[mrheosuper]

i was thinking of using FPGA to control led matrix, the algorithm is not hard, it's just there are too many pin to control, they need high clock rate if you want high color depth, a using MCU bit bang is not really a choice.

[RicoElectrico]

And Colorlight i5/9 boards are made for that very application; it just so happens they're a reasonable minimal devboards for ECP5 FPGAs. I don't think right now you can get anything more capable for the price (Yeah, there are super cheap decommissioned miners with Zynq, but there's almost no I/O fanned out.)