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Week 18: Applications & Implications

Plan a final project Overview

This proposal outlines a comprehensive final project that integrates various units of study. The project will be designed to demonstrate mastery of multiple skills, including 2D and 3D design, fabrication processes, electronics design and production, and system integration.

Project Objectives:

What will it do?

Mixed Perler beads are poured into a funnel. A vibrating motor (optional) helps them feed onto a rotating disc (or a disc with small pockets). The disc rotates continuously, bringing beads one‑by‑one over a fixed RGB color sensor. After color identification, a second motor rotates a sliding track / curved ramp to align with the correct bin, and the bead rolls down into it. An optional base switch (limit switch) detects when a bin is full.

Who has done what beforehand?

What sources will you use?

I will use the following sources to complete my final project:

What sources will be used?

  • Color sensing: TCS34725 RGB sensor (Arduino library, I²C).
  • Motor control: Stepper or DC motors with driver (DC 28BYJ-48 or SG90).
  • XIAO ESP32-C3: Official documentation, pinout, PWM, and interrupt handling.
  • Mechanical design: Fusion 360 for disc, curved ramp, and sliding track; laser-cut acrylic for chassis.
  • Vibration motor: Simple DC0612 motor.

Design process demonstration

Design Item Tool Process Demonstrated
Funnel + rotating disc + pockets Fusion 360 3D design (additive)
Curved ramp + rotating sliding track Fusion 360 3D design (additive)
Chassis (base, motor mounts, bin holders) Laser maker 2D design (subtractive)
Custom PCB (breakout for motors, sensor, ESP32) KiCad /Easy EAD Electronics design
Firmware (color detection → track positioning) ESP32-C3 Embedded programming
Full assembly (disc + ramp + bins) Physical integration System integration

Where will they come from? And how much will they cost?

The color sensor, motors, and ESP32-C3 will be purchased from Taobao online stores. Laser-cut acrylic or wood will come from our school Keytech lab. The total cost would be around ¥70

Component Source & estimated cost
XIAO ESP32-C3 Taobao, ≈ ¥30
TCS34725 color sensor module Taobao, ≈ ¥15
SG90 micro servo Taobao, ≈ ¥10
Vibration motor (optional) Taobao, ≈ ¥5
PLA filament (3D-printed parts) Office own stock, ≈ ¥10
Laser-cut acrylic/wood (chassis) School lab, included in lab materials

What processes will be used?

Process Application
2D design Laser-cut acrylic base, motor mounting plates, bin holders
3D design Funnel, disc, curved ramp, sliding track
Additive fabrication 3D printing all plastic moving parts
Subtractive fabrication Laser cutting the chassis frame
Electronics design Custom PCB to connect XIAO, sensor, two motors, vibration, limit switch
Electronics production Milling PCB on Roland SRM-20
Embedded programming XIAO ESP32-C3: color reading, motor (stepper/servo) control, vibration PWM
System integration Mount disc axis, align sensor above disc, couple sliding track to servo

What questions need to be answered?

  • How fast can the rotating disc present beads without jamming the sensor?
  • What angle of the curved ramp ensures beads roll reliably into the sliding track?
  • Can one servo rotate the sliding track fast enough for 1–2 beads/second?
  • Does the vibration motor improve bead feed consistency, or cause beads to jump off the disc?
  • How to calibrate TCS34725 for the specific 3–4 Perler colors under ambient light?

What parts and systems will be made?

  • Self-designed and produced: 3D-printed funnel, rotating disc (with pockets or friction pads), curved ramp, rotating sliding track; laser-cut chassis; firmware.
  • Assembled from modules: RGB sensor (I²C), motor drivers, vibration motor, limit switch.
  • Integrated system: Funnel → vibrating feed → rotating disc → color sensor → rotating track → bins.

How will it be evaluated?

  • Step 1: Calibration

    Train the TCS34725 RGB sensor with 5 beads of each color (red, blue, yellow, green, orange). Store min/max RGB ranges.

    Set servo angles for each bin (0°, 45°, 90°, 135°, 180° for 5 bins).

  • Step 2: Accuracy test

    Prepare a mixed batch of exactly 50 beads: 10 of each of 5 colors.

    Pour into funnel. Run machine until empty.

    Manually inspect each bin. Count correct vs. incorrect.

    Formula: Accuracy = (correct beads in correct bin) / (total beads) × 100%

  • Step 3: Throughput test

    Run the same 50 beads. Use a stopwatch from the moment the first bead leaves the funnel to the last bead entering a bin. Repeat 3 times and average.

Summary slide for the final project

Video clip

Link in the final presentation schedule

Add slide link, video embed, and presentation schedule URL when ready.