Amazon.com: #10Gtek# USB to ESP8266 ESP-01 Serial Adapter, USB to TTL Driver Serial Compatible with Arduino, Pack of 2 : Electronics
Amazon.com: HiLetgo 2pcs Xbee Adapter Xbee USB Adapter FT232RL USB to Serial Adapter for XBEE Arduino : Electronics
Type-C USB3.1 Female Connector Adapter Test Board USB 3.1 24P 24Pin Socket Base PCB Board for Arduino USB 2.0 DIY - AliExpress
Adaptador USB-Serie TTL (CH340) compatible con Arduino Mini Pro Conexión DTR y Raspberry - La Tienda del Tecnófilo
Amazon.com: 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 : Electronics
USB Adapter for NRF24L01+ | Makerfabs Electronics
XBee USB Adapter - Corzotech
Micro SD Card and USB Reader (Arduino-Compatible) — Maker Portal
How to Use Arduino as USB to Serial Converter | Microcontroller Tutorials
TZT FT232RL FTDI USB 3.3V 5.5V to TTL Serial Adapter Module for Arduino FT232 Pro Mini USB TO TTL 232 - AliExpress
How to use an Arduino as a USB to TTL converter || Arduino tutorial - YouTube