Raspberry Pi - PL2303 USB To UART (TTL) Communication Module V2, USB-A Connector
Amazon.com: USB to TTL Serial 3.3V UART Converter Cable with FTDI Chip Terminated by 6 Way Header, Works with Galileo Gen2 Boards/BeagleBone Black/Minnowboard Max and More : Electronics
USB to TTL UART Uploader Module CH340 | Makers Electronics