RS232
Pololu USB AVR Programmer v2.1
USB to TTL Serial Cable (5V VCC)
MAX3232 Breakout
CP2102N USB-to-Serial Adapter
FTDI SmartBasic
RS232 Shifter SMD
TTL-232R USB 5V cable 3.3V IO
Dual RS232 Ethernet converter
Enclosure DB9 GREY
SparkFun USB UART Serial BoB - CY7C65213
SparkFun FT231X Breakout
USB to Serial BoB - FT232RL
RS232 Shifter SMD without DB9
Deluxe Serial Adapter (Kit)
Serial Device Server Module (IPv4/IPv6)
RS232 Serial Device Server (IPv4/IPv6)
SparkFun Beefy 3 - FTDI Basic Breakout
SparkFun Serial Basic Breakout - CH340G
USB to TTL Serial Cable
TTL-232R USB 5V cable 5V IO
LAWICEL - FTDI FT232 Basic BoB
FTDI Basic Breakout - 5VDC
FTDI Basic Breakout - 3.3VDC
USB to TTL (3.3V) Serial Cable for RPi