UX2: Universal Extension Bus

UNDER CONSTRUCTION - LIABLE TO CHANGE

UX2 is an open source, connector-agnostic, board-to-board communication bus. It supports multiple interface protocols, facilitating connection to a vast range of commerically available add-on modules from popular venodors.

Quick Reference

There are four variants which determine the function of the outer pins...

UX2-GPIO – four GPIO

UX2-ALT – two GPIO, one addtional I2C

UX2-1IS – 1-Wire, Interrupt and Sound-Wire
Note: Not suitable for hosts that rely on energy harvesting

UX2-I2C – two additional I2C

See also: Tips on pin variant selection

Pins / Protocols

UX2	Protocol
	GPIO
	1-WIRE
	INTERRUPT
	POWER
	UART / Asynch
	I2C / SMBus
	SPI
	SOUND-WIRE

Protocols

• GPIO – General Purpose Input/Output
• Interrupt – wake master/host MCU via slave/module triggered interrupt
• UART / Async - serial communication bus
• Sound-Wire

Modules

UX2 is compatible with hundreds of commercially available and open source modules. For more information, see Modules.

Sound-Wire components

UX2-1IS pin variant, with following wiring:

• SWD connects to Data
• SWC connects to Clock or Clk

Note: In circuit schematics, the clock connections are often omitted for sake of clarity (focus is on the data); the clock connection is always required regardless.

RS232, RS485, IRDA, USB, SD/MMC

Use the UEXT bus (see UEXT section above) in conjunction with Olimex Interface Modules.

Any pin variant can be used as they don't affect the UEXT pins.

License

See License.