Glossary of Key Terms
Glossary of Key Terms
| Term | Definition |
| analogRead() | A function that reads the voltage applied to one of the analog input pins and returns a number between 0 and 1023. |
| analogWrite() | A function that writes an analog value (as a PWM wave) to a pin. Used to vary LED brightness or motor speed. |
| AREF | Analog Reference. A pin used to set an external reference voltage (between 0 and 5 Volts) as the upper limit for the analog input pins. |
| Array | A consecutive group of memory locations that are of the same type. |
| attachInterrupt() | The function used to set up a hardware interrupt, specifying the pin, the ISR to call, and the mode (e.g., LOW, CHANGE, FALLING). |
| Barrel Jack | A power connection on the Arduino board used for connecting an AC mains power supply. |
| Baud Rate | The number of bits transferred per second (bps) in serial communication. |
| Boolean | A data type that holds one of two values, true or false, and occupies one byte of memory. |
| Crystal Oscillator | A component on the Arduino board that helps it deal with time issues. On the UNO, it has a frequency of 16 MHz. |
| DC Motor | A common type of motor with two leads (positive and negative) that rotates when connected to a direct current source. |
| delay() | A function that pauses the program for a specified amount of time in milliseconds. |
| digitalWrite() | A function used to write a HIGH or a LOW value to a digital pin. |
| Duty Cycle (PWM) | The percentage of time a PWM signal remains on (high) during one period of the signal. |
| Global Variable | A variable defined outside of all functions, which can be accessed by any function in the program. |
| GND (Ground) | Pins on the Arduino board that are used to ground a circuit. |
| H-Bridge | An electronic circuit that can drive a motor in both directions. The L298 is an example of an H-Bridge IC. |
| I2C (Inter-Integrated Circuit) | A serial communication system for short distances, using two conductors: SCL (clock) and SDA (data). |
| ICSP (In-Circuit Serial Programming) | A tiny programming header for the Arduino, often referred to as an SPI (Serial Peripheral Interface), that can act as an expansion of the output. |
| IDE (Integrated Development Environment) | The ready-made software (Arduino IDE) used to write computer code and upload it to the physical Arduino board. |
| Interrupt | A signal that stops the current work of the processor to handle a more urgent task, executed via an Interrupt Service Routine (ISR). |
| Local Variable | A variable declared inside a function or block that can only be used by statements within that function or block. |
| loop() | One of the two required functions in an Arduino sketch. It loops consecutively, allowing the program to change and respond. |
| Microcontroller | The main integrated circuit (IC) on an Arduino board, which can be considered the brain of the board. |
| pinMode() | A function used to configure a specific pin to behave either as an input or an output. |
| Potentiometer | An electro-mechanical transducer that converts rotary or linear motion into a change of resistance; a variable resistor. |
| Pull-up/Pull-down Resistor | A resistor used to steer an input pin to a known state (HIGH or LOW) if no input is present. |
| PWM (Pulse Width Modulation) | A technique used to vary the width of pulses in a pulse-train to control the power delivered to devices like LEDs or motors. |
| RX/TX LEDs | LEDs on the Arduino board that indicate receiving (RX) and transmitting (TX) of serial data. |
| Serial Communication | A communication method that transfers data one bit at a time. Arduino boards often use UART, I2C, and SPI for serial communication. |
| Servo Motor | A small device with an output shaft that can be positioned to specific angular positions (typically 0-180 degrees) by sending it a coded signal. |
| setup() | One of the two required functions in an Arduino sketch. It is called when a sketch starts and is used to initialize variables, pin modes, etc. |
| Sketch | The name given to a program written for Arduino. |
| SPI (Serial Peripheral Interface) | A serial communication system that is full duplex and uses up to four conductors: SCK (clock), MOSI (master out), MISO (master in), and SS (slave select). |
| Stepper Motor | A brushless, synchronous motor which divides a full rotation into a number of discrete steps. |
| String (object) | A type of string in Arduino that is a construct containing both data and functions (methods) to manipulate text. It is easier to use than character arrays but consumes more memory. |
| UART (Universal Asynchronous Receiver/Transmitter) | A module for asynchronous serial communication, which relies on mechanisms like start bits, stop bits, and a set baud rate instead of a shared clock line. |
| Variable Scope | A property of variables that defines the region of the program where they can be accessed. Includes local, global, and formal parameter scopes. |
| Vin | A pin that can be used to power the Arduino board from an external power source. |
| volatile | A keyword used to declare variables that are shared between an ISR and the main program to ensure they are updated correctly. |
| Voltage Regulator | A component that controls the voltage given to the Arduino board and stabilizes the DC voltages used by the processor. |