If you want to interface with telco, retro, or industrial equipment, you’ll probably run into RS-232 interfaces. The Adafruit RS232 Full-Pinout Breakout with 8 Channels of UART to RS-232 Level Shifters is your friend in such cases. It gives you 5 input and 3 output channels of level shifting and takes care of the high/negative voltage generation all in a low-cost breakout board. We use the trusty MAX3243 from TI, a classic chip part of the MAX232 lineage, so you know it will work great for all your RS-232 needs, up to 250Kbps.

RS-232 is what we had before USB: a 9- or 25-pin D-Sub connector that allowed data plus flow control lines. Many folks may remember these interfaces were used for mice, modems, barcode scanners, teletypes, and more. We still find devices sold with RS-232 ports, although many folks use a USB to RS-232 adapter these days.

Features:

1. Operates With 3-V to 5.5-V VCC Supply
2. Single-Chip and Single-Supply Interface for IBM™ PC/AT™ Serial Port
3. RS-232 Bus-Pin ESD Protection of ±15 kV Using Human-Body Model (HBM)
4. Meets or Exceeds the Requirements of TIA/EIA-232-F and ITU V.28 Standards
5. Three Drivers and Five Receivers
6. Operates Up To 250 kbit/s
7. Low Active Current: 300 μA Typical
8. Low Standby Current: 1 μA Typical
9. Accepts 5-V Logic Input With 3.3-V Supply
10. Serial-Mouse Drive ability

Package Includes:

1 x Adafruit RS-232 Full Pinout Level-Shifter Breakout