Amazon.com: Geekstory CP2102 6 in 1 USB-UART Serial Adapter Module USB to TTL 485 232,TTL to 232 485,RS232 to 485 + 4P Dupont Cable Jumper Wire Female to Female, for Windows, Linux,
USB-TO-SPI Bridge Chip - Tech Briefs
USB SPI click - Breakout board for MCP2210 USB to SPI converter