TopicLadder
Resource index

Maker Ladders

Every public TopicLadder route from a starting point to a practical maker outcome.

How to choose a ladder

Start with the project you are trying to move forward. If the project needs a live website, use Linux, DNS, Nginx, Git, and VPS ladders. If it needs a playable prototype, use the Godot path. If it needs a physical signal, use electronics, measurement, and sensor ladders. If it needs equipment reading, start with hydraulic schematic and pressure/flow ladders. Each card below points back to a project, note, deck, practice asset, and next ladder.

Linux Command Line Foundations for Makers

What you will understand: Open a terminal, find files, read output, and run small inspection commands with confidence.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: Linux Command Line Foundations for Makers

Learn enough shell navigation, reading, and command composition to inspect a project machine without blindly pasting commands. pwd, ls, and cat tell you where you are and what file you are reading before you change anything. Create a small folder with two text files. Use pwd, ls -lah, head, and grep to answer where the files are and what each contains. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Nginx Static Site Basics for Makers

What you will understand: Understand the path from a local HTML file to a live HTTPS page on a VPS.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: Nginx Static Site Basics for Makers

Learn how Nginx serves a static site from a document root, why release folders help, and how to verify a deploy safely. nginx -t proves configuration syntax before reload. Sketch a release layout with releases/YYYYMMDDTHHMMSSZ and current. Explain how rollback would work. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

DNS Records and SSL for Makers

What you will understand: Connect a domain to a VPS without guessing whether the problem is DNS, Nginx, or TLS.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: DNS Records and SSL for Makers

Learn the practical order for pointing a domain at a VPS, checking DNS, proving HTTP, and adding HTTPS. dig +short domain A shows the public A record answer. Write the sequence you would use to connect a new domain to an existing VPS, including the command that proves each step. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Linux Files and Permissions for Makers

What you will understand: Diagnose why a project file cannot be read, executed, or served.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: Linux Files and Permissions for Makers

Learn paths, owners, groups, modes, and parent directory traversal before changing chmod or chown. namei -l /path/to/file walks every path component. Build a test directory where only the parent execute bit is wrong. Use namei -l to identify the break. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Search Logs with grep, find, and tail

What you will understand: Find the relevant log lines for a recent failure without reading the whole log directory.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: Search Logs with grep, find, and tail

Learn how to search project logs by scope, time, and symptom so debugging starts from evidence. tail -80 logfile reads a bounded slice before deeper searching. Given a failing service name, list three bounded commands you would run before opening a huge log. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Git Workflow for Small Projects

What you will understand: Make a small project safer to edit, deploy, and roll back.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: Git Workflow for Small Projects

Use Git to inspect changes, commit one idea at a time, tag releases, and keep rollback possible. git status shows what changed before you commit or deploy. Change one line in a sample file, inspect it with git diff, stage it, and write a commit message that describes only that change. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Linux Disk Space and Logs for Makers

What you will understand: Identify whether a disk-full problem is bytes, inodes, journal logs, Docker, or deleted-open files.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: Linux Disk Space and Logs for Makers

Learn how bytes, inodes, logs, and deleted-open files can each make a project machine look full. df -h and df -i separate byte pressure from inode pressure. Write a five-command disk-full triage checklist and explain what each command proves. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

SSH Keys and Known Hosts for Makers

What you will understand: Debug SSH access without exposing private keys or blindly removing known_hosts entries.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: SSH Keys and Known Hosts for Makers

Learn how SSH identity, authorized keys, host keys, and file modes fit together before deleting warnings. ssh -vvv user@host shows which authentication step fails. Describe how you would tell apart a publickey failure from a changed host key warning. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Python Virtual Environments for Makers

What you will understand: Run a project with the intended Python interpreter and dependency set.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: Python Virtual Environments for Makers

Learn why Python projects use virtual environments and how to prove which interpreter and packages are active. python -V and which python show which interpreter your shell will use. Create a tiny venv, install one package, and prove which python and pip are active. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Godot First Playable Loop

What you will understand: Create a tiny game loop with input, movement, collision, a goal, and reset.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Godot First Playable Loop

Build the smallest playable loop before adding art, menus, inventory, or online systems. Write the player action in one sentence before adding systems. Make a one-room prototype where a test player reaches a goal and resets. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Sprite-Animated 2D Game Loop

What you will understand: Create one playable 2D proof with animated player states, tile collision, a goal, and a repeatable export check.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Sprite-Animated 2D Game Loop

Build a tiny Godot 4 scene where one sprite moves, animates, collides with a tile room, reaches a goal, and resets. Write the verb, sprite states, tile size, and one-room proof before adding art polish or extra mechanics. Use the widget to choose frames, FPS, tile size, room size, and movement speed. Copy the note, then make one Godot scene that proves those numbers. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

Related project · Deck · Note · Practice asset · Next ladder

Tilemap Level Layout Math

What you will understand: Sketch and build a one-room Godot tilemap where the player can see the route, collide with solid cells, reach a goal, and explain the scale.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Tilemap Level Layout Math

Use tile size, room dimensions, camera view, collision cells, and traversal time to design one readable 2D room before painting a large map. Write tile size, viewport size, room tile count, solid/passable cell rules, and one route before decorating the map. Use the widget to choose tile size, room dimensions, viewport size, and movement speed. Copy the note, then build one room with floor, wall, gap, goal, and camera limits. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

Related project · Deck · Note · Practice asset · Next ladder

Collision Normal Bounce Math

What you will understand: Build a one-wall Godot bounce proof where incoming velocity, collision normal, outgoing velocity, and energy loss are visible.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Collision Normal Bounce Math

Use vectors, surface normals, and restitution to make one 2D bounce predictable before building a whole physics-heavy game. Sketch one contact: incoming arrow, surface normal, reflected arrow, and the value that proves the bounce is repeatable. Use the widget to choose incoming velocity, normal angle, and restitution. Copy the note, then reproduce one wall bounce in a tiny Godot scene. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

2D Transform Stack for Sprites

What you will understand: Place one child sprite from a local offset, predict its world position, and explain why parent rotation or scale moved it.

What you can build with it: Build a First Godot Game Loop

Recommended first page: 2D Transform Stack for Sprites

Use local space, parent transforms, rotation, scale, and pivot checks to place sprite attachments without dragging things by eye. Create one parent marker and one child sprite, then write the child's local offset before changing the parent transform. Use the widget to choose a parent transform and child local offset. Copy the note, then build one parent marker and child sprite in Godot. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

Related project · Deck · Note · Practice asset · Next ladder

Projectile Arc Tuning for Godot

What you will understand: Build a one-launch Godot proof where the predicted arc, actual projectile path, first hit, and tuning notes can be compared.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Projectile Arc Tuning for Godot

Use launch angle, speed, gravity, and time steps to sketch a projectile arc before tuning a cannon, thrown item, jump shot, or ball path by feel. Sketch one launch point, one target, one gravity value, and one time window before adding effects or enemies. Use the widget to choose angle, speed, gravity, and time. Copy the note, then build one projectile scene and compare the preview arc to the actual hit. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

Related project · Deck · Note · Practice asset · Next ladder

Microcontroller Wiring First Checks

What you will understand: Inspect a simple controller circuit with less guesswork and fewer fried parts.

What you can build with it: Wire a Sensor to a Microcontroller

Recommended first page: Microcontroller Wiring First Checks

Learn the first checks before blaming firmware: power, ground, pin mapping, signal direction, and measurement points. Disconnect power before changing wiring, then verify voltage before connecting a device. Draw a three-wire sensor connection and mark power, ground, signal, expected voltage, and measurement point. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Hydraulic Schematic First Read

What you will understand: Explain what a basic hydraulic circuit is trying to do before touching equipment.

What you can build with it: Read a Hydraulic Schematic

Recommended first page: Hydraulic Schematic First Read

Learn a first-pass method for reading hydraulic schematics: source, actuator, valve, flow path, pressure limit, and safe stop. Identify the energy source and stored-energy hazards before tracing the circuit. On a simple cylinder circuit drawing, mark pump, tank, valve, actuator, relief, extend path, and retract path. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Godot Input Actions First Pass

What you will understand: Make input remapping and controller support easier later.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Godot Input Actions First Pass

Map player intent to actions before wiring controls directly to keys. Create action names before binding keys. Create a small practice case for godot input actions first pass and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Godot Collision Debugging Basics

What you will understand: Debug a small collision problem without rewriting the whole player controller.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Godot Collision Debugging Basics

Find why game objects pass through, stick, or never trigger collisions. Turn on visible collision shapes before changing physics code. Create a small practice case for godot collision debugging basics and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Game Save System First Draft

What you will understand: Save and reload one small game state without inventing a full account system.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Game Save System First Draft

Plan the first save file around the minimum state needed to resume a prototype. List the exact state that must survive closing the game. Create a small practice case for game save system first draft and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Multimeter First Measurements

What you will understand: Use a meter to answer a circuit question instead of guessing.

What you can build with it: Wire a Sensor to a Microcontroller

Recommended first page: Multimeter First Measurements

Learn the first safe multimeter checks: voltage, continuity, resistance, and current caution. Set the meter mode before touching the probes to the circuit. Create a small practice case for multimeter first measurements and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Read a Datasheet First Pass

What you will understand: Find voltage, pinout, absolute maximums, and typical application notes.

What you can build with it: Wire a Sensor to a Microcontroller

Recommended first page: Read a Datasheet First Pass

Extract the first useful facts from a component datasheet without reading every page. Find the part number and package before trusting a pinout. Create a small practice case for read a datasheet first pass and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Motor Driver First Checks

What you will understand: Bring up a small motor driver safely enough to test direction and speed.

What you can build with it: Wire a Sensor to a Microcontroller

Recommended first page: Motor Driver First Checks

Check power, ground, enable pins, signal voltage, and load wiring before blaming firmware. Disconnect the motor until logic power and driver wiring are understood. Create a small practice case for motor driver first checks and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Stepper Motor Wiring First Checks

What you will understand: Wire a small stepper motor without randomly swapping leads.

What you can build with it: Wire a Sensor to a Microcontroller

Recommended first page: Stepper Motor Wiring First Checks

Identify stepper coil pairs, driver connections, current limits, and direction before tuning motion. Find the two coil pairs before connecting the driver. Create a small practice case for stepper motor wiring first checks and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

CAD Constraints First Sketch

What you will understand: Create a simple sketch that survives later changes.

What you can build with it: Build an Obsidian Project Notebook

Recommended first page: CAD Constraints First Sketch

Use constraints and dimensions to make a sketch editable instead of fragile. Define the design intent before adding every dimension. Create a small practice case for cad constraints first sketch and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Measure Fastener Threads

What you will understand: Avoid mixing similar-looking fasteners that do not actually fit.

What you can build with it: Build an Obsidian Project Notebook

Recommended first page: Measure Fastener Threads

Identify diameter, pitch, length, and head style before ordering or replacing a fastener. Clean and inspect the fastener before measuring it. Create a small practice case for measure fastener threads and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Welding First Safety Checklist

What you will understand: Prepare a safe practice weld area before learning bead control.

What you can build with it: Build an Obsidian Project Notebook

Recommended first page: Welding First Safety Checklist

Walk through PPE, ventilation, fire watch, material prep, and machine setup before striking an arc. Confirm PPE, ventilation, and nearby combustibles before power-on. Create a small practice case for welding first safety checklist and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Hydraulic Cylinder Leak First Checks

What you will understand: Describe a cylinder leak clearly before ordering parts or disassembling equipment.

What you can build with it: Read a Hydraulic Schematic

Recommended first page: Hydraulic Cylinder Leak First Checks

Separate external seal leaks, fitting leaks, hose damage, and internal bypass symptoms. Depressurize and make the equipment safe before inspection. Create a small practice case for hydraulic cylinder leak first checks and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Hydraulic Pressure vs Flow

What you will understand: Explain why a slow actuator and a weak actuator are not the same symptom.

What you can build with it: Read a Hydraulic Schematic

Recommended first page: Hydraulic Pressure vs Flow

Understand the difference between pressure, flow, force, and speed in a hydraulic system. Identify whether the complaint is force, speed, heat, or noise. Create a small practice case for hydraulic pressure vs flow and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Robot Drivetrain First Prototype

What you will understand: Drive a platform forward, backward, and turn reliably.

What you can build with it: Build an Obsidian Project Notebook

Recommended first page: Robot Drivetrain First Prototype

Build the smallest drivetrain test before adding sensors, autonomy, or payload. Test motors off the ground before adding load. Create a small practice case for robot drivetrain first prototype and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Sensor Mounting First Pass

What you will understand: Mount a sensor so it can produce useful readings after the robot moves.

What you can build with it: Build an Obsidian Project Notebook

Recommended first page: Sensor Mounting First Pass

Plan sensor field of view, vibration, cable strain, and calibration access before printing brackets. Write what the sensor must see before designing the bracket. Create a small practice case for sensor mounting first pass and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Small Engine No-Start First Checks

What you will understand: Describe a no-start problem in evidence terms.

What you can build with it: Build an Obsidian Project Notebook

Recommended first page: Small Engine No-Start First Checks

Use a basic fuel, spark, air, and safety-interlock sequence before replacing parts. Make the machine safe and follow the manual before inspection. Create a small practice case for small engine no-start first checks and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Make an Obsidian Project Note

What you will understand: Keep one project note that actually helps you resume work.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: Make an Obsidian Project Note

Turn a project idea into a reusable note with goal, prerequisites, sources, decisions, and next action. Write the next physical or technical action in one sentence. Create a small practice case for make an obsidian project note and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Turn a Video into Flashcards

What you will understand: Make five review cards that preserve the useful lesson from a video.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: Turn a Video into Flashcards

Convert a useful video into notes and cards without copying noise. Watch for decisions, warnings, and output interpretation, not just vocabulary. Create a small practice case for turn a video into flashcards and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build. If the next command, measurement, diagram, or sketch feels unclear, pause and write that question before moving on.

Related project · Deck · Note · Practice asset · Next ladder

Read a Project Error Message

What you will understand: Stop treating every error message as a wall of text.

What you can build with it: Deploy a Static Site on a VPS

Recommended first page: Read a Project Error Message

Break an error into location, cause, expected state, and next test. Copy the exact first error line and the command that produced it. Create a small practice case for read a project error message and write what each step proves before moving to the next one. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Packet Radio with a Baofeng: Receive-First APRS Basics

What you will understand: Draw a receive-first packet-radio path and explain what a decoded packet proves without assuming transmit permission.

What you can build with it: Learn the command line for maker projects

Recommended first page: Packet Radio with a Baofeng: Receive-First APRS Basics

Understand packet radio and APRS with a Baofeng-class handheld by mapping the radio, audio path, decoder, packet fields, and license boundary before any transmit work. Start receive-only: identify the radio role, audio path, decoder, expected packet fields, and local rules before touching transmit. Draw a packet path for a receive-only Baofeng/APRS learning setup. Label radio, audio interface, decoder, packet fields, license boundary, and the exact point where you stop before transmit. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

Related project · Deck · Note · Practice asset · Next ladder

Antenna Length Math for Makers

What you will understand: Convert frequency into wavelength fractions, compare meters/feet/inches, apply a velocity factor, and explain why the result is only a starter estimate.

What you can build with it: Learn the command line for maker projects

Recommended first page: Antenna Length Math for Makers

Estimate wavelength, quarter-wave, and half-wave starter lengths from frequency before changing antennas, cutting wire, or trusting a build video. Stay receive-first unless you have the right authorization. Write frequency, units, antenna type, and tuning check before any transmit use. Enter one frequency into the calculator, copy the estimate note, then write full-wave, half-wave, quarter-wave, velocity factor, and the next verification step before any real build. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

Related project · Deck · Note · Practice asset · Next ladder

RSSI Mapping for Direction Finding

What you will understand: Record angle/RSSI pairs, plot a strongest lobe, and explain what the reading suggests without claiming exact source location.

What you can build with it: Learn the command line for maker projects

Recommended first page: RSSI Mapping for Direction Finding

Use receive-only signal-strength readings to sketch a direction clue, compare angles, and explain uncertainty before making any field claim. Use only lawful receive-only readings from your own test source or a signal you are allowed to monitor; do not track people or interfere with equipment. Enter eight angle/RSSI pairs in the widget, copy the Markdown note, then write whether the strongest direction is a clean peak, a broad lobe, or too noisy to trust. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

Related project · Deck · Note · Practice asset · Next ladder

SDR Flight Tracking: ADS-B First Pass

What you will understand: Name the ADS-B frequency, antenna role, receiver role, decoded fields, and map output without confusing receive-only learning with official tracking or transmitting.

What you can build with it: Learn the command line for maker projects

Recommended first page: SDR Flight Tracking: ADS-B First Pass

Use an RTL-SDR-style receiver to understand public ADS-B aircraft broadcasts: frequency, antenna, receiver, decoder, fields, map display, and the receive-only boundary. Stay receive-only. Identify the signal type, 1090 MHz frequency, antenna, receiver, decoder, field list, and lawful-use boundary before installing or sharing anything. Draw one receive-only ADS-B path. Label aircraft broadcast, 1090 MHz signal, antenna, RTL-SDR, decoder, decoded fields, map display, timestamp, and the limits of your claim. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

Related project · Deck · Note · Practice asset · Next ladder

Stepper Antenna Sweep for Direction Finding

What you will understand: Build a repeatable sweep plan: angle steps, antenna orientation, RSSI sample, strongest lobe, repeated run, and uncertainty note.

What you can build with it: Learn the command line for maker projects

Recommended first page: Stepper Antenna Sweep for Direction Finding

Connect trigonometry, a rotating fixture, and receive-only RSSI readings so a maker can sweep an antenna in known steps and write an honest bearing clue. Start receive-only with a lawful test signal and a hand sketch of the rotation before wiring a motor or making a location claim. Make a 12-stop sweep table at 30-degree increments. Sketch the arm, write two example RSSI runs, mark the strongest lobe, and explain what remains uncertain. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

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Motion Tracking with Vector Velocity

What you will understand: Compare two positions, compute the delta vector, divide by elapsed time, and explain speed and direction without hiding units or uncertainty.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Motion Tracking with Vector Velocity

Turn two position samples into direction, speed, and a useful motion note for games, robots, camera tracking, or sensor logs. Write the two positions, units, and elapsed time before calculating speed or smoothing the track. Enter a current point, target point, and speed in the graph widget. Then write the delta vector, length, unit direction, next position, and what extra samples you would need before trusting the motion. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

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Basic Statistics for Sensor Logs

What you will understand: Read a short sensor log and explain mean, median, range, standard deviation, outliers, and moving-average tradeoffs in project terms.

What you can build with it: Build an Obsidian project notebook

Recommended first page: Basic Statistics for Sensor Logs

Turn repeated maker readings into a small evidence note: typical value, noise width, suspicious jumps, and what to measure again. Keep the raw readings and units before smoothing, deleting, or explaining away a weird value. Take ten sample readings from a sensor, RSSI sweep, temperature probe, or simulated list. Write the mean, median, min, max, range, one suspicious reading, and the next repeat test. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

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Vectors for Maker Projects

What you will understand: Describe a movement, force, sensor direction, or offset as a vector and explain what the numbers mean.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Vectors for Maker Projects

Use vectors as arrows with size and direction so game movement, sensor orientation, force sketches, and layout offsets become inspectable. Draw the arrow first: start point, direction, length, and units before writing formulas or code. Sketch a small game object moving toward a target. Label current position, target position, direction vector, length, and unit direction. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Dot Product for Facing and Projection

What you will understand: Use dot product as a yes/no or how-much signal for facing, projection, lighting, and control problems.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Dot Product for Facing and Projection

Use dot product to answer practical questions: is one thing facing another, how much motion points forward, or how much light hits a surface. Normalize direction vectors first when you want an angle-like comparison instead of a size-weighted number. Draw a player forward arrow and a target direction arrow. Predict whether the dot product should be positive, near zero, or negative before calculating it. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

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Trigonometry for Rotation and Layout

What you will understand: Move between an angle, a side length, and a coordinate change without guessing.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Trigonometry for Rotation and Layout

Use sine, cosine, tangent, radians, and atan2 to turn angles into positions, rotations, slopes, and repeatable layout checks. Write whether the angle is in degrees or radians before using it in code, calculators, or sketches. Draw a rotating pointer, mark radius and angle, then compute where the tip should be for one simple angle. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

Related project · Deck · Note · Practice asset · Next ladder

Calculus for Game Motion

What you will understand: Connect position, velocity, acceleration, and frame time so a motion change can be predicted before it is tuned.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Calculus for Game Motion

Use slope, velocity, acceleration, area, and frame time to reason about game motion before tuning jumps, slides, camera movement, projectiles, or drone-style motion values. Write the axis, units, starting position, velocity, acceleration, and time step before changing a physics value. Use the widget with one jump or slide example. Change acceleration once, predict the graph, then copy the note and explain whether velocity or position changed first. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

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FFT Frequency Peaks First Pass

What you will understand: Compare a time signal with a frequency view and identify one dominant repeating pattern.

What you can build with it: Build an Obsidian project notebook

Recommended first page: FFT Frequency Peaks First Pass

Use a simple FFT-style frequency view to spot repeated patterns in audio, vibration, motor, sensor, or SDR-like logs without overclaiming the cause. Write the sample rate, units, recording length, sensor or source, and expected pattern before reading frequency peaks. Use the widget to create two tones, change sample rate once, copy the note, and explain which peak is useful and what remains uncertain. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

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Audio Spectrum Visualizer with FFT

What you will understand: Build a first-pass spectrum visualizer plan: source signal, sample rate, FFT bins, bar display, peak clue, and uncertainty note.

What you can build with it: Build an Obsidian project notebook

Recommended first page: Audio Spectrum Visualizer with FFT

Use FFT thinking to turn microphone, file, game-audio, or sensor samples into frequency bars without pretending the display proves more than it does. Write the audio or sensor source, sample rate, window length, units, display goal, and what the bars should not claim. Use the widget to make two tones and one noise note. Copy the visualizer note, then sketch a Godot, Python, or microcontroller display path with source, sample rate, bars, peak clue, and next repeat test. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action.

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Scale, Ratio, and Unit Conversions

What you will understand: Convert a drawing, measurement, or material estimate into the units the project actually needs.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Scale, Ratio, and Unit Conversions

Use ratios, scale factors, and unit conversions to move between drawings, material lists, sensor readings, and real dimensions. Write the starting unit and target unit before multiplying anything. Convert one small project dimension from a sketch into real size, then write the estimate, exact conversion, and a named tolerance. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

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Interpolation for Motion and Controls

What you will understand: Explain what start value, end value, and progress value produce a smooth transition.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Interpolation for Motion and Controls

Use interpolation to move between two values in a controlled way: animation, smoothing, servo targets, UI sliders, and parameter changes. Name the start, end, and progress value before choosing lerp, easing, or smoothing. Animate a number from 0 to 100 and write what t=0, t=0.25, t=0.5, and t=1 should produce before testing it. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

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Geometry for Cuts, Clearance, and Fit

What you will understand: Check a physical layout with diagonals, offsets, spacing, and clearance before making a permanent cut.

What you can build with it: Build a First Godot Game Loop

Recommended first page: Geometry for Cuts, Clearance, and Fit

Use simple geometry to reason about square corners, clearances, hole spacing, diagonal checks, and parts that need to fit before cutting material. Sketch the part and mark fixed edges, clearance zones, and measurement points before measuring diagonals. Draw a rectangular panel with two holes. Mark the reference edge, centerline, hole spacing, clearance, and diagonal check. Keep the note tied to a concrete maker project so the lesson does not become a saved link with no next action. After reading, choose one related lesson or practice task and produce a small proof that the idea works in your build.

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Last reviewed: July 5, 2026. TopicLadder pages are curated for practical learning and may be updated as examples improve.