Adafruit RS232 Pal - Two Channel UART to RS-232 Level Shifters - MAX3232E

If you're looking to interface with telco, retro or industrial equipment you'll probably run into RS-232 interfaces. The Adafruit RS232 Pal - Two Channel UART to RS-232 Level Shifters is your friend in such cases, giving you two duplex channels of level shifting and taking care of the high/negative voltage generation all in a low cost breakout board. The trusty MAX3232E is used, a classic chip that is part of the MAX232 lineage so you know it will work great for all your RS-232 needs, up to 250Kbps.

If you want to use a microcontroller or microcomputer to chat with a RS-232 then thankfully all you need is a serial port / UART (something just about any microcontroller has) and a level shifter. The level shifter is required because while most UARTs are 0-3.3V or 0-5V logic level, RS-232 requires +-6 to +-10V. That means a specialized shifter is required, one that can generate the extra high and low voltages and also safely convert the logic levels.

This breakout comes fully assembled with a UART side for low voltage power/logic level and an RS-232 side for high voltage signals plus the doubled and negative voltage rails in case you need to reference them. A bit of header is included so you can solder it to a breadboard in a few minutes.