Mini Arduino Traffic Light – Snap-Fit 3D

Mini Arduino Traffic Light – Snap-Fit 3D Model for STEM Projects 🚦

Overview
A compact, press-fit traffic-light shell for Arduino demos and STEM lessons. Print, drop in three LEDs, and run the sample sketch.
90 second build • 3D Printed Arduino Traffic Light - YouTube

▶ Full source, code & wiring on GitHub

What’s in the STL pack?

Bill of Materials

• Arduino Uno / Nano
• 3 × 5 mm LEDs (R, Y, G)
• 3 × 220 Ω resistors
• Jumper wires
• 3D-printed parts (choose either the single-plate STL or the 5 loose parts)

(Wiring diagram and firmware are on GitHub.)

Print Settings (tested on Bambu Lab A1)

Assembly

1. Print the parts you prefer (single plate or individual STLs).
2. Press-fit LEDs into the front panel from inside.
3. Slide the panel into body.stl, then clip on rear_cover.stl.
4. Route wires down the pole and plug into the breadboard next to the stand.
5. Upload traffic_light.ino and watch the red → yellow → green loop!