The Radxa Rock Pro, running the Linaro (ubuntu) 14.04 Server image, provides access to the serial console. This can be very handy for troubleshooting if the device isn’t connected to a network.

In order to use the SparkFun FTDI Basic USB-to-serial, you’ll need some jumper wires, in addition to the FTDI device.

DO NOT CONNECT the FTDI 3.3V to the Radxa Rock.

Using the jumpers (because the pins are arranged on the SparkFun device in a different order than on the Rock Pro) connect the three as follows:

FTDI Basic      Rock Pro

Gnd                  GND

TXD                  RX

RXI                    TX

You can then use a Linux terminal emulation program, such as minicom. Set the data rate to 115,200, the protocol to 8, None and 1 and disable hardware flow control. You may have to press the Enter key  when you first connect. If you send a BREAK condition, you’ll enter the FIQ debugger mode. Type “console” and you’ll leave the debugger mode.