RS232 to TTL serial cable pinout diagram @ pinoutguide.com
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
RS232 vs TTL: Beginner Guide to Serial Communication - Latest Open Tech From Seeed
RS232 to TTL Converter Module
Serial Comm TTL-232-5P Port-Powered Plug-N-Play RS-232 to 5V TTL Converter | eBay
TTL-232R-5V-PCB FTDI | Mouser
RS232 to 3.3V TTL Converter / Adapter
FTDI Serial TTL-232 USB Cable : ID 70 : $19.95 : Adafruit Industries, Unique & fun DIY electronics and kits