My Final Project¶
Please see bottom of the page for the AI acknowledgements
Connectors play important backbone of many Hardware products; linking the flow of electric power and data signals between different system components. We don’t always notice them, but their performance can often break or make a product’s reliability, safety and experience.
While designing my original Final Project (which I decided to work on privately, and hopefully eventually commercialise), I discovered that a well-designed connector will be a critical missing piece for achieving my vision.
This is my alternative Final Project, a tester device for discovering killer connector designs!
What does it enable?¶
Easily attach your original sockets to the shelf, and test them for their connectivity and User Experience.
- A Wooden Shelf: on which different socket pieces can be attached (up to 12 sockets). It offers choice of 2 directions; sideways and downwards.
- An Example Attachable Socket: a standard Type-A USB-mounted socket piece, and a respective connector (which houses a mystery circuit inside)
- Small Socket PCB: Housing the required circuit, in order to easily connect attachable sockets to main board.
- Main Board (Xiao MD24): 16 Analog Input pins, 4-Pin I2C bus socket (which enables the shelf to be scaled), and a 3-Pin Programmable LED socket (to signal successful connection).
The links will take you to the respective documentations on “Final Project Development” page.
BOM (Bill of Materials)¶
The total cost came down to 2,785 JPY, excluding machine costs.
| Part | Materials Used | Source | Price paid (JPY) |
|---|---|---|---|
| Shelf | 3 x 3mm MDF | Daiso | 300 |
| 1 x 5mm MDF | Daiso | 200 | |
| Wire rack | Daiso | 100 | |
| Attachable Boards | ABS Filaments for 3D printing | TIB | - |
| 4 x 10mm long Pin Sockets | Akizuki | 40 | |
| 1 x L-shaped Pin socket | Akizuki | 15 | |
| 4 x 10kΩ Carbon Resistors | Sengoku | 60 | |
| Main PCB Board | 1 x Seed Xiao MD24 | Sengoku | 1400 |
| 1 x FR-1 Copper-clad laminated substrate | FabLab Kamakura | 350 | |
| Pin Headers | TIB | - | |
| Attachable Socket | MDF (same as Shelf) | Daiso | - |
| Type-A USB socket | Sengoku | 150 | |
| 1 x Programmable LED (OST4ML8132A) | Akizuki | 20 | |
| Example Connector | Type-A USB connector | Sengoku | 150 |
| Others | Wires | Stock | - |
| TOTAL | 2,785 |
The biggest expense was 6 hours of Milling machine at FabLab Kamakura (25,000 JPY)😱
How was it evaluated? What worked? What didn’t?¶
How easy it is to set up different connections (Time taken to assemble a new connection)
- This device does make it significantly easier to set up new connectors and test them, compared to doing it all from scratch.
- Improvements around wiring, such as making use of QI connectors and labelling could go a long way to making it even more simple.
Modularity (Versatility of different connections it can accommodate)
- Can test connections from 2 directions with 1 device.
- Can also adjust the number of connectors and distance between each connectors.
- If I had more time, I would also liked to have the option of connecting upwards.
- I would also like to upgrade the code so the system is scalable.
Durability (Relatively portable, won’t break after repeated use)
- Thanks to interlocking joinery (although I forgot to document this) and the base, the shelf is quite secure, so it should be able to withstand many testing. It also didn’t dismantle when I travelled around with it.
- Didn’t have time to implement Protective measures around the circuit from voltage spikes and reverse current, etc that may occur during plugging in and out.
- Also didn’t have time to complete the protective housing around the PCB.
Not expensive or time-consuming to build
- Manged to keep the final cost of Material/components reasonable, although I’m sure I used more than double the amount during prototyping.
- Ended up not using half of the PDB boards I milled, which could have cut the machine cost by more than 10,000 JPY.
What are the implications?¶
This device will help me greatly in designing and perfecting an ideal connector for my ongoing Product development; a connector that is fail-proof, enjoyable to use, and not expensive to manufacture.
It would also be great if this simple hardware can be a means of crowdsourcing a range of other interesting connector designs.
Licensing¶
Midori’s Mystery Tester © 2025 by Midori Kurokawa
is licensed under CC BY-NC-SA 4.0
Files¶
- Shelf: Main / Base
- Connector: Socket / Connector / Tiny Socket PCB
- PCB Layout
AI Usage¶
The comic used on the Slide was generated with Google’s Gemini.
The opening video was a combination of 2 AI-generated videos; 1. OpenAI’s Sora2 on MindVideo (Text to video), and 2. Filmora Wondershare’s ReelBot (Image and text to video).
All were generated using the below prompt, which was co-written by me and Gemini;
First scene; a stealthy ninja infiltrates a futuristic robotics R&D company building as if in a spy action film.
Second scene: The ninja finds a lab room filled with robotic arms and advanced machinery, and an Asian female engineer with glasses is working on a small equipment. He crouches in the shadows from the corridor outside, observing through binoculars.
Third scene: As the ninja silently observes, the engineer suddenly senses she is being watched, and in a moment of realization, hastily moves to close the blinds, attempting to block the ninja’s view. The blinds are fully closed, and the Ninja mutters, “Is the world ready for this?” (later replaced with voice excerpt; “She’s onto something”).
The music was replaced with: Tense by YevhenAstafiev, on pixabay and Inspire2 by Wavecont, from chosic.com (Creative Commons CC BY-SA 4.0).