The Adafruit RS-232 Full Breakout with DE9-M 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.

This version features a DE9-M (male pin) connector — check the product photos to confirm it matches the device or cable you want to connect to.

Key Features

• MAX3243 Level Shifter – 8 channels (5 input, 3 output) for full RS-232 pinout including RTS, CTS, DTR, DSR, DCD, and RI
• DE9-M Male Connector – 9-pin D-Sub male connector for direct plug-in to RS-232 devices or cables
• 3.3 V Power & Logic – Runs on 3.3 V, compatible with modern microcontrollers
• Up to 250 Kbps – Suitable for most RS-232 communication needs
• 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, DE9-M side for RS-232; headers included for breadboard use

Also Consider

• RS-232 Full Pinout Level-Shifter Breakout (DE9-F) – Same board with a female DE-9 connector

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 Breakout with DE9-M (fully assembled)
• 1× Header strip (soldering required for breadboard use)