Development Guide: Code a Mini Economy Town in Scratch

This guide explains how to build a dice-powered city simulator in Scratch. You will learn how to manage a virtual economy, use cloning to build a visual city, and create a multi-level progression system.

You can check out this project on Scratch. Dicy City Scratch

We made a more polished version here. Check out the YouTube video below.

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Step 1: The Economy Engine

The Goal: Create a dice-rolling mechanic that generates money.

• Setup Variables: Create variables for Coins, Dice Total, and Roll Count.
• The Dice Sprite:
  • Give your Dice sprite 6 costumes (one for each side).
  • When the sprite is clicked, use the pick random 1 to 6 block to set the Dice Total.
  • Switch the costume to match the number.
• The Payout System:
  • Use a Broadcast called Check Payout.
  • When the dice stops rolling, send the broadcast. Every building you own will "listen" for this and check if the Dice Total matches its specific winning number to give you Coins.

Step 2: Visual City Building (Cloning)

The Goal: Make buildings appear on the screen when you buy them.

• The Building Sprite:
  • Create one sprite for every building (Wheat Field, Cafe, Mine, etc.).
• The Buying Logic:
  • Create "Buy" code for each building. When clicked, check: if Coins > Cost.
  • If successful, subtract the cost from Coins and Create a Clone.
• Cloning the Building:
  • Now update the code for When I Start as a Clone.
  • Inside that block, update the Payout to the value of what happens when the dice rolls that number.
  • Add a script: when I start as a clone, use go to x: (random) y: (random) to place the building in your city area.
• Check Payout
  • When I receive Check Payout, check to see if the Dice Roll equals the activation number.
  • Update the number of coins by the payout value.

Step 3: Strategic Synergies (Math Operators)

The Goal: Create advanced buildings that give bonuses based on other buildings you own.

• Tracking Collections: Create variables to track totals, such as Total Flower Gardens or Total Mines. Every time you buy one, change that variable by 1.
• The Synergy Logic:
  • For a building like the Flower Shop (which pays out based on how many gardens you have), use the Operator blocks.
  • When the dice hits the Flower Shop’s number, use: change Coins by (Total Flower Gardens * 3).
  • This rewards the player for planning their city layout instead of just buying random items.

Step 4: Level Progression & Resets

The Goal: Create a sense of achievement by unlocking new items and clearing the board for a new challenge.

• The Level Variable: Create a variable called Level.
• Unlocking Content:
  • On your "Buy" buttons, use an if block: if Level > 2 then show else hide.
  • This keeps the screen clean and introduces new buildings (like the Mine or Restaurant) only when the player is ready.
• The Level-Up Script:
  • Create a script that constantly checks: wait until Coins > Goal.
  • When the goal is hit, show a "Level Up!" message.
  • The Reset: To start the new level, set Coins to 5, set Roll Count to 0, and use broadcast Clear City.
  • All building clones should have a script: when I receive Clear City, delete this clone.

Step 5: Adding Visual "Juice"

The Goal: Use motion to show the player exactly when and where they are earning money.

• Flying Coins:
  • Create a small "Coin" sprite.
  • When a building clone triggers a payout, it should create clone of Coin.
• The Animation Script:
  • Inside the Coin clone: when I start as a clone.
  • go to [Building Sprite] (the one that just paid out).
  • show.
  • glide 0.5 secs to [Coin Counter Display].
  • delete this clone.
• Unlocking the Second Die:
  • At Level 3, show a new button: "Roll 2 Dice."
  • When clicked, change the math to: set Dice Total to ((pick random 1 to 6) + (pick random 1 to 6)). This allows the player to finally hit high-number buildings like the Mine (11 or 12).

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Summary of Logic

By the end of this project, you have mastered:

1. Events: Using broadcasts to coordinate between the dice, the shop, and the city.
2. Cloning: Managing dozens of visual objects without creating dozens of separate sprites.
3. Conditionals: Checking if a player has enough money or has reached the correct level to proceed.
4. Math Operators: Creating complex economic bonuses that make the game strategic.

Code a Mini Economy Town: A Development Guide

This guide breaks down the creation of Dice City Tycoon, a browser-based economic simulator. We developed this game in five distinct phases, moving from a simple text-based engine to a polished, multi-level city builder.

This page is all about building the game in HTML for a Web Browser. This is where I like to prototype my games before building a polished version in a game engine.

A Scratch Version of this Guide is available.

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Phase 1: The Core Engine (Randomized Income)

Objective: Establish the "Game Loop." We needed a way for the player to spend money (Input) and earn it back through luck (Output).

• How it was accomplished:
  • Data Structure: We used a JavaScript object (state) to track coins and buildings, and an array (buildingData) to define what each building does.
  • Randomness: We used Math.floor(Math.random() * 6) + 1 to simulate a 6-sided die.[1][2]
  • Logic: Every time the player rolls, the code loops through their buildings. If the roll matches a building's "trigger" number (e.g., a Wheat Field triggers on a 1), it adds coins to the total.

Phase 2: Visual Feedback (The Emoji City)

Objective: Make the game feel like a "City Builder" rather than just a spreadsheet. We wanted the player to see their progress physically.

• How it was accomplished:
  • The City Window: We created a dedicated CSS div (the "green field") using Flexbox.
  • Dynamic DOM Injection: In the buyBuilding function, we added a line that creates a new <span> containing an emoji (🌾, ☕, ⛏️) and appends it to the city window.
  • CSS Animations: We used a @keyframes "pop-in" effect to make buildings bounce into existence, giving a satisfying sense of "impact" when buying.

Phase 3: Strategic Depth (Synergy Buildings)

Objective: Move beyond simple payouts and introduce strategy. We wanted buildings that "talk" to each other.

• How it was accomplished:
  • Conditional Payouts: We added "Synergy Buildings" like the Flower Shop and Furniture Factory.
  • Dynamic Calculation: Instead of a flat payout number, we wrote a function that checks the current state. For example, the Flower Shop calculates: (Count of Shops) * (3 * Count of Flower Gardens).
  • Strategy Shift: This forced players to decide between "Reliable" income (Wheat Fields) or "High-Ceiling" combos (Flower Shop + Gardens).

Phase 4: The Progression System (Levels & Unlocks)

Objective: Prevent the player from being overwhelmed and create long-term goals.

• How it was accomplished:
  • Level Gatekeeping: We added a minLvl property to each building. The "Market" code was modified to only show buildings if game.level >= building.minLvl.
  • The Level-Up Trigger: After every roll, a checkLevel() function compares the player's coins to a target goal (e.g., Level 1 goal = 12 coins).
  • The "Second Die" Mechanic: We locked the ability to roll two dice until Level 4. This created a major gameplay milestone that felt like a reward for mastering the early game.

Phase 5: Polish & "Juice" (Animations & Resets)

Objective: Make the game feel professional and implement a "Prestige" loop where the game gets harder but more rewarding.

• How it was accomplished:
  • Coordinate Math: For the sliding coins, we used getBoundingClientRect(). This allowed JavaScript to find the exact pixel location of the dice and the pixel location of the coin counter on your screen.
  • Coin Flying: We created temporary "flying coin" elements and used CSS transitions to move them between those two coordinates.
  • The Great Reset: To keep the game challenging, we added a reset logic on level-up. When a goal is hit, the code clears the buildingsOwned object, empties the City Window HTML, and sets coins back to 5. This forces the player to use their newly unlocked buildings to reach the next, higher goal.

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Final Project Architecture Summary

1. HTML: Provides the skeleton (the city field and the control sidebar).
2. CSS: Handles the "Vibe" (grass colors, dirt borders, and button styling).
3. JavaScript: Acts as the brain, managing the level logic, coin math, and animations.

Key takeaway: By starting with a simple dice roll and layering on visuals, strategy, and then progression, you can build a complex simulation starting from just a few lines of code.

DOWNHILL SKIER GAME CODING CHALLENGE

The Challenge

Your mission is to create a downhill skiing game.
The skier stays near the top of the screen while the world moves toward them.

Goal:
Avoid obstacles for as long as possible.

This game uses a classic trick in game design:
If the environment moves, it feels like the player is moving.

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The Big Idea

Even though it looks like the skier is racing downhill:

• The skier only moves left and right
• The obstacles move upward toward the skier
• The player survives by dodging obstacles

Obstacles can include:

• Flags
• Rocks
• Trees

Play our html version of the game.

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Step 1: Create Your Skier (Player Sprite)

Start with your skier — this is your avatar.

Requirements:

• Place the skier near the top of the screen
• Allow the skier to move left and right

Tip #1: Player Movement

Think carefully about how the skier should move.

You might:

• Use the left and right arrow keys
• Make the skier move toward the mouse

There is no single correct solution — choose what feels best for your game.

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Step 2: Add Your First Obstacle

Obstacles create the challenge.

Start simple:

1. Create one obstacle
2. Spawn it at the bottom of the screen
3. Move it up the screen toward the skier
4. When it goes off screen, reset it to the bottom

Tip #2: One Obstacle First

Do not add everything at once.

• Get one obstacle working
• Make sure it moves correctly
• Then add more obstacle types

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Step 3: Create the Downhill Illusion

The skier does not move downhill — the obstacles do.

Obstacle Rules:

• Move at a constant speed
• Only move on the Y-axis
• No left or right movement

Tip #3: Keep the Physics Simple

Simple movement makes debugging easier.

• No X movement
• Only Y movement
• Smooth, steady speed

This keeps the focus on gameplay, not complex math.

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Step 4: The Game Loop

Every frame, your game should:

1. Move the skier left or right
2. Move obstacles upward
3. Check for collisions
4. Repeat

This loop continues until the skier hits an obstacle.

Check out our MakeCode Arcade Version of the Game!

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Game Over

When the skier touches an obstacle:

• End the game, or
• Display a Game Over message

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Extension Challenges (Optional)

Want to take your game further?

Try adding:

• A score based on time survived
• Faster obstacles over time
• Sound effects
• Multiple levels or difficulty modes

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Final Thought

Start small. Test often.
Every great game begins with something simple.

Happy coding.

Overview

Design a LEGO build that transforms from a desk into a bed, inspired by Sarah E. Goode’s folding cabinet bed. This challenge highlights how engineers solve real problems—like limited living space—by creating furniture that serves multiple purposes.

Watch the full build video: https://youtu.be/h9pIRXLIa8w

Best for: Grades 2–6
Kits: LEGO Spike Prime or Spike Essential
Time: 45–60 minutes

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Who Was Sarah E. Goode?

Sarah E. Goode was an inventor and furniture store owner who lived in the late 1800s. As cities grew, many families lived in very small apartments with limited space. Sarah noticed that people needed furniture that could do more than one job.

Her solution was a folding cabinet bed—a piece of furniture that could be used during the day and transformed into a bed at night. She became one of the first Black women to receive a U.S. patent.

Big idea: Good design makes life easier by solving everyday problems.

This image is an AI enhancement of the blurry photograph.

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Real Invention: Key Features

Sarah Goode’s folding cabinet bed needed to:

• Save space in small apartments
• Transform smoothly between uses
• Be strong and stable when used as a bed
• Fold away neatly during the day

This invention helped families live more comfortably in tight spaces.

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LEGO Robot Challenge

Your mission: Build and program a LEGO model that transforms from a desk into a bed using motion and structure.

Build Requirements

• A desk configuration and a bed configuration
• At least one hinge or pivot point
• One motor to assist with the transformation
• The transformation must be controlled and repeatable

Optional Add-Ons

• Add a button to switch between desk and bed modes
• Include supports or legs that lock into place
• Add a second transformation (bed → desk)
• Add sound or light when the transformation begins

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Suggested Materials

• 1 Motor
• LEGO beams, connectors, hinges, and plates
• Hub (Spike Prime or Spike Essential)

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Programming Concepts

• Motor direction and power
• Timers / wait blocks
• Sequences
• Loops

Extension: Use conditionals so the build only transforms when it is safe.

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Discussion Questions

• Why was space such a big problem in apartments?
• How does furniture that does multiple jobs help families?
• What could go wrong if the bed wasn’t stable?
• What other furniture could be redesigned to save space?

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Learning Objectives

Students will:

• Understand how constraints influence design
• Practice mechanical transformation and sequencing
• Explore structural stability
• Connect historical inventions to modern design

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Extensions & Challenges

• Design furniture for a tiny apartment
• Compare Sarah Goode’s invention to modern Murphy beds
• Test how much weight the bed can support
• Create a full transforming room

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Video Connection

🎥 Watch the full build video: https://youtu.be/h9pIRXLIa8w

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Part of the Black History LEGO Robotics Series

This build is part of our Black History LEGO Robotics Challenge—exploring inventors, engineers, and innovators through hands-on LEGO robotics.

What problem would you solve with transforming furniture?

Overview

Build a LEGO robot that opens and closes a door automatically—no hands required. This challenge is inspired by Alexander Miles, the inventor whose automatic elevator door system made buildings safer and helped shape modern cities.

Watch the full build video: https://youtu.be/CT-ELr0o-v0

Best for: Grades 2–6
Kits: LEGO Spike Prime or Spike Essential
Time: 45–60 minutes

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Who Was Alexander Miles?

Alexander Miles was an inventor who noticed a serious safety problem in the late 1800s: elevator doors were often left open by mistake, leading to dangerous accidents. After a close call himself, Miles designed an automatic elevator door system that opened and closed on its own. His invention reduced human error and made elevators much safer to use.

Big idea: Automation can protect people by removing dangerous human mistakes.

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Real Invention: Key Features

Alexander Miles’s automatic door system needed to:

• Open and close automatically
• Stay synchronized with elevator movement
• Prevent doors from being left open
• Operate smoothly and safely

These ideas are still used in modern elevators and automatic doors today.

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LEGO Robot Challenge

Your mission: Design and program a LEGO door that opens when someone approaches and closes automatically after a short delay.

Build Requirements

• 1 motor to move the door
• 1 sensor (distance or color) to detect presence
• Door opens without touching
• Door closes automatically

Optional Add-Ons

• Emergency stop button
• Sound or light indicator
• Adjustable open/close timing
• Two doors that open in opposite directions

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Suggested Materials

• 1 Motor
• 1 Distance Sensor (or Color Sensor)
• LEGO beams, connectors, and plates
• Hub (Spike Prime or Spike Essential)

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Programming Concepts

• Sensors as inputs
• Motor direction and power
• Timers / wait blocks
• Loops

Extension: Add conditionals so the door stays open while someone is detected.

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Discussion Questions

• Why were automatic doors safer than manual ones?
• What problems could happen if a door didn’t close?
• Where do you see automatic doors today?
• How does automation help people with mobility?

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Learning Objectives

Students will:

• Understand how automation improves safety
• Practice sensor-based programming
• Explore cause-and-effect logic
• Connect historical inventions to modern technology

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Extensions & Challenges

• Design an elevator system around the door
• Compare early elevators to modern smart elevators
• Test different sensor distances
• Create a building with multiple automatic doors

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Video Connection

🎥 Watch the full build video: https://youtu.be/CT-ELr0o-v0

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Part of the Black History LEGO Robotics Series

This build is part of our Black History LEGO Robotics Challenge—exploring inventors, engineers, and innovators through hands-on LEGO robotics.

What will you automate next?

Build a working LEGO traffic signal inspired by Garrett Morgan, the inventor whose improved traffic light design helped make roads safer. In this challenge, students design a motorized signal system, learn why timing and clear communication matter, and connect history to real engineering decisions.

Watch the Video! Click Here

Who Was Garrett Morgan?

Garrett Morgan was an inventor and entrepreneur who saw a dangerous problem on early 1900s streets—cars, horses, and pedestrians all competing for space. After witnessing a serious accident, he designed an improved traffic signal that warned drivers before it was time to stop. His ideas laid the foundation for modern traffic lights and saved countless lives.

Big idea: Engineering starts with noticing a problem and designing a safer solution.

Real Invention: Key Features

Morgan’s traffic signal needed to:

• Clearly tell people when to stop and go
• Include a warning phase before stopping
• Be simple and reliable so drivers could understand it quickly
• Improve safety at busy intersections

LEGO Robot Challenge

Your mission: Build a LEGO traffic signal that controls movement using timing and visual signals.

Build Requirements

• One motor to rotate or switch the signal
• Visual indicators (colors, panels, or arms)
• A programmed timing sequence (stop → warning → go)

Optional Add‑Ons

• Add a button to change modes
• Add a sound for the warning phase
• Create two directions of traffic

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Suggested Materials

• 1 Motor
• LEGO beams, connectors, and plates
• Light elements or colored bricks
• Hub (Spike Prime or Essential)

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Programming Concepts

• Timers / wait blocks
• Motor control
• Sequence order
• Loops

Extension: Add conditionals to handle pedestrian crossings.

Discussion Questions

• Why was a warning signal important?
• What could go wrong if the timing is too fast or too slow?
• How does this robot help keep people safe?
• What improvements would you make today?

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Learning Objectives

Students will:

• Understand how inventions solve real-world problems
• Practice sequencing and timing in code
• Explore how safety influences engineering design
• Connect history to modern technology

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Extensions & Challenges

• Design a pedestrian crossing button
• Add a second intersection
• Compare old traffic signals to modern smart traffic systems
• Track how many cars safely pass through

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Video Connection

🎥 Watch the full build video: https://youtu.be/o2VpeirX9PY

Read More About Garrett Morgan

After spending four years in Cincinnati, in 1895 Morgan moved to Cleveland, where he took a job sweeping floors at the Roots and McBride Co. Over time, he grew familiar with the company’s sewing machines, teaching himself how to operate and repair them. Not only did Morgan become a skilled machinist, but he also found inspiration for his first invention — a belt fastener for sewing machines.

In 1907, Morgan started his own business where he repaired and sold sewing machines. Two years later he opened a tailor shop: The Morgan Skirt Factory. While his wife Mary sewed clothes, Morgan built and maintained the sewing machines. He also began experimenting with a liquid for polishing sewing machine needles, preventing them from burning fabric as they sewed. When he discovered the liquid also could straighten hair, he used it to develop a hair cream, and he soon established the G. A. Morgan Hair Refining Co. Morgan then began investing his profits into developing more inventions.

Morgan found the motivation to develop one of his most impactful inventions when he learned about the devastating Triangle Shirtwaist Co. fire that caused the deaths of 146 garment workers in New York City in 1911. Understanding that the firefighters had struggled with smoke inhalation, Morgan began to devise a solution. In 1912, he filed for a patent on his breathing device, a “safety hood” that was designed to give a first responder the ability to “supply himself at will with fresh air from near the floor [and] at the same time forcibly remove smoke or injurious gases from the air tube.” Two years later, he established the National Safety Device Co.

In 1916, the importance of Morgan’s safety hood invention was demonstrated at the site of a tragic accident in Cleveland. Following an explosion at the Cleveland Waterworks that killed 18 workers, survivors were trapped as a gas-filled tunnel collapsed under Lake Erie. Without effective safety equipment, rescuers had been unable to reach them because smoke, dust and fumes blocked their way. But when some volunteers — including Morgan himself — put on safety hoods, they were able to successfully reach and rescue several survivors.

Despite his invention’s obvious lifesaving potential, Morgan found difficulty in selling his safety hood to white fire chiefs who refused to buy products from a Black inventor. In response, Morgan sought the advice of the famous entrepreneur J.P. Morgan, who suggested he remove his first name from the product. Following this advice, the inventor began calling his device the “Morgan Safety Hood.” He also hired white actors to promote the product at conventions, helping him to avoid racist objections. Morgan’s new marketing strategies worked, and fire departments across the country finally began to buy his early gas masks.

By the 1920s, Morgan had established himself as a successful businessman and had purchased an automobile. While driving through Cleveland one day, he witnessed a collision between a horse-drawn carriage and another vehicle at an intersection. This experience compelled Morgan to once again use his talents and skills to develop an invention that would improve the safety and welfare of his fellow citizens.

Building a Mars Rover with LEGO Robotics

A rover is an automated motor vehicle that propels itself across the surface of a celestial body. A rover may examine territory and interesting features, analyze weather conditions, or even test materials, such as soil and water.

What does it take to go to Mars?

People have long been fascinated by Mars, the planet in our solar system that’s most like Earth. Uncrewed missions have sent orbiters, probes, and rovers to explore the planet since the 1960s, but what would it take to carry out a successful human mission to Mars?

Mission Mars Unit Overview

In this unit, your students will work as scientists and engineers. They’ll immerse themselves in motivating STEM activities that prompt creative problem-solving, communication, and exploration.

Mission: Activate Communications

Mars Mission : Activate Communications - Sprattronics

Mission: Vent Bot

VENT Bot Maze Mission - Sprattronics

Mission: Ice Collection

Mars Mission : Ice Collection Challenge - Sprattronics

Mission: Rocket Launcher

Lesson Video

Step by Step Build Directions

Mission: Supply your Base

Download this as a PDF to use in class or at home!

Today you are an engineer! Your mission is to design and build a robot rabbit that can move in a rabbit-like way. We’ll use the Engineering Design Process:

Challenge → Brainstorm → Design → Create → Test → Improve → Share

Real-World Context: In Florida’s Everglades, invasive Burmese pythons hurt native wildlife. Engineers experiment with “robot rabbits” to lure and safely capture pythons so scientists can protect other animals.
Your goal: Build a rabbit-like robot that shows realistic motion (hopping, moving forward, or “being interesting” to a predator) and can keep moving without falling apart.

Challenge

Deep in the Florida Everglades, something unusual is hopping into action. It’s not a real rabbit—it’s a robot bunny! And this little machine has a big job: helping scientists fight one of the Everglades’ most dangerous invaders, the Burmese python.

Why Pythons Are a Big Problem

Burmese pythons are not supposed to live in Florida. They came to the U.S. as pets in the 1970s, but some were released into the wild. By the 1980s, they were living and breeding in the Everglades.

These snakes are huge—some grow over 18 feet long—and they eat almost anything they can catch. That includes raccoons, rabbits, opossums, bobcats, and even deer.

Scientists found that in parts of the Everglades, mammal populations have dropped by more than 90%. For example, marsh rabbits, a favorite python snack, have nearly disappeared. With so many animals gone, the entire ecosystem is out of balance.

Today, there may be tens of thousands of Burmese pythons in Florida, and they’re spreading farther north each year.

The Idea of Robot Rabbits

To stop the pythons, researchers at the University of Florida came up with a creative plan: build fake rabbits that trick the snakes.

These aren’t ordinary toys. Each robo-bunny is stuffed with special electronics:

• Motors to make it move and hop.
• Heaters to give it the same warm body temperature as a real rabbit.
• Cameras and sensors to alert scientists when a python comes close.
• Solar panels so they can recharge in the Florida sun.

From far away, they look just like marsh rabbits—the kind pythons love to eat.

When a python slithers near, the robot alerts the research team. The hope is that the snakes can then be caught before they eat more of Florida’s wildlife.

Why Not Use Real Rabbits?

Scientists tried that years ago. They placed live rabbits in pens, and pythons showed up almost every week. But caring for live animals across the huge Everglades was too difficult and not very kind to the rabbits.

The robo-bunnies solve that problem. They can survive in water, mud, and rain, and they don’t need food or care. Some researchers are even testing if adding rabbit scent will make the robots more convincing.

Other Ways Florida Fights Pythons

Robot rabbits aren’t the only strategy. Florida has tried many ways to reduce the python population, including:

• Hiring expert hunters, even bringing in snake catchers from India.
• Holding the Florida Python Challenge, a yearly event where hunters compete for cash prizes by capturing snakes.
• Paying full-time hunters who get bonuses for catching longer snakes. Since 2019, hunters have removed more than 15,000 pythons.

Even with these efforts, the snakes are still winning. That’s why scientists are excited to try bold ideas—like robo-bunnies.

Could Robo-Bunnies Save the Day?

The project is still in its early stages. Right now, scientists are testing 40 robo-bunnies in different areas of South Florida. If they work, they could help hunters find more pythons, faster, and bring back balance to the Everglades.

It may sound a little silly to fight giant snakes with toy rabbits. But sometimes, solving big problems requires small, creative solutions.

As one scientist put it: “After 10 years of studying the problem, you don’t just want to watch it happen—you want to do something.”

And maybe, just maybe, robo-bunnies are the heroes the Everglades have been waiting for.

Brainstorm

Come up with ideas on how to solve the problem.

List or sketch 3 different features that are important to include with our robot.

Parts or mechanisms we might try (check any):
☐ Legs with hinges ☐ Wheels as “feet” ☐ Cams/lifters ☐ Rubber band power
☐ Gear train ☐ Counterweights ☐ Tail/ears for balance

Design

Sketch out your robot plan. What parts do you think you will need to make your rabbit a reality?

Create

Build your robot using the materials you have. You can build a robot rabbit using a LEGO Spike Essential Kit, a LEGO Spike Prime Kit, or just LEGOs you have with you.

Build checklist:
☐ Frame is sturdy
☐ Moving parts don’t jam
☐ Battery/motor (if used) is secured
☐ Nothing sharp or loose

Test

Try out your LEGO Robot to see if it works.

Mark a start line and a goal line. Clear the path.

Run your trials and record results:

Trial	Went Straight? (Y/N)	Distance (cm)	Stayed Together? (Y/N)	Notes
1
2
3

Did it meet your success criteria?
☐ Yes  ☐ Not yet

Improve

Make changes to make your robot rabbit work better.

What didn’t work the way we wanted?

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Change we will try:

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Why we think it will help:

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Re-test results (pick one):
☐ Better ☐ Same ☐ Worse

Our robot did not hop correctly. We changed our code to make it hop in a more bunny-like manner. Another problem we faced was that the snakes hunt by temperature and scent detection. Adding a "Hot Hands" and some rabbit spray to our bot, it made the snake more likely to approach.

Share

Name of our robot rabbit: _______________________________________

How it works (in one or two sentences):

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What we’re proud of: _____________________________________________

What we would try next time: ______________________________________

Share your robot in the comments on our YouTube page!

Reflection (Optional)

One thing I learned about engineering: ______________________________

One thing I learned about invasive species: __________________________

A new idea I want to try: __________________________________________

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Quick Checklist

☐ I completed all 7 steps
☐ I tested at least 3 times
☐ I improved my design
☐ I can explain how my robot works

Want to make your LEGO Spike Prime robot turn perfectly every time? Whether you're preparing for FIRST LEGO League or just want to build better bots, this step-by-step guide will help you fine-tune your robot’s turning using real data and the built-in Yaw sensor.

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🔍 What You’ll Learn

• What a Yaw sensor is and how it works
• How to apply the Scientific Method to robot programming
• Why robots overshoot turn angles at higher power levels
• How to calculate and apply a correction offset
• How to build smarter, more reliable turning code using My Blocks

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🎥 Watch the Full Tutorial

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🧭 What Is Yaw and Why Does It Matter?

Yaw measures your robot's rotation around the vertical axis—basically, how much it's turned left or right. The LEGO Spike Prime Hub tracks yaw from -180° to 179°, making it perfect for turn-based navigation.

But there's a catch: as motor power increases, so does inertia—which means your robot often overshoots the desired angle.

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🔬 The Scientific Method for Better Turns

Here’s how we used the Scientific Method:

1. Ask a Question: Why does our robot overshoot 90° turns at higher power?
2. Form a Hypothesis: Higher power = more overshoot.
3. Conduct an Experiment:
   • Turn to 90° using different power levels (20%, 30%, 40%, 50%)
   • Run 5+ trials at each level
   • Record the actual stopping angle
4. Analyze Results:
   • Calculate average overshoot
   • Determine offset needed for accuracy
5. Apply & Test:
   • Modify your code to stop before the target angle
   • Improve My Block logic to factor in speed-based offset

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📊 Example Data Table

Power %	Target Angle	Actual Avg. Angle	Offset Required
20%	90°	92°	-2°
40%	90°	97°	-7°
50%	90°	100°	-10°

Use this data to adjust your wait-until yaw angle block by subtracting the correct offset.

This is the code we will be modifying for the experiment.

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🧱 Build a Smarter My Block

Create a custom My Block called YawTurn. It should:

• Take input: angle,
• Reset yaw
• Estimate the offset based on power
• Subtract offset from target angle
• Wait until yaw = corrected angle

This makes your robot modular, reusable, and competition-ready.

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✅ Why This Works for FLL and Classroom Robots

By controlling your turns with this method:

• You’ll score higher in the Robot Game
• Your robot will navigate missions with confidence
• You’ll teach students real scientific inquiry through robotics

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📥 Get the Lesson PDF + Sample Code

Download:

• [✅ PDF Lesson Plan for Educators ]
• [🔗 Spike Prime Leson on MyBlocks]

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🔑 Learning Targets

• How to improve LEGO Spike Prime robot turns
• LEGO Spike Prime turn accuracy
• Use yaw sensor LEGO robot
• FLL robot turn programming
• Yaw offset LEGO robotics

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💬 Leave a Comment or Question

Have questions about your robot's turns? Drop them in the YouTube comments or email us directly!

About Preston Spratt your Robotics Instructor

Preston Spratt started Sprattronics to provide children with incredible learning opportunities. As a school principal, he has specialized in bringing project-based learning into schools. Sprattronics is a place for children to learn about the things that interest them and solve problems that excite them.

Parents should have a choice of what their children are learning, and that it can happen in a safe and welcoming environment. At Sprattronics, Greenville, South Carolina, we focus on children making discoveries and encourage them to explore the things that interest them.

This blog post is available in video format on YouTube.

Introduction

If you’re a DJI drone operator, you may have noticed a major change recently. Just days after we released a video on how to geo-unlock your DJI drone, DJI announced that they’ve lifted geofencing restrictions across the United States. This is a significant shift aimed at aligning their systems more closely with FAA guidelines and ensuring that responsibility for compliance falls squarely on the pilot.

So, what does this mean for drone enthusiasts? Essentially, DJI drones now allow you to take off and fly almost anywhere, within technical limitations. However, this newfound freedom doesn’t absolve you of responsibility—you’ll still face the consequences if you break FAA regulations.

In this post, we’ll cover:

1. What the change to DJI’s maps looks like.
2. How to ensure you’re still flying legally and responsibly.
3. Real-world examples of what happens when drone pilots push the boundaries and get into trouble with the FAA.

Let’s dive in.

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How the Maps Have Changed

Until January 13, 2025, DJI’s maps were layered with multiple types of flight restrictions. For example, a single location—like your local park—might fall into multiple restricted zones, including:

• Authorization Zones: These appeared in blue and required pilots to unlock them using a verified DJI account.
• Altitude Zones: Gray areas on the map where flight height was limited, such as near airports.
• Warning Zones: These zones triggered warnings in the DJI app but didn’t necessarily prevent flights.
• Enhanced Warning Zones: These zones required users to unlock them in-app but didn’t need a verified account or internet connection.
• Restricted Zones: These red zones completely prohibited flight unless special permission was granted by DJI through an online unlocking request.

For instance, at my local park, I used to deal with an authorization zone, a 196-ft altitude limit zone, an enhanced warning zone, and a general warning zone. We had to get LAANC approval to fly and submit a DJO Geo Unlock request just take off in an area where the FAA says we can fly up to 400 feet.

Now, with geofencing removed, DJI no longer enforces these zones, meaning your drone will no longer prevent you from taking off or flying through these areas. Instead, it’s now entirely your responsibility to comply with FAA airspace rules.

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How to Load the New Maps on DJI Fly

Update the DJI FlySafe Database

Make sure your drone and app are running the latest firmware and database updates. This will ensure the map reflects the new geofencing changes.

You can do this by clicking PROFILE --> Settings --> Check for FlySafe Database Updates

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Use FAA Approved Apps

We love AutoPylot. It is B4UFly approved, has up-to-date FAA maps and restrictions, and allows for instant LAANC approvals.

Five Ways to Get in Trouble with the FAA

While the removal of DJI’s geofencing simplifies flying, it’s crucial to stay within FAA regulations. Here are five ways to land yourself in hot water:

1. Flying in Restricted Airspace

Just because DJI won’t stop you doesn’t mean you can ignore airspace restrictions. Flying near airports, military bases, or in prohibited zones without prior FAA authorization can result in hefty fines.

2. Flying Without the Correct Certification

If you’re flying recreationally, you need to pass the TRUST test (The Recreational UAS Safety Test). For commercial use, you must hold a Part 107 Remote Pilot Certificate. Operating without the appropriate credentials can lead to penalties.

3. Flying Over People

FAA rules prohibit flying drones directly over people unless specific waivers or safety conditions are met. This is especially critical in populated areas or events.

4. Not Yielding to Manned Aircraft

Drones must always give way to manned aircraft. Failing to yield to planes, helicopters, or emergency response aircraft could result in severe penalties and risks to safety.

5. Flying Above 400 Feet

The FAA’s maximum altitude for drones is 400 feet above ground level (AGL) in most areas. Exceeding this limit can interfere with manned aviation and result in fines or other legal action.

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Final Thoughts

The removal of DJI’s geofencing system represents a shift in responsibility from the drone manufacturer to the pilot. While this change offers greater freedom, it also means that you must be diligent about understanding and following FAA regulations.

Before taking off, make sure you:

• Use apps like AutoPylot to check for airspace restrictions.
• Stay under 400 feet.
• Avoid flying over people or in restricted areas.
• Keep your certifications up to date.

Flying a drone can be an incredible hobby or a valuable tool for commercial work—but with great power comes great responsibility. By following the rules and respecting airspace, you can ensure your flights are safe, legal, and trouble-free.