The serialPOS Driver

This section talks about using LCDproc with a point of sale ("POS") character-display.

The serialPOS driver is currently working with the AEDEX emulation protocol, and may support Epson ESC/POS and Logic Controls. It can be extended to work with various other protocol displays.

The driver should operate most character POS displays with a serial (RS-232) input. Because these displays use a standardized protocol, if the protocol is supported by your display, it should work as expected. Feedback is welcome.

Table 5.23. serialPOS: Emulation Protocol Status

ProtocolDisplay testedCurrently SupportedRemark
AEDEXEmaxYes
IEE No
EpsonNoYes
Emax No
IBM No
Logic ControlsNoYes
Ultimate No


(): Feature not tested.

Connecting The Display

Connecting the display should consist of simply plugging it into your computer's RS-232 serial port. Because these displays typically support full RS-232, no additional wiring is needed. If your computer does not have such a port (many newer computers don't), you can use a USB to serial adapter with a driver provided by the adapter manufacturer.

If your display supports a pass-through function, you can connect an RS-232 keyboard or terminal to the pass-through port. This will allow you to input keystrokes to LCDproc and control features and menus. Use the pass-through keyboard's arrow, delete, and return keys by default.

Note

If your display supports a pass-through function, but you do not have another RS-232 device connected to the pass-through port, you may experience hangs if an improperly formatted command sneaks through. This is because the display is waiting for the pass-through device to accept the data and a blocking state is created within the display. You can either connect another RS-232 device or use a wire to jumper the CTS and RTS pins together within the display.

Configuration in LCDd.conf

[serialPOS]

Device = DEVICE

Device to use in serial mode. Usual values are /dev/ttyS0 or /dev/cu.usbserial. Default is /dev/lcd.

Size = WIDTH x HEIGHT

Specifies the size of the VFD in characters. If not given, it defaults to 16x2.

Type = { IEE | AEDEX | Epson | Emax | IBM | LogicControls | Ultimate }

Set the communication protocol to use with the POS display. If not specified it defaults to AEDEX. Currently, only AEDEX is supported.

Speed = { 1200 | 2400 | 9600 | 19200 | 115200 }

Set the the baud rate communication with the POS display. If not given the default of 9600 is used.