Moving Glossary of Terms
Abstraction
The practice of focusing on essential details while hiding unnecessary complexity.
Example: Using a wheel() function to generate colors without needing to understand the underlying RGB math.
ADC
Analog-to-Digital Converter; a circuit that converts continuous voltage signals into digital numbers a microcontroller can process.
Example: The Raspberry Pi Pico uses an ADC to read the voltage from a potentiometer and control LED brightness.
Addressable LED
A light-emitting diode that can be individually controlled through programming, unlike traditional LEDs that turn on and off together.
Example: Each pixel in a NeoPixel strip is an addressable LED that can display a different color.
Algorithm
A step-by-step procedure for solving a problem or completing a task.
Example: The rainbow cycle algorithm calculates color values, assigns them to pixels, and repeats to create a moving rainbow effect.
Animation
A visual pattern that changes over time by updating LED colors and positions.
Example: The comet tail animation creates the appearance of movement by fading pixels behind a bright leading pixel.
Anode
The positive terminal of an electronic component where electrical current enters.
Example: Connect the longer leg of an LED (the anode) to the positive voltage supply.
ARM Cortex M0+
A type of processor designed for low-power microcontrollers.
Example: The Raspberry Pi Pico uses two ARM Cortex M0+ processors running at 133 MHz.
Array
An ordered collection of values stored under a single variable name and accessed by position number.
Example: The colors array (red, orange, yellow, green, blue, indigo, violet) stores seven rainbow color values.
Assignment
The operation of storing a value in a variable using the equals sign.
Example: The statement counter = 0 assigns the value zero to the variable named counter.
Autocomplete
A feature in programming software that suggests code as you type.
Example: Thonny's autocomplete shows available functions when you type strip. after creating a NeoPixel object.
Base
The control terminal of a transistor that allows a small current to control a larger current flow.
Example: Connecting a GPIO pin through a resistor to the base of an NPN transistor allows the microcontroller to switch LED noodles on and off.
Base Current
The small electrical current flowing into the base terminal of a transistor.
Example: A base current of 0.5 mA can control a collector current of 50 mA in a transistor with a gain of 100.
Battery
A device that stores electrical energy chemically and releases it as electrical current.
Example: A 3.7-volt LiPo battery can power a Raspberry Pi Pico and LED strip for portable projects.
Battery Capacity
The total amount of electrical energy a battery can store, measured in milliamp hours.
Example: A 2000 mAh battery can theoretically supply 2000 milliamps for one hour or 200 milliamps for ten hours.
Battery Charger
An electronic circuit that safely refills a rechargeable battery with electrical energy.
Example: The TC4056 chip is a battery charger that can charge a LiPo battery at up to 1 amp.
Battery Life
The duration a battery can power a device before requiring recharge or replacement.
Example: Calculate battery life by dividing battery capacity (2000 mAh) by current draw (200 mA) to get 10 hours.
Bench Power Supply
An adjustable laboratory device that provides controlled voltage and current for testing circuits.
Example: Set the bench power supply to 5 volts and 500 mA to safely test your LED strip circuit.
Bias Current
A small control current that sets the operating point of an electronic component.
Example: The bias current flowing into a transistor base determines whether the transistor is on or off.
Binary Data
Information represented using only two symbols, typically 0 and 1.
Example: The color value 255 is represented in binary data as 11111111.
Binary Encoding
The process of representing information using combinations of 0s and 1s.
Example: Use binary encoding to display numbers on an 8x8 matrix by treating each row as an 8-bit binary number.
Bit
The smallest unit of digital information, having a value of either 0 or 1.
Example: An 8-bit color value uses eight bits to represent 256 different brightness levels from 0 to 255.
Blink
A pattern where LEDs turn on and off repeatedly at regular intervals.
Example: The first lesson creates a simple blink pattern by turning the first pixel red for one second, then off for one second.
Boolean
A data type with only two possible values: True or False.
Example: The boolean expression counter > 10 evaluates to True when the counter variable exceeds 10.
BOOTSEL Button
A button on the Raspberry Pi Pico that enters USB mass storage mode when held during power-up.
Example: Hold the BOOTSEL button while connecting USB to program the Pico by dragging a UF2 file.
Bootloader
A small program that runs when a device powers on and loads the main operating system or firmware.
Example: The Pico's bootloader allows you to program it by copying files when in BOOTSEL mode.
Branch
A separate version of code in a repository that allows changes without affecting the main version.
Example: Create a new branch in GitHub to experiment with a new animation pattern before merging it into the main code.
Breadboard
A plastic board with interconnected holes for building temporary electronic circuits without soldering.
Example: Insert the Pico into a breadboard to easily connect it to buttons and LED strips with jumper wires.
Brightness
The intensity of light emitted by an LED, typically controlled by the magnitude of color values.
Example: Reduce brightness by scaling all RGB values by 0.5, changing (255, 0, 0) to (128, 0, 0).
Buck Converter
An electronic circuit that efficiently reduces voltage while maintaining power.
Example: A buck converter converts 5 volts from USB to 3.3 volts for the microcontroller more efficiently than a resistor.
Candle Flicker
An animation pattern that simulates a flame by randomly varying orange and yellow colors.
Example: The candle flicker function randomly sets pixels to yellow or red-orange values to create a realistic fire effect.
Castellated Module
A circuit board with half-circle holes along the edges for surface-mount soldering.
Example: The RP2040-Zero is a castellated module that can be soldered directly onto a larger board.
Cathode
The negative terminal of an electronic component where electrical current exits.
Example: The shorter leg of an LED is the cathode and should be connected to ground.
Charging Current
The electrical current flowing into a battery during the charging process.
Example: The IP2312 charger supplies a charging current of up to 3 amps to quickly recharge LiPo batteries.
Charging Efficiency
The percentage of electrical energy that successfully enters a battery versus what is lost as heat.
Example: A charging efficiency of 85% means 15% of the power is wasted as heat during charging.
Circuit
A complete path through which electrical current can flow from positive to negative terminals.
Example: A basic LED circuit includes a power source, current-limiting resistor, LED, and connection back to ground.
Clock Speed
The rate at which a processor executes instructions, measured in megahertz or gigahertz.
Example: The RP2040 runs at a clock speed of 133 MHz, executing 133 million operations per second.
Clone
The action of creating a complete local copy of a remote code repository.
Example: Clone the Moving Rainbow repository from GitHub to download all lessons and example code to your computer.
Collector
The output terminal of an NPN transistor where controlled current flows to the load.
Example: Connect the LED noodle string to the collector of the transistor to switch them on and off.
Collector Current
The electrical current flowing through the collector terminal of a transistor.
Example: If the collector current is 50 mA and the LED noodles are at 3 volts, they consume 150 milliwatts of power.
Color Value
A number from 0 to 255 representing the intensity of a single color component.
Example: In the RGB tuple (255, 128, 0), the red color value is 255 (maximum), green is 128 (medium), and blue is 0 (off).
Color Wheel
A circular arrangement of colors showing smooth transitions through the visible spectrum.
Example: The wheel() function takes a number from 0 to 255 and returns an RGB color from the color wheel.
Color Wipe
An animation that fills the LED strip with a single color, one pixel at a time.
Example: The color wipe function uses a for loop to set each pixel to red sequentially with a short delay between them.
Comet Tail
An animation pattern featuring a bright leading pixel followed by progressively dimmer pixels creating a trailing effect.
Example: The comet tail animation uses brightness levels (255, 128, 64, 32, 16, 8, 4, 2, 1) to create a fading trail behind the moving pixel.
Comment
Text in code that is ignored by the computer but helps humans understand what the code does.
Example: The line # turn the first pixel on is a comment explaining the next line of code.
Commit
A saved set of changes to code with a description of what was modified.
Example: After fixing a bug in the rainbow function, create a commit with the message "Fixed rainbow color calculation".
Comparison
An operation that checks the relationship between two values, such as equal to, greater than, or less than.
Example: The comparison counter < NUMBER_PIXELS returns True when the counter is less than the total number of pixels.
Computational Thinking
A problem-solving approach that uses concepts from computer science to break down and solve problems.
Example: Use computational thinking to design a new LED pattern by decomposing it into smaller steps, recognizing color patterns, and creating an algorithm.
Concept Cards
Single-topic educational cards that teach one specific concept or skill.
Example: Each lesson in Moving Rainbow acts like a concept card, focusing on one animation technique such as moving pixels or color wheels.
Conditional
A programming construct that executes different code based on whether a condition is true or false.
Example: Use a conditional if mode == 0: to run the rainbow animation only when mode equals zero.
Constant Current
A power supply mode that maintains a fixed current regardless of voltage changes.
Example: A battery charger runs in constant current mode to safely charge a battery at 500 mA.
Constant Voltage
A power supply mode that maintains a fixed voltage regardless of current draw.
Example: USB provides constant voltage at 5 volts whether you draw 100 mA or 500 mA.
Current
The flow of electrical charge through a conductor, measured in amperes.
Example: An LED strip drawing 300 milliamps requires a current of 0.3 amperes from the battery.
Current Draw
The amount of electrical current a device consumes during operation.
Example: Calculate total current draw by multiplying the number of pixels (30) by the current per pixel (60 mA) to get 1800 mA.
Current Gain
The ratio of output current to input current in a transistor, also called beta.
Example: A transistor with current gain of 100 allows a 1 mA base current to control a 100 mA collector current.
Current Limiting Resistor
A resistor placed in series with a component to prevent excessive current flow.
Example: Place a 220-ohm current limiting resistor between a GPIO pin and LED to prevent damage.
Current Monitor
A device or circuit that measures the electrical current flowing through a conductor.
Example: Use a current monitor to verify that your LED strip is drawing the expected 1.8 amps.
Curriculum
A structured plan of educational content organized by topic and difficulty.
Example: The Moving Rainbow curriculum progresses from simple blink patterns to complex multi-mode animations.
Data Line
A wire or connection that carries information signals rather than just power.
Example: The middle wire of the JST connector is the data line that sends color commands to the NeoPixel strip.
Data Signal
An electrical signal that carries information encoded as voltage changes.
Example: The Pico sends a data signal to the LED strip containing color values for each pixel.
Data Transmission
The process of sending information from one device to another.
Example: Data transmission from the Pico to the LED strip happens serially, one bit at a time at high speed.
Data Type
A category that defines what kind of information a variable can store.
Example: Common data types include integers for whole numbers, floats for decimals, and strings for text.
DC Voltage
Direct Current voltage that flows in only one direction with constant polarity.
Example: Batteries provide DC voltage, unlike household outlets which provide alternating current.
Debugging
The process of finding and fixing errors in code or circuits.
Example: Use print statements for debugging to see which values variables contain when your animation doesn't work correctly.
Decrement
The operation of reducing a variable's value by one or a specified amount.
Example: The statement mode -= 1 decrements the mode variable by one when button 2 is pressed.
Deep Linking
A URL that points to a specific section within a webpage rather than just the page itself.
Example: Use deep linking to share the exact location in the documentation where the rainbow cycle function is explained.
Delay
A pause in program execution for a specified duration.
Example: Add a delay of 0.05 seconds between pixel updates to control animation speed.
Device ID
A unique number that identifies a specific piece of hardware.
Example: Each USB device has a device ID that helps the computer recognize what type of device is connected.
Diode
An electronic component that allows electrical current to flow in only one direction.
Example: The 1N4007 diode prevents reverse current from damaging the circuit if battery polarity is reversed.
Drag-and-Drop Programming
A method of programming by copying a file to a device appearing as a USB drive.
Example: Program the Pico using drag-and-drop programming by copying a UF2 file to the RPI-RP2 drive.
Dual-Core
A processor containing two independent processing units that can run tasks simultaneously.
Example: The RP2040 is dual-core, allowing it to run two programs at the same time.
Duty Cycle
The percentage of time a signal is in the "on" state during a cycle.
Example: A PWM signal with 75% duty cycle is on for three-quarters of each cycle, creating bright LED output.
Edge Pinout
The arrangement of connection pins along the edges of a circuit board.
Example: The Pico's edge pinout has 20 pins on each side, labeled with their GPIO numbers.
Emitter
The ground-connected terminal of an NPN transistor.
Example: Connect the emitter of the transistor to the circuit ground for proper operation.
Externally Powered
A device receiving electrical power from a wall adapter rather than a computer or battery.
Example: Use an externally powered USB hub when connecting multiple LED strips to avoid overloading your computer's USB ports.
Fade
A gradual change in LED brightness, either increasing or decreasing over time.
Example: The heartbeat pattern uses a fade to smoothly transition from dim to bright and back.
Fairy Lights
Lightweight LED strings commonly used for costumes and decorations.
Example: Sew fairy lights into Halloween costumes because they are flexible and battery-powered.
File System
The organizational structure for storing and retrieving files on a storage device.
Example: The Pico's file system stores your Python programs and config.py file in flash memory.
Firmware
Software that is permanently programmed into a hardware device to control its basic functions.
Example: Update the Pico's firmware to the latest version of MicroPython to access new features.
Flash Memory
Non-volatile storage that retains data when power is removed.
Example: The Pico has 2 MB of flash memory to store your Python programs permanently.
Floating Point
A data type for representing decimal numbers with fractional parts.
Example: The floating point value 0.05 represents a 50 millisecond delay when used with the sleep function.
For Loop
A programming loop that repeats code a specific number of times, often counting through a range.
Example: Use a for loop for i in range(30): to set colors for all 30 pixels in the strip.
Fork
Creating a personal copy of someone else's repository on GitHub that you can modify.
Example: Fork the Moving Rainbow repository to create your own version where you can add custom animations.
Forward Voltage Drop
The voltage consumed by a component when current flows through it in the correct direction.
Example: A diode has a forward voltage drop of about 0.7 volts, reducing the voltage available to other components.
Function
A named block of code that performs a specific task and can be reused multiple times.
Example: Define a function def move_dot(counter, color, delay): to encapsulate the moving dot animation code.
Gamma Correction
An adjustment to brightness values that compensates for non-linear human perception of light.
Example: Apply gamma correction using a lookup table so brightness changes appear smooth to the human eye.
Gamma Table
A predefined list of adjusted brightness values used for gamma correction.
Example: A gamma table maps linear values 0-255 to corrected values that appear evenly spaced to human vision.
GitHub
An online platform for storing, sharing, and collaborating on code projects.
Example: The Moving Rainbow project is hosted on GitHub at http://github.com/dmccreary/moving-rainbow.
GitHub Pages
A free website hosting service provided by GitHub for project documentation.
Example: The Moving Rainbow documentation website is published using GitHub Pages at http://dmccreary.github.io/moving-rainbow.
Global Variable
A variable that can be accessed and modified from anywhere in a program.
Example: Declare global mode inside a function to modify the mode variable defined outside the function.
GPIO
General Purpose Input/Output; programmable pins on a microcontroller that can send or receive electrical signals.
Example: GPIO pin 0 on the Pico is commonly used as the data output for NeoPixel strips.
Ground
The reference point in a circuit for voltage measurements, typically the negative terminal.
Example: Connect all black wires to ground (GND) to complete the electrical circuit.
Header Pins
Metal pins extending from a circuit board used for making electrical connections.
Example: Solder header pins to the Pico so it can be inserted into a breadboard.
Heat Dissipation
The process of transferring excess heat away from a component to prevent overheating.
Example: The TC4056 charger chip requires heat dissipation when charging at high current, which is why it gets warm.
Heat Sink
A metal component attached to electronics to improve heat dissipation.
Example: Attach a heat sink to the voltage regulator if it gets too hot when running many LEDs.
Heartbeat
An animation pattern that pulses LEDs brighter and dimmer to simulate a beating heart.
Example: The heartbeat function uses a fade in and fade out cycle with a brief pause between beats.
Hue
A pure color without considering brightness or saturation.
Example: Red, green, and blue are different hues, while pink and dark red are the same hue with different brightness and saturation.
I2C
Inter-Integrated Circuit; a communication protocol allowing multiple devices to communicate using two wires.
Example: Use the I2C protocol to connect multiple sensors to the Pico using only two GPIO pins.
IDE
Integrated Development Environment; software that provides tools for writing, testing, and debugging code.
Example: Thonny is a free IDE designed for Python programming with features like syntax highlighting and autocomplete.
If Statement
A conditional programming construct that executes code only when a specified condition is true.
Example: The if statement if counter > 15: runs the following code only when counter exceeds 15.
Import
A command that loads external code libraries or modules into a program.
Example: The statement import config loads the hardware configuration values from the config.py file.
Increment
The operation of increasing a variable's value by one or a specified amount.
Example: The statement counter += 1 increments the counter variable by one on each loop iteration.
Index
A number indicating the position of an item in a list or array, starting from zero.
Example: Access the first pixel using index 0 with strip[0] = (255, 0, 0).
Ingress Protection
A standardized rating system for water and dust resistance using IP codes.
Example: An IP67 rating means the LED strip is protected against dust and can be temporarily submerged in water.
Integer
A data type for whole numbers without decimal points.
Example: The integer value 30 represents the total number of pixels in the LED strip.
Interpreter
Software that reads and executes code one line at a time.
Example: The MicroPython interpreter running on the Pico translates your Python code into actions the processor can perform.
IP20
An ingress protection rating indicating no water resistance.
Example: Indoor LED strips are often IP20, suitable only for dry environments.
IP65
An ingress protection rating indicating water resistance from spray but not submersion.
Example: IP65 LED strips with silicon coating can be used outdoors but should not be submerged.
IP67
An ingress protection rating indicating waterproof protection allowing temporary submersion.
Example: IP67 LED strips in silicon tubes can be used underwater in fountains or pools.
Iteration
A single execution of code within a loop, or the process of repeating.
Example: Each iteration of the while loop updates the LED pattern and increments the counter.
JST Connector
A standardized 3-pin connector commonly used for LED strips with positive, data, and ground wires.
Example: Plug the JST connector from the LED strip into the matching socket on your controller board.
Kilohm
A unit of electrical resistance equal to 1,000 ohms.
Example: Use a 10 kilohm (10kΩ) potentiometer to adjust brightness or speed by varying resistance.
Larson Scanner
An animation pattern where a bright LED sweeps back and forth with a fading tail.
Example: The Larson Scanner effect, inspired by the Knight Rider TV show, creates a dramatic sweeping light pattern.
LED Noodle
A flexible filament LED designed for wearable projects, typically requiring 3 volts.
Example: LED noodles are ideal for Halloween costumes because they are lightweight and flexible.
LED Strip
A flexible strip containing multiple LEDs connected in series.
Example: A 30-pixel LED strip allows you to create animations by controlling each pixel individually.
Library
A collection of pre-written code that provides specific functionality.
Example: Import the neopixel library to access functions for controlling addressable LED strips.
Linear Charger
A battery charging circuit that regulates voltage using resistive elements, generating heat.
Example: A linear charger is simpler but less efficient than a buck converter for charging batteries.
Linear Dimmer
A brightness control method that directly scales LED values proportionally.
Example: A linear dimmer reduces (255, 0, 0) to (128, 0, 0) by multiplying by 0.5, though this doesn't appear half as bright to human eyes.
LiPo Battery
Lithium Polymer rechargeable battery known for high energy density and light weight.
Example: A 3.7-volt LiPo battery provides portable power for wearable LED projects.
List
Python's data structure for storing ordered collections of values that can be modified.
Example: Create a list of colors with colors = [red, orange, yellow, green, blue] to cycle through rainbow colors.
Local Variable
A variable that exists only within a specific function and cannot be accessed elsewhere.
Example: A local variable defined inside the move_dot() function is not accessible in other functions.
Loop
A programming construct that repeats a section of code multiple times.
Example: The main loop while True: runs continuously, updating the LED animation until the program is stopped.
Markdown
A simple text formatting language using symbols to create headers, lists, and emphasis.
Example: Write documentation in Markdown using #### for headers and **bold** for bold text.
Maximum Current
The highest electrical current a component can safely handle without damage.
Example: The GPIO pins have a maximum current of 16 mA, requiring transistors to control higher current loads.
Micro-USB
A small USB connector type commonly used for charging and programming.
Example: Connect the Pico to your computer using a micro-USB cable to upload programs and provide power.
Microcontroller
A small computer on a single chip designed to control electronic devices.
Example: The Raspberry Pi Pico is a microcontroller that runs your Python programs to control LED animations.
MicroPython
A version of Python optimized to run on microcontrollers with limited memory and processing power.
Example: MicroPython on the Pico lets you write LED control programs in Python instead of C++.
Microsecond
A unit of time equal to one-millionth of a second.
Example: NeoPixel timing uses microseconds to precisely control the data signals sent to each LED.
Millisecond
A unit of time equal to one-thousandth of a second.
Example: Set a delay of 50 milliseconds (0.05 seconds) between animation frames for smooth motion.
Milliamp
A unit of electrical current equal to one-thousandth of an ampere.
Example: Each NeoPixel draws up to 60 milliamps when displaying bright white.
Milliamp Hours
A unit of battery capacity indicating total charge storage.
Example: A 2000 milliamp hour battery can supply 1000 mA for 2 hours or 200 mA for 10 hours.
Milliwatt
A unit of power equal to one-thousandth of a watt.
Example: A single LED pixel at full brightness might consume 180 milliwatts of power.
MkDocs
A static website generator that creates documentation websites from Markdown files.
Example: The Moving Rainbow documentation is built using MkDocs and published to GitHub Pages.
Mode
A distinct operating state or pattern in a program, typically switched by user input.
Example: Press button 1 to increment the mode variable and switch from rainbow mode to comet tail mode.
Module
A file containing Python code that can be imported into other programs.
Example: The config module contains hardware pin assignments used by all lesson programs.
Modulo Function
A mathematical operation that returns the remainder after division.
Example: Use the modulo function counter % 30 to wrap the counter from 29 back to 0 for continuous animation.
Momentary Push Button
A button that makes electrical contact only while being pressed, returning to open when released.
Example: Wire a momentary push button between a GPIO pin and ground to create interactive controls.
Moving Rainbow
An animation pattern where a rainbow-colored band travels along the LED strip.
Example: The moving rainbow effect displays seven rainbow colors that shift position on each loop iteration.
NeoPixel
Adafruit's brand name for addressable RGB LED strips using WS2812B chips.
Example: Import the neopixel library to control NeoPixel strips with simple Python commands.
Normalized Value
A number scaled to fit within the range 0 to 1.
Example: Convert a brightness percentage to a normalized value by dividing by 100, so 75% becomes 0.75.
NPN Transistor
A type of transistor where a small positive current at the base controls larger current flow from collector to emitter.
Example: Use an NPN transistor like the 2N2222 to allow a GPIO pin to switch high-current LED loads.
Operator
A symbol representing a mathematical or logical operation.
Example: The operator + adds numbers, while * multiplies them, as in total = pixels * 60.
Overcurrent Protection
A safety circuit that automatically limits or stops current flow when it exceeds safe levels.
Example: USB ports have overcurrent protection that shuts off power if you try to draw more than 500 mA.
Overcharge Protection
A safety circuit that prevents battery damage by stopping charging when the battery is full.
Example: The TC4056 charger has overcharge protection that stops at 4.2 volts to extend LiPo battery life.
Parallel Circuit
An electrical circuit where components are connected across the same voltage with multiple current paths.
Example: In a parallel circuit, each LED branch receives the full battery voltage independently.
Parameter
A value passed into a function to customize its behavior.
Example: The function move_dot(counter, color, delay) accepts three parameters: position, color, and timing.
Pattern
A repeating design or sequence in an animation.
Example: The theater chase pattern creates a marquee effect by turning on every third LED and shifting the pattern.
Pattern Recognition
The ability to identify similarities and recurring elements in problems or data.
Example: Use pattern recognition to notice that many animations follow the same structure: update pixels, write to strip, delay, repeat.
Photo-Sensor
A device that detects the presence or intensity of light.
Example: Connect a photo-sensor to an analog pin to make LEDs automatically brighten when room lighting dims.
Photoresistor
A component whose electrical resistance changes based on the amount of light hitting it.
Example: Use a photoresistor in a voltage divider to create a nightlight that turns on in darkness.
PIO
Programmable Input/Output; specialized hardware on the RP2040 for creating custom timing-critical protocols.
Example: The NeoPixel library uses PIO state machines to generate precisely-timed data signals.
Pixel
An individual controllable LED unit in an addressable LED strip.
Example: Set pixel 5 to blue with the command strip[5] = (0, 0, 255).
Potentiometer
A variable resistor with an adjustable knob used to control electrical resistance.
Example: Connect a 10kΩ potentiometer to an analog pin to create a manual brightness control for your LED strip.
Power Consumption
The amount of electrical energy a device uses per unit of time.
Example: Calculate power consumption by multiplying voltage (5V) by current (1.8A) to get 9 watts.
Power Dissipation
The conversion of electrical energy into heat within a component.
Example: A current-limiting resistor has power dissipation calculated by squaring the current and multiplying by resistance.
Power Rating
The maximum amount of power a component can safely handle.
Example: Check the power rating of resistors to ensure they can handle the expected power dissipation without overheating.
Power Supply
A device that provides electrical energy to other components.
Example: Connect a 5-volt power supply capable of 2 amps to safely power a 30-pixel LED strip at full brightness.
Preamble
The beginning section of a program containing import statements and initial setup code.
Example: The preamble of most lessons imports the machine, neopixel, and config modules.
Product ID
A number that identifies the specific model or type of a device.
Example: The Raspberry Pi Pico has a unique product ID that helps your computer recognize it as a MicroPython device.
Pull
The action of downloading the latest changes from a remote repository.
Example: Pull updates from the Moving Rainbow repository to get new lessons and bug fixes.
Push
The action of uploading your local code changes to a remote repository.
Example: After adding a new animation, push your changes to GitHub to share them with others.
PWM
Pulse Width Modulation; a technique for controlling power by rapidly switching between on and off states.
Example: Use PWM to dim non-addressable LEDs by varying the duty cycle from 0% (off) to 100% (full brightness).
Python
A high-level programming language known for readability and ease of learning.
Example: MicroPython is a compact version of Python designed to run on microcontrollers.
Rainbow Cycle
An animation displaying all rainbow colors across the strip that rotates through the color spectrum.
Example: The rainbow cycle function uses the wheel function to assign different colors to each pixel based on position.
Range
A sequence of numbers generated for use in loops.
Example: The range range(0, 30) generates numbers from 0 to 29 for iterating through all pixels.
Raspberry Pi Foundation
A British educational charity that creates affordable computing devices for learning.
Example: The Raspberry Pi Foundation designed the Raspberry Pi Pico to teach physical computing.
Raspberry Pi Pico
A low-cost microcontroller board featuring the RP2040 chip and 26 GPIO pins.
Example: The Raspberry Pi Pico costs about $4 and is perfect for learning to control LEDs with MicroPython.
Recursive
A programming technique where a function calls itself to solve a problem.
Example: A recursive function can count down by calling itself with a decreased value until reaching zero.
Refresh Rate
The frequency at which a display updates its content.
Example: Update the LED strip at a refresh rate of 20 times per second (50 ms delay) for smooth animations.
Repository
A storage location for code and related files, typically on GitHub.
Example: Clone the Moving Rainbow repository to access all lesson code and documentation.
Resistance
Opposition to electrical current flow through a material, measured in ohms.
Example: A 220-ohm resistance limits current flow to safe levels for an LED.
Resistor
An electronic component that impedes current flow by a specified resistance.
Example: Connect a 220-ohm resistor in series with an LED to prevent excessive current.
Return Value
Data sent back from a function after it completes its task.
Example: The wheel function's return value is an RGB color tuple based on the input position.
Reverse Flow
Electrical current moving in the opposite direction from normal operation.
Example: A diode blocks reverse flow, protecting the circuit if battery polarity is accidentally reversed.
RGB
Red, Green, Blue; a color model mixing these three primary colors to create any visible color.
Example: Set a pixel to purple using RGB values (255, 0, 255) for maximum red and blue with no green.
RGB LED
A light-emitting diode containing separate red, green, and blue elements that can mix to produce any color.
Example: Each NeoPixel contains an RGB LED and control chip in a single 5mm square package.
Rhizomatic Learning
A non-linear educational approach where learners explore connections between topics in a network rather than following a fixed path.
Example: The Moving Rainbow project supports rhizomatic learning by allowing students to jump between lessons based on interest.
Ripple
An animation pattern creating expanding waves of color, like a stone dropped in water.
Example: The ripple effect starts at a center point and expands outward with fading brightness.
RP2040
The dual-core ARM Cortex M0+ microcontroller chip designed by Raspberry Pi Foundation.
Example: The RP2040 chip inside the Pico runs at 133 MHz and has 264KB of RAM.
RP2040-Zero
A compact development board featuring the RP2040 in a smaller form factor with castellated edges.
Example: The RP2040-Zero is half the size of a Pico, making it ideal for small wearable projects.
Runtime Library
Essential code that must be present for programs to execute properly.
Example: The MicroPython runtime library provides fundamental functions like print() and sleep().
Saturation
The intensity or purity of a color, from gray (low saturation) to vivid (high saturation).
Example: Pure red (255, 0, 0) has maximum saturation, while pink (255, 128, 128) has lower saturation.
Schematic
A diagram showing electrical connections using standardized symbols for components.
Example: Refer to the schematic to see which GPIO pin connects to the LED strip data line.
Scope
The region of code where a variable can be accessed.
Example: A variable defined inside a function has local scope and cannot be used outside that function.
Screw Headers
Terminal blocks with screws for securing wires without soldering.
Example: Use screw headers to make removable connections between the Pico and LED strip wires.
Serial Console
A text-based communication interface for interacting with a microcontroller.
Example: View print statement output in the serial console at the bottom of Thonny.
Serial Data
Information transmitted one bit at a time over a single wire.
Example: NeoPixels receive serial data containing color information at 800,000 bits per second.
Series Circuit
An electrical circuit where components are connected end-to-end in a single path.
Example: In a series circuit, current must flow through each component sequentially.
Short Circuit
An unintended connection creating a very low resistance path for current.
Example: Prevent short circuits by ensuring positive and negative wires never touch directly.
Signal Processing
The analysis and manipulation of electrical signals carrying information.
Example: The WS2812B chip performs signal processing to decode color data from the timing of voltage pulses.
Skill
A package of rules used by generative AI to help us generate content.
Example: We have a sample skill for you to generate LED strip patterns based on a high-level description such as "Generate patters for my Halloween party".
See Sample Skills
Sleep
A function that pauses program execution for a specified duration.
Example: The command sleep(0.1) pauses for one-tenth of a second between animation frames.
Solar Panel
A device that converts light energy into electrical energy.
Example: Connect a 6-volt solar panel to a battery charger circuit to create a self-powered nightlight.
Solderless Breadboard
Another term for breadboard, emphasizing that no soldering is required.
Example: Build prototype circuits quickly on a solderless breadboard before creating a permanent version.
SPI
Serial Peripheral Interface; a synchronous communication protocol using separate clock and data lines.
Example: Some LED matrices use the SPI protocol for faster data transmission than basic serial.
Spectrum
The range of all possible colors in order of wavelength.
Example: The rainbow displays the visible spectrum from red through violet.
SRAM
Static Random-Access Memory; fast temporary storage that retains data while powered.
Example: The RP2040 has 264KB of SRAM for storing variables while programs run.
State Machine
A programmable logic system that changes outputs based on inputs and current state.
Example: The PIO state machines in the RP2040 generate precise NeoPixel timing signals.
String
A data type representing text as a sequence of characters.
Example: Use a string like "rainbow mode" to display the current animation name.
Strip
The variable name commonly used to represent a NeoPixel LED strip object.
Example: Initialize the strip with strip = NeoPixel(Pin(0), 30) to create a 30-pixel strip on GPIO pin 0.
Sushi Cards
Bite-sized educational cards teaching single concepts, named after the CoderDojo project.
Example: Create sushi cards for each lesson showing the key concept and code snippet.
Syntax
The grammar rules that define how code must be written for a programming language.
Example: Python syntax requires consistent indentation and colons after if statements.
Syntax Highlighting
Automatic color-coding of different parts of code to improve readability.
Example: Thonny's syntax highlighting shows keywords in orange, strings in green, and comments in gray.
Tactile Switch
Another term for a momentary push button with tactile feedback when pressed.
Example: Wire tactile switches to GPIO pins 14 and 15 for interactive mode control.
Temperature Sensor
A device that measures heat and converts it to an electrical signal.
Example: The RP2040 includes a built-in temperature sensor you can read to monitor chip temperature.
Theater Chase
An animation pattern resembling marquee lights, with groups of LEDs moving along the strip.
Example: The theater chase function lights every third pixel and shifts the pattern to create a chasing effect.
Thermal Feedback
Automatic adjustment of operation based on temperature measurements.
Example: Battery chargers use thermal feedback to reduce charging current if the chip gets too hot.
Thonny
A free Python IDE designed for beginners with simple interface and built-in debugging tools.
Example: Use Thonny to write MicroPython programs and upload them to the Pico.
Tie Points
The individual connection holes in a breadboard that are electrically connected in groups.
Example: A half-size breadboard typically has 400 tie points arranged in rows of 5 connected holes.
Transistor
A semiconductor component that acts as an electronic switch or amplifier.
Example: Use a transistor to let a low-current GPIO pin control high-current LED noodles.
Trickle Charge
A very small charging current used to maintain a battery without overcharging.
Example: After a battery is full, the charger switches to trickle charge mode to keep it topped off.
Tuple
An ordered, immutable collection of values in Python.
Example: RGB colors are stored as tuples like (255, 0, 0) where the values cannot be changed individually.
Twinkle
An animation pattern with random pixels blinking on and off to simulate stars.
Example: The twinkle effect randomly selects pixels and sets them to white before fading them out.
UART
Universal Asynchronous Receiver-Transmitter; a protocol for serial communication between devices.
Example: The Pico uses UART protocol to send print statement output to your computer via USB.
UF2 Format
USB Flashing Format; a file type for programming microcontrollers by copying to a USB drive.
Example: Download the MicroPython UF2 file and drag it to the RPI-RP2 drive to program the Pico.
USB Connector
A standardized plug for connecting devices, providing both power and data communication.
Example: Plug a USB connector into your computer to program the Pico and power the LED strip.
USB Device
Any hardware that connects to a computer through a USB port.
Example: The Pico appears as a USB device when connected, allowing file transfer and serial communication.
USB Hub
A device that expands one USB port into multiple ports.
Example: Use an externally powered USB hub to connect multiple LED projects without overloading your computer's USB ports.
USB Power Pack
A portable battery with USB output for charging devices.
Example: A 10,000 mAh USB power pack can run a 30-pixel LED strip for several hours.
USB-C
The newest reversible USB connector type supporting higher power and data rates.
Example: Some newer development boards use USB-C instead of micro-USB for more reliable connections.
Variable
A named storage location in a program that holds a value which can change.
Example: Create a variable counter = 0 to keep track of the current pixel position in an animation.
Vendor ID
A unique number assigned to each manufacturer of USB devices.
Example: All Raspberry Pi products share the same vendor ID, helping computers recognize them.
Voltage
The electrical potential difference between two points, measured in volts.
Example: The Pico operates at 3.3 volts for logic signals while most LED strips require 5 volts.
Voltage Regulator
A circuit that maintains constant output voltage despite changes in input voltage or current draw.
Example: A voltage regulator converts 5V from USB down to 3.3V for the Pico's processor.
Watt
A unit of electrical power equal to one joule per second.
Example: A 30-pixel LED strip at full brightness consumes approximately 1.8 watts of power.
Waterproofing
Protection that prevents water from entering or damaging electronics.
Example: Choose waterproofing level based on use: IP20 for indoors, IP65 for outdoor, IP67 for underwater.
Wheel Function
A function that converts a number from 0-255 into an RGB color, cycling through the spectrum.
Example: Call wheel(128) to get a cyan color halfway through the color wheel.
While Loop
A loop that continues executing as long as a specified condition remains true.
Example: The main animation loop while True: runs forever because the condition True never becomes false.
Wiring Diagram
A simplified drawing showing physical connections between components.
Example: Follow the wiring diagram to connect the LED strip's red wire to 5V, black to ground, and green to GPIO pin 0.
Write
The command that sends color data from the program to the physical LED strip.
Example: After setting pixel colors, call strip.write() to make the changes visible on the strip.
WS2812B
The specific integrated circuit chip standard used in addressable RGB LEDs.
WS2812B are also known as NeoPixels.
Example: WS2812B chips contain an RGB LED and control circuitry in a single 5mm package, allowing individual addressing of each pixel.