What do you get when you take 8,192 CH570 MCUs, put them on custom PCBs, and write firmware for this interconnected gaggle of cores? In the case of [bitluni]’s project, you get something that’s decidedly cluster-shaped.
These cheap MCUs feature a QingKe 32-bit RISC-V core that’s clocked at a maximum of 100 MHz, with an RV32IMBC instruction set. This means that they support integers, integer multiplication and division, bit manipulation, and compressed instructions, but no atomic, vector, or floating-point instructions.
The basic concept was to use a single MCU per pixel, but once you start scaling up a measly 10 mA and ~$0.10 per MCU to literally tens of thousands of them, you’re suddenly talking about thousands of dollars in hardware as well as a cool 655.36A at 3.3V – or 2 kW – for something close to QVGA resolution at 320×200. Clearly this would be a rather crazy project to implement, which is why each MCU also got its own RGB LED to immediately create the pixel.
In order to fit so many MCUs, the design was split across multiple PCBs, or blades, connected to a backplane. On each blade, a group of MCUs is connected to a controller MCU, in the form of a larger MCU. With some prototype blades assembled and bodges implemented, each single MCU could then be programmed.
