litex-boards VS chubby75

Initial LiteX support for LimeSDR mini V2 is available on LiteX repository. You should be able to boot many of the RISC-V cores using just that. [Crowd Supply Update]

Here is a list of boards that are supported "out of the box" by Litex: https://github.com/litex-hub/litex-boards

There may be other similar inexpensive boards available where you live based on newer FPGA families such as Gowin. The list of LiteX-supported boards keeps growing! https://github.com/litex-hub/litex-boards/tree/master/litex_boards/targets

A starting point could be the litex-boards readme, it will give you an idea of what's possible. A $10+ ECP5 can interface with 8-128 MiB of SDRAM, and even DDR3 SDRAM for larger ones. An example board is the ULX3S, with available schematics and KiCad project.

This Colorlight board already has support for Litex. See [here](https://github.com/litex-hub/litex-boards/blob/master/litex_boards/targets/colorlight_5a_75x.py). I haven't tried it myself, but it might be useful to start with that and see if you can get some ideas about what's going wrong?

DE10-Nano used to be ~$100 2 years ago before FPGA vendors decided to stop manufacturing while bumping prices.

$30 is a good price for FPGA dev board, requires a little creativity https://github.com/q3k/chubby75/tree/master

I am now trying to make use of the on-board Ethernet PHYs, which on my revision of the board are Realtek RTL8211FD chips. More details on the board V8.0 revision here. And the Realtek datasheet is here.

Rather than designing your own PCB, I suggest that you use a ColorLight 5A-75 LED driver board. These are commercial boards that are designed to drive LED panels. They contains Lattice ECP5 FPGAs and have been completely reverse engineered for hobby use. They are very cheap, around $20 on AliExpress.