This connector includes power and three serial buses: Asynchronous, I2C, and SPI. The connector layout was specified by Olimex Ltd and declared an open-project.
|1||3.3V||+3.3 volt power supply|
|3||TxD||Transmit Data for Async Serial bus OUT|
|4||RxD||Receive Data for Async Serial bus IN|
|5||SCL||Clock for I2C bus OUT|
|6||SDA||Bidirectional Serial Data for I2C bus|
|7||MISO||Serial Data In for SPI bus IN|
|8||MOSI||Serial Data Out for SPI bus|
|9||SCK||Clock for SPI bus OUT|
|10||SSEL||Slave Select for SPI bus OUT|
Direction is relative to host board.
Pins 3,4,7,8,9 conforms to Push-Pull logic, Pins 5,6 Open-Drain logic. All pins are conform to 3.3 volt digital logic