Week 17 — Applications and Implications, Project Development
Final Project Question and Answer
What will it do?
Bandbox is an interactive music toy featuring four characters. When a button is pressed, the corresponding character lights up with an LED, performs a motion via a servo motor, and plays a unique melody using passive buzzers. Multiple buttons can be pressed simultaneously, allowing for polyphonic musical compositions. It offers both educational and entertaining experiences.
Who’s done what beforehand?
The project was inspired by digital music tools like Incredibox. While similar concepts exist in digital or basic toy forms, the combination of physical interaction, character-specific outputs, and melody layering in a self-contained system is original. Existing music box projects were researched for technical validation.
What will you design?
The entire design was custom-made: 3D printed case, laser-cut top panel, PCB layout (minimal headers only), button and LED placement, melody logic, and servo motion. Aesthetics and user experience were carefully balanced during the design process.
What materials and components were used?
- PLA filament (3D printed body)
- 5mm clear acrylic (laser cut panel)
- 4x momentary push buttons
- 4x LEDs
- 4x servo motors
- 13x passive buzzers
- 1x Raspberry Pi Pico W
- Custom PCB with headers
Where did they come from?
PLA and acrylic were sourced from local suppliers. Electronics were purchased through TME, DFRobot, and PCBWay. PCB production was done using local fab lab resources.
How much will they cost?
The total estimated cost is around $86 USD, including components, materials, and prototyping efforts.
What parts and systems were made?
- Custom 3D printed enclosure
- Laser-cut acrylic top panel
- Custom PCB with header pins
- MicroPython-based melody and interaction code
- Manual wiring and full assembly
What processes will be used?
- 3D printing (PLA)
- Laser cutting (acrylic)
- PCB milling or fabrication
- Embedded programming with MicroPython
- Manual soldering and mechanical assembly
What questions were answered?
- How to make physical music toys interactive and modular?
- How to drive servos and buzzers effectively with Raspberry Pi Pico?
- How to create a clean and compact electronic enclosure?
How will it be evaluated?
Evaluation criteria will include functional interactivity, polyphonic capability, physical design quality, clean assembly, and software performance. A demo video and live interaction will emphasize the user experience.
What tasks have been completed?
- 3D printing of the enclosure
- PCB production and basic assembly
- All servo and LED connections
- Melody programming and testing
What tasks remain?
- Final testing and debugging
- Filming of the presentation video
- Finalizing GitLab documentation
What has worked? What has not worked?
Servo control and melody playback worked better than expected. Some minor cable management issues and acrylic panel mounting required revision.
What will happen when?
When a button is pressed, the corresponding character’s LED turns on, the servo performs a repetitive motion, and a unique melody is played. Multiple buttons can be held for combined output.
What have you learned?
- Efficient use of Raspberry Pi Pico with servos and buzzers
- Programming melodies using MicroPython timing
- Balancing aesthetics and functionality in physical products
- How small design details can significantly impact the final product
Bill of Materials (BOM)
Electronics BOM
| Quantity | Component | Description | Unit Cost (USD) | Total Cost | Product Link |
|---|---|---|---|---|---|
| 1 | Raspberry Pi Pico W | Microcontroller with Wi-Fi | $6.00 | $6.00 | Link |
| 4 | Push Buttons (Momentary) | For user interaction | $0.30 | $1.20 | Link |
| 4 | LEDs (10mm) | Yellow visual feedback | $0.10 | $0.40 | Link |
| 13 | 5V Passive Buzzers | Melody playback | $0.50 | $6.50 | Link |
| 1 | Custom PCB | Header-only board | $5.00 | $5.00 | Link |
| – | Wires & Headers | Wiring and connectors | ~$5.00 | ~$5.00 | Link |
Structural BOM
| Quantity | Component | Description | Unit Cost (USD) | Total Cost | Product Link |
|---|---|---|---|---|---|
| 1 | PLA Filament | 1kg, 1.75mm | $25.00 | $25.00 | Link |
| 1 | 5mm Acrylic Sheet | Laser-cut clear panel | $10.00 | $10.00 | Link |
| – | Brass Inserts + Screws (M3) | Assembly hardware | ~$5.00 | ~$5.00 | Link |
| – | 5V Power Adapter | External power for servos | ~$10.00 | ~$10.00 | Link |