The Adafruit RS-232 Full Pinout Level-Shifter Breakout lets you interface any 3.3 V microcontroller or single-board computer with RS-232 devices using all 8 data/flow-control signals. Built around the trusted TI MAX3243, it generates the required positive and negative voltages internally and provides 5 input and 3 output channels of level shifting at up to 250 Kbps.

RS-232 uses ±6 to ±10 V signal levels — far outside the range of standard 3.3 V or 5 V logic. This breakout handles all the voltage generation and conversion, and comes fully assembled with a DE-9F connector ready to plug directly into your RS-232 device.

Key Features

• MAX3243 Level Shifter – 8 channels (5 input, 3 output) for full RS-232 pinout including RTS, CTS, DTR, DSR, DCD, and RI
• 3.3 V Power & Logic – Runs on 3.3 V, compatible with modern microcontrollers (many older RS-232 chips require 5 V)
• Up to 250 Kbps – Suitable for most RS-232 communication needs
• DE-9F Connector – Standard 9-pin D-Sub connector for direct plug-in to RS-232 devices
• Valid Signal Output – Logic-level output goes high when RS-232 signal voltages are detected (connection indicator)
• Off/Tri-State Pin – Set high to tri-state all pins for power reduction
• Fully Assembled – UART side for low-voltage logic, DE-9F side for RS-232; header included for breadboard use

Ideal For

• Interfacing with industrial and telco equipment
• Retro computing and legacy device communication
• Barcode scanners, modems, and serial terminals
• Any project requiring full RS-232 flow control signals

Package Contents

• 1× Adafruit RS-232 Full Pinout Level-Shifter Breakout (fully assembled with DE-9F connector)
• 1× Header strip (soldering required for breadboard use)