brightness.

Semiconductor die

Referred to as the heart of the LED, this component emits light when electricity is applied.

Anvil leadframe and post

Mechanical structures that provide support to the semiconductor die and wire bond while providing electrical connections.

Flat spot

A physical indicator on the LED body that denotes the cathode side.

Anode (+)

The positive electrical lead of an LED.

Cathode (-)

The negative electrical lead of an LED.

Arduino

A microcontroller device described as a puppet master for electronics that allows users to control components like LEDs through coding.

Digital Signal

A type of signal in Arduino that has only two states: HIGH ($1$) or LOW ($0$).

Analog Signal

Continuous voltage values ranging from $0$ to $5$ volts that can change smoothly and represent any value within a certain range.

Pulse Width Modulation (PWM)

A technique used by microcontrollers to simulate analog output by rapidly switching a digital pin on and off.

Analog-to-Digital Converter (ADC)

A tool used by Arduino to convert a voltage (typically from $0V$ to $5V$) into a digital value ranging from $0$ to $1023$.

Potentiometer

A variable resistor used to adjust analog signals smoothly, such as controlling volume, light brightness, or motor position.

Variable

A container used to store data like numbers, characters, or sensor readings in code (Syntax: $\text{datatype variableName = value;}$).

pinMode()

A function used to set a specific pin’s mode as either an input or an output.

digitalRead()

A function used to read the state ($HIGH$ or $LOW$) of a digital input pin.

analogRead()

A function that reads the analog voltage on input pins and converts it into a digital value between $0$ and $1023$.

digitalWrite()

A function used to set a digital pin to $HIGH$ (ON) or $LOW$ (OFF).

analogWrite()

A function used to output a PWM signal to simulate an analog voltage.

delay()

A function that tells the Arduino to wait for a specified amount of time, measured in milliseconds, before executing the next line of code.

Serial.begin(9600)

A command that starts serial communication at a baud rate of $9600$ bits per second.

setup()

An Arduino code function that contains initialization settings and runs only once when the board starts.

loop()

An Arduino code function that contains the main code which runs repeatedly.