Mechanical, Optical, & Electronic Puzzle Cube
I made a puzzle cube for my wonderful electronics lab instructor who is also a professional trumpet player! A lot of the fun in making this was designing my circuits and mechanical components around 5 milled PCBs soldered together into a cube. Puzzles involve "playing" a sequence of notes on a flex PCB capacitive trumpet and using a butterfly flexure to align a laser path through a beamsplitter.
From left to right, the sides of the cube include:
- WS2812b LEDs
- resistor combinations with pads for probing
- laser diode regulated by a LM317 circuit and switched on/off electronically with a 2N7002 MOSFET
- QTPy ESP32 microcontroller
Sides 1 & 4 also include a photoresistor to detect laser beam alignment.
And the bottom:
- 5V power jack, switches for the board power and laser power, mount for butterfly flexure
I really wanted an excuse to fab a flexPCB, so I did so here. FlexPCB files are located in the trumpet subfolder.
The connector end of the trumpet was designed to fit in a 6pin/1mm FPC connector. I ended up just soldering it directly to the board though, since I ended up finding an end mill small enough to carve out the 1mm pitch pads. It also helped me avoid buying an extra component.
Watch a video demo of the cube being solved here :D