This repository contains reverse engineering information about the following boards:

• Linsn RV901T HUB75 LED driver card (which uses a Spartan 6 LX16 FPGA)
• ColorLight 5A-75B V6.1 and V7.0 (which use a Lattice ECP5-25 FPGA)

These are known as a "Receiver Card". Its stock function is to receive and forward framebuffer data using a proprietary protocol (from a "Sender Card") and blit out control signals to LED panels (via shields, like a HUB75 shield).

Chubby75 is a project to reverse engineer, document and provide tools for these cards.

This project is only in the beginning stages. You can find information about it here.

As it contains a user-reprogrammable Spartan 6 FPGA (LX16, 14k 'logic cells', 9112 LUTs) and 2x GbE, it has potential to be usable as a general purpose FPGA development board, an interface card for various purposes, or a logic analyzer.

• Reverse engineered RV901T Hardware Documentation
• Reverse engineered HUB75B Hat Hardware Documentation
• Reverse engineered HUB7EB Hat Hardware Documentation
• Getting Started with the RV901T Board: JTAG Connector and LED blink

There is hardware documentation available, which includes WIP information about mapping from the FPGA balls / IO into various peripherals on board and connectors.

You can buy these boards from eBay, Aliexpress, Taobao. As of today (2019/01/26), these boards are around €18 (including S&H) on Aliexpress.

• Hardware RE:
  • Clocking
  • LED and Button
  • PHY0
  • PHY1 - partially
  • J600
  • J601
  • JP5 - SPI flash connector?
  • JP4
  • JP2
  • U100 - SDRAM
• Migen integration:
  • Platform Defintion (platform.py)
• LiteX integration
  • Sample project (sdram_test.py)
• LiteEth integration:
  • Sample project (rgmii_test.py)

Thanks to Niklas Fauth and Jan Henrik for donating two boards and partially tracing out the PHYs, and delayering the PCB.

Thanks to carrotIndustries for assisting with the preliminary RE process at Glühweinprogrammiernacht 2018.

Thanks to enjoy-digital for reverse engineering the RGMII interface, implementing an S6 RGMII PHY interface, and the sample target files.

Thanks to jeanthom for reverse engineering the SDRAM interface.

Thanks for informatic for reverse engineering the HUB75B hat.

CC0 - to the extent possible under law, the person who associated CC0 with this work has waived all copyright and related or neighboring rights to this work.