dev - Platform

DEVICES

The /dev directory is the interface to all available hardware devices of the system.

Devices that are of interest to Lua applications

/dev/ttySx	A serial port. The 'x' indicates the number of the serial port.
/dev/ttyS0	This is the debug console. It should not be used to connect external devices.
/dev/lpUSBx	A printer connected via USB. The 'x' indicates an USB location ID, see below.
/dev/watchdog	Provides access to the hardware watchdog.

Block devices

Block devices are used primarily for formatting a device. If you want to access the files stored on a block device, you need to access it under /media.

/dev/df0b	The on board (NOR) dataflash chip
/dev/nv0	The on board battery backed static RAM
/dev/ram0	The volatile ram disk.
/dev/mmc0a	The memory card, if present
/dev/sdUSB1aa	Example of an USB stick in USB slot 1

Classic device files

/dev/full	Trying to write to this file will always result in an No space left on device error.
/dev/null	Data written to this file will be ignored.
/dev/zero	Reading from this file will produce an endless stream of zeroes.
/dev/random	Reading from this file produces random numbers

NOTES

USB location ID

An USB location ID consists of one or more digits. Each digit numbers the port at the USB hub where the device is connected.

A device connected directly to the controller has a location ID consisting of a single digit, .e.g '1'. When using one hub, the location ID has two digits, .e.g '14': First port on controller, fourth port on hub.

Naming of USB storage devices

USB storage devices are named /dev/sdUSBxyz

x is the USB location ID, as described above.
y is the slot number at the storage device. Most flash card readers have four slots, labeled 'a'...'d'.
z is the partition number on the media. Flash memories mostly use 'a' here, while harddisks may be labeled 'a'...'d'.

A plain USB Stick: /dev/sdUSB1aa

1: First port at controller.
a: First slot.
a: First partition.

A memory card in an external card reader behind two hubs: /dev/sdUSB243ba

243: Second port at controller, fourth port at first hub, third port at second hub.
b: Second slot.
a: First partition.

Platform