June 24, 2025

🌻 Flower Robot Challenge: Seek the Sun!

🚀 Your Challenge:

Can you build a LEGO robot that acts like a real flower?
Your robot should spin slowly to look for light, then stop when it finds the sun (or anything yellow)!


🌱 What Do Real Flowers Do?

Have you ever noticed how sunflowers turn to face the sun? That’s not just for fun—it’s a real plant behavior called phototropism.

🌞 Phototropism means:

Plants grow or move in response to light.

  • 🌻 Sunflowers face east in the morning and follow the sun during the day.
  • 🌿 The top of the plant grows faster on the shady side, which makes it bend toward light.
  • 💡 Plants need light to make food through a process called photosynthesis.

💬 Fun Fact:

Some flowers stop turning once they’re grown, but younger ones still move every day!


🔧 Robot Build Instructions

You’ll build a flower that:

  • Spins using a motor
  • Looks like a flower using bricks and petals
  • Stops when the color sensor sees yellow or a bright light

🛠️ Step 1: Build the Spinning Base

Build a sturdy base and mount a motor horizontally so it can spin a platform.
Make sure the whole thing doesn’t tip over when spinning!

We used the Twirling Teacups lesson as an introduction to a spinning base.


🪴 Step 2: Make the Stem

Use LEGO beams to make a vertical stem that connects your flower head to the spinning platform.


🌸 Step 3: Create the Flower

Your color sensor becomes the center of the flower.
Decorate it with bright petals—but make sure it can still “see” colors in front of it!


💻 Coding the Robot

Use this basic idea for your code:

forever:
Spin slowly
If color sensor sees yellow or a bright light:
Stop spinning

📹 Watch the example video for how this works:
Watch on YouTube

💡 Tip: You can use "wait until color sensor sees yellow" in your program, or detect brightness using the reflected light sensor mode.


🧪 Test Your Robot

Try these tests:

  • Shine a flashlight near the sensor. Does it stop?
  • Place a yellow object in front of it. Does it freeze?
  • Does it keep spinning if there’s no light or yellow?
  • Can you make it spin again after it stops?

🎨 Bonus Challenges

  • Decorate your flower with more petals, leaves, or a bug friend!
  • Make it change colors using lights when it stops.
  • Build a garden of robots and see how they all behave together!

📓 Record Your Learning

Use these questions in your science notebook:

QuestionYour Answer
What is phototropism?
How does your robot behave like a real flower?
What does the sensor do in your robot?
What did you change during testing?
What would you do differently next time?

🌼 Share Your Build!

Take a photo or video of your robot in action and share it with your class or post with permission!

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