Extension Port

What the Extension Port Does

The RJ-12 connector functions as a compact combination of serial communication and GPIO expansion, enabling extensions to communicate directly with LeafKVM firmware.

Third-party users are free to design their own add-ons — the port is not limited to official accessories.

LeafKVM’s firmware is being developed with community extensibility in mind, and future updates will introduce hooks for custom hardware integrations.

ATX power control is planned as a roadmap feature and will be supported through the extension port.

Build Your Own Extensions

LeafKVM exposes power rails, serial communication, and general-purpose I/O through a compact RJ-12 connector.

Extension Port Pinout

Pin	Signal	Notes
1	+5V	Direct passthrough from internal 5V rail (NO direction control).
2	GPIO	3.3V logic level, includes a 22 Ω series protection resistor.
3	+3.3V	Powered through an internal 1 Ω current-limiting resistor.
4	TX	UART TX (3.3V), includes a 22 Ω series protection resistor.
5	RX	UART RX (3.3V), includes a 22 Ω series protection resistor.
6	GND	Ground reference.