UEXT

Universal expansion connector (UEXT) is a connector layout supporting three common serial communication protocols. UEXT ports can be found on many devices made by Olimex Ltd. a Bulgarian Printed circuit board manufacturer known for their evaluation and development boards for microcontrollers and other electronic components.

Physical characteristics

The UEXT interface is a pin header that consists of ten pins (two rows of five, with 0.1" spacing). The socket is mated with a 2x5 (10-pin) IDC female connector. The cable assembly commonly used to interconnect with the UEXT is referred to as a 10-pin IDC Connector Ribbon Cable. A similar cable is more commonly used for providing JTAG connections with AVR microcontroller development boards, such cables are readily available and can be bought for less than US$2

Electrical characteristics

The UEXT connector presents I2C, SPI, and serial communications, as well as +3.3V power and common ground. The serial communications conform to RS-232 but may require level-shifting to operate with some equipment.

Similar connectors

Some devices use a layout based on the UEXT connector but have chosen not implement all of the functionality. In particular the RS-232/serial connection may have been omitted. In these cases the spare pins are usually assigned other purposes, such as connecting to a device reset line, so care should be taken to check the exact connector layout on the schematic of a particular device.