WALL-E — UTRAHacks 2025 Winner 🏆

An autonomous robot car that conquered the maze, grabbed the flag, and found the center.

🚀 Inspiration

Sisyphus — but with motors and a flag instead of a boulder.

🤖 What It Does

TweakerBot autonomously navigates a maze and performs the following tasks:

• Grabs and releases a flag using a 3D-printed clamp actuated by a servo motor.
  
• Detects tile color using a bottom-facing color sensor to follow navigation cues.
  
• Avoids collisions by using a front-facing ultrasonic (echo) sensor to detect distances to walls.

🛠️ How We Built It

• Developed using the Arduino IDE and standard C++ libraries.
  
• Integrated sensors and actuators: color sensor, ultrasonic sensor, servo, and DC motors.
  
• All electronics powered by 9V batteries with a motor driver (L298N) handling control.

🧩 Challenges We Faced

• Lack of in-place turning from broken motor driver: Due to motor limitations, we couldn't pivot. We improvised by “jitter-turning” step-by-step.
  
• 3D-printed joints were unstable: Reinforced with strategic tape to hold parts in place.
  
• Battery voltage drop: Performance declined mid-run—fixed by sourcing extra batteries.
  
• Sensor overheating: Color and echo sensors shorted—resistors prevented thermal issues.
  
• Incorrect color readings: Faulty readings due to miswired pins—corrected during debugging.
  
• Center-finding geometry and lack of encoder: Complex especially due to lack of precise turning. We developed a novel strategy called the:

🔁 The "Secant Method" (Our Own!)

1. Enter the circle and track exit time.
   
2. Move halfway backward based on timing.
   
3. Rotate 90° right.
   
4. Re-locate circle edge.
   
5. Backtrack to approximate circle center.
   (See diagram — available upon request!)

🏅 Accomplishments We're Proud Of

• Built an autonomous, sensor-integrated robot in under 24 hours.
  
• Worked through countless hardware and geometry issues with tenacity and creativity.
  
• Developed and validated our own center-finding algorithm under uncertainty.
  
• First place at UTRAHacks 2025 🎉

📚 What We Learned

• Hardware always fights back—but iteration wins.
  
• Debugging sensors and building mechanical-electrical synergy taught us practical engineering.
  
• Success isn't just elegant code or precision builds—it's about working with what you have.

🔮 What's Next for TweakerBot

• Solve Challenge 3, which remains unconquered.
  
• Upgrade motor control to enable on-the-spot turning, enabling more precise algorithms.
  
• Explore more robust mechanical assemblies (less tape next time 😅).
  
• Optimize the Secant Method or replace it with something truly geometric.

Built With

• arduino