Waveshare PL2303 USB UART Board (mini) TXD /RXD /POWER LED UART interface VCC | eBay
WITMOTION USB-UART 6-in-1 USB to Serial Converter, Multifunctional (USB to TTL/RS485/232, TTL-RS232/485, 232 to 485), Universal Adapter Module with CP2102 Compatible with Windows 7/8/10,Linux, Arduino : Amazon.ca: Electronics