linux4media l4m320t
usb colour display module

L4M320T usb display modules are colour display modules with touchscreen and optional support for IR-decoding of certain remote controls and were developed by www.digitaldevices.de, but are now discontinued.

front and back of the display. when connecting an IR-sensor to the display several remote controls could also been used.

test image generated by testserdisp (with option ROTATE=270)

the L4M320T is not claimed by any standard kernel module and no kernel module providing ioctl is existing yet. thus only libusb is supported at the moment.

• this driver supports two different categories of firmwares: one without and one with support for IR-controls.
• firmware versions without support for IR have USB productID ee20, firmware versions with support for IR have productID ee21.
• libusb needs to be installed on the system for serdisplib to be able to support this display module! (libusb will be dynamically loaded by serdisplib via dlopen()).

• the vendor/production IDs for display modules without IR-support are: 4243/ee20 (hex)
• the vendor/production IDs for display modules with IR-support are: 4243/ee21 (hex) or for newer controllers: 23ae/ee21 (hex)
• the device-string for accessing the dislay is: 'USB:4243/ee20', 'USB:4243/ee21', or 'USB:23ae/ee21' respectivaly.
• the following examples will contain vendor ID 4243. replace with 23ae if required.
• the following examples will contain production ID ee21. replace with ee20 if required.
   
• default device: 'USB:4243/ee21'

using the third parameter of serdisp_init(), driver specific options and custom wiring can be set.
common information about passing options and customisable wiring can be found in a separate document.

    examples:
      serdisp_init(sdcd, "L4M320T", "INVERT=YES;ROTATE=90");
      serdisp_init(sdcd, "L4M320T", "BRIGHTNESS=80");
    

this small utility is automatically compiled if serdisplib is configured with support for l4m320t-modules. it supports the following features:

• firmware update
• calibrate touchscreen
• changing the boot logo(s)
• setting alarm

the utility can be found in tools/ after compiling the library.

some options only work with recent firmware versions!

  l4m320t_tool [<options>]

  Options: (default values in squared brackets)
    -p dev|port      output device or port, default: 'USB:4243/ee21'
    -i               print firmware version information and serial number
    -B id        [0] show a stored bootlogo; id=[0, 2]
    -c value     [5] contrast / brightness; value=[0, 10]
    -a "HH:MM"       set alarm time
    -d "%6543210"    set alarm days (bit field, to be entered as hexadecimal or decimal)
                       bit 6: saturday   bit 5: friday
                       bit 4: thursday   bit 3: wednesday
                       bit 2: tuesday    bit 1: monday
                       bit 0: sunday
                     examples:
                       -d 0x7F: %1111111 -> all days
                       -d 0x41: %1000001 -> saturday and sunday
                       -d 0:    de-activate alarm
    -f imagefile(s)  change up to three bootlogos (240x320, readable by libgd)
    -u firmwarefile  update firmware (.hex or .bin)
    -C               calibrate touchscreen
    -y               enforce certain actions (e.g. overwrite newer firmware version with older one
    -1               display module with firmware version < '90D'
    -v               verbose (-v repeated: <= 2: log to syslog, >= 3: log to stderr, >= 5: log to stdout)
    -V               version information
   

  l4m320t_tool                                  # show default (= first) bootlogo
  l4m320t_tool -B 1                             # show second bootlogo
  l4m320t_tool -i                               # print firmware version and calibration information
  l4m320t_tool -p "USB:4243/ee21" -i            # same, but set custom device path
  l4m320t_tool -1                               # add -1 for firmware version without IR-support (prodID ee20)
  l4m320t_tool -C                               # calibrate touchscreen
  l4m320t_tool -u firmware.hex                  # flash new firmware (.hex or .bin, .bin additionally requires option -y)
  l4m320t_tool -y                               # force an action refused by the tool (eg. downgrading firmware)
  l4m320t_tool -f bootlogo.png                  # change first bootlogo
  l4m320t_tool -f bl0.png bl1.png bl2.png       # change all three bootlogos
  l4m320t_tool -a "23:30" -d 0x41               # set alarm at 23:30, saturday (bit6) and sunday (bit0)
  l4m320t_tool -a "23:30" -d 0x7F               # set alarm at 23:30, all days
  l4m320c_tool -a "23:30" -d all                # set alarm at 23:30, all days (all = alias for '0x7F')
  l4m320c_tool -d 0                             # de-activate alarm
   

custom bootlogo, uploaded with l4m320t_tool	calibrating the touchscreen