FIRST LOOK: Matthias Balwierz, a hardware hacker better known as Bitluni, is building a home-made GPU out of thousands of low-cost microcontrollers. Instead of relying on a single powerful processor, Balwierz spreads the work across thousands of RISC-V chips. Each one acts as both a processor and a pixel, thanks to an RGB LED soldered directly onto it. The result is a system where the graphics hardware and display are built into the same array of chips.
A Full HD display would need more than two million chips. So Balwierz scaled the concept down to a 320 x 200 resolution, a format that will still require 64,000 microcontrollers when complete. The current prototype is smaller, built with 8,192 chips arranged across custom circuit boards.
Each board handles a 16 x 32 block of pixels, and the boards themselves are arranged in a circular layout, loosely inspired by the Cray-1 supercomputer. The visual result is a dense array of blinking LEDs, each tied to its own processor.
The decision to attach a basic RGB LED directly to each chip came down to cost. More advanced addressable LEDs would have pushed the project budget too high.
The chips at the center of the build are QingKe CH570 microcontrollers. They cost about $0.13 each and include quite a bit of hardware for the price. Each one packs a 32-bit RISC-V CPU running up to 100 MHz, along with a USB controller, a 2.4 GHz transceiver, and Bluetooth 5.0 LE support.
