If you get a USB-Serial adapter from somewhere else, please check the cable colors of it at the vendor. The RX pin on the adapter should be connected to the TX pin on the Cubieboard and the adapter TX pin vice versa, so that the serial wires are crossed.
The CubieBoard (Rich package) is currently supplied with a Prolific PL2303 USB cable. This cable provides VCC power on the red cable. The Cubieboard does NOT require power (red cable), and it may damage your board if connected. The CubieBoard provides a pin header with 4 pins for TTL UART connection.
Warning! Some PL2303 wires, like the PL2303HX 5V, could damage your Cubieboard. See UART-USB Dongle for more details.
If you are using the supplied PL2303 cable, then the connection should be as follows:
|Cable||Pin on Cubieboard|
|MUST NOT BE CONNECTED||VCC|
Driver for the PL2303 is inside the kernel. It will work with default settings.
OS X Driver
The opensource driver on github works and the binary version is on the link below.
- https://github.com/downloads/berg/osx-pl2303/osx-pl2303-0.4.1-failberg.pkg (could someone confirm that this works?)
It is at least confirmed to work on Mac OS X 10.6.8 32 bit version.
There is also a vendor-made driver;
- Go to http://www.prolific.com.tw/US/index.aspx
- Click support
- Login with GUEST / GUEST
- Click on "click here for PL2303 USB to Serial drivers"
- half way down, download the file md_PL2303_MacOSX10.6_dmg_v1.4.0.zip
Windows Driver for Prolific PL2303 is installed automatically. If your "Device Manager" mark the PL2303 device (Prolific USB-to-Serial Comm Port) with yellow exclamation mark and the status of the device shows "code 10", then you probably got counterfeit (fake) cable or you are using the cable with Windows 8. In both cases you just have to install older version of Prolific drivers (1.6.0, 1.7.0, 1.8.0 or later won't work).
- For PL2303 HXA, XA (to check your version use the utility provided in latest Prolific drivers.)
- Installer version & Build date: 1.5.0 (2011-10-21)
- Windows XP (32 & 64-bit) WDM WHQL Driver: v18.104.22.168
- Windows Vista/7/8 (32 & 64-bit) WDF WHQL Driver: v22.214.171.124
- Download (Mirror #1, #2)
Linux / OSX
'If you are using OSX, you should replace /dev/ttyUSB0 with /dev/tty.PL2303-00001014'
cu is an utitlity that comes with popular system distributions like Fedora, Debian, Ubuntu, NetBSD, etc. It can be used to talk to a device connected to a serial port. On Linux with the serial cable as the only USB serial port
stty -F /dev/ttyUSB0 -crtscts # turn off hardware flow control - the cable has no wires for that cu -s 115200 -l /dev/ttyUSB0
Another option is GNU screen
screen /dev/ttyUSB0 115200
With gtkterm, a serial terminal tool with minimum graphic interface :
gtkterm -p /dev/ttyUSB0 -s 115200
You might get the following error when trying to access the serial port
$ sudo cu -s 115200 -l /dev/ttyUSB0 cu: open (/dev/ttyUSB0): Permission denied cu: /dev/ttyUSB0: Line in use
The reason why you cannot access the serial port even if you are root, is due to additional kernel-level security restrictions (such as AppArmor or SELinux). For the case of Ubuntu, which has AppArmor, your account needs to be member of the group dialout. To add your account to the dialout group, run the command
$ sudo usermod --append --groups dialout myusername
Then, log out and log in again.
Consider some other solutions listed here.
It seems the default setting for uBoot and terminal serial is 115200 8N1:
|Serial line||/dev/ttyUSB0 or COM1|
Windows users can determine proper COM port from Device Manager.
See http://pastebin.com/p77V8xdC for sample output. It shows the boot process of the Cubieboard.