SparkFun FT231X Breakout

The SparkFun FT231X Breakout is the modern evolution of our classic FTDI boards. Built around the FT231X chip, this board does everything the standard "Basic" boards do (like programming Arduinos) but adds full access to the chip's capabilities. We've updated the connector to a standard Micro-B USB, so you can use the cables you likely already have on your desk.

Full Hardware Handshaking

The coolest thing about this board? We didn't just break out the standard six pins. We broke out ALL the pins to the sides of the board. This gives you complete access to the full UART hardware handshaking signals (RTS, CTS, DTR, DSR, DCD, RI), making this board significantly more capable for advanced serial applications and hacking than standard breakouts.

Arduino Compatible (DTR)

Despite the extra features, we ensured it remains a drop-in programmer for your existing projects:

• Standard Layout: The FT231X Breakout retains the classic 6-pin header layout used by the Arduino Pro Mini and LilyPad.
• Auto-Reset: This board also breaks out the DTR pin, allowing it to automatically reset your Arduino when uploading a new sketch—so you don't have to time a "reset button press" manually.

Voltage Flexibility

Unlike our standard FTDI Basics, which are sold as specific 5V or 3.3V models, this board is designed to be the only adaptor you need on your bench:

• Selectable Power: A jumper on the back lets you set the VCC output to 3.3V or 5V. (Ships default to 5V, but easily changeable with a cut and a solder blob.
• 5V Tolerant: Even when operating at 3.3V, the FT231X I/O pins are 5V tolerant, allowing safe interfacing with a wide range of logic levels down to 1.8V (with external pull-ups).

• Schematic
• Eagle Files
• Datasheet (FT231XS-U)
• FTDI Drivers
• GitHub