No matter what the size or shape of an LED, it brings out the curiosity in every hardware nerd, and is the lifeblood of badge life around the planet. Then there is the LED cube that takes LEDs to all sides — literally. [Tomverbeure] had his own adventure of creating an LED Cube by piecing together Pixel Purses and a Cisco3G Modem.
A quick search for Pixel Purse on the internet reveals a toy lady’s handbag with an LED matrix embedded in one side. [tomverbeure] tore down 12 of these so as to get two panels for each side of his creation. After a little bit of experimenting with PCB corner brackets, he finally got it right and he is able to merge the pieces together to form the cube.
Next comes the brain and the elected device An FPGA from an HWIC-3G-CDMA modem. Cisco routers have extension slots and the HWIC connector on this particular piece had usable GPIOs that connect directly to the Altera FPGA. Inside the FPGA, a RISC-V soft CPU is used to generate images that get processed and dispatched in a hardware block. [Tomverbeure] does a detailed explanation of the implementation for all the blocks which were written in SpinalHDL. The video below shows the project in action.