serdisplib SVNwiki

disclaimer / info

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• this page deals with using a framebuffer device with serdisplib.
• i'm not responsible for the content of external web pages
• english is not my native language. please keep that in mind (corrections of english grammar and formulations are very welcome!)
• use the most recent SVN trunk revision to test this driver

description

This driver supports framebuffer devices that are supported by linux framebuffer support. even an attached touchscreen may be used if it supported by linux.

Attention: this is a linux-only driver at the moment.

specifications

resolution
variable

colours
variable

adjustable contrast
no

name in serdisplib
"FRAMEBUFFER" (example: serdisp_open(sdcd, "FRAMEBUFFER", "");)

availability
SVN trunk (2.x): yes
SVN 1.98.x branch: no
SVN 1.97.x branch: no

connecting the framebuffer device

intro

the framebuffer device must already be configured and initialised by linux - including resolution and colour depth.

important

• the framebuffer device needs read/write-access for serdisplib
• the touchscreen device needs read-only access for serdisplb
• file-rights should be set using udev-rules (including a symlink for the touchscreen device)
• the framebuffer device usually is something like /dev/fbX (X ... number of framebuffer)
• the touchscreen device usually is an unpredictable input device (like /dev/input/input47) so it is best to let udev create a symlink

example for configuration of the touchscreen:

SUBSYSTEM=="input",ATTRS{idVendor}=="1ac7", ATTRS{idProduct}=="0001", GROUP="uucp",MODE="0660", SYMLINK+="input/touchscreen"

• idVendor 1ac7 / idProduct 0001 is for an E2i touchscreen (this can be found for example in Mimo 720s USB monitors)
• group should be changed according to ones needs
• SYMLINK would create a symlink for the touchscreen device which can be accessed via /dev/input/touchscreen
• this udev-rule should be called as late as possible (thus it should be placed in a rule like 99-somerules.rules)

examples

• configuration in lcd4linux

   Display SerDispLib {
     Driver 'serdisplib'
     Model 'framebuffer'
     Options 'FBDEVICE=/dev/fb1;TOUCHDEVICE=/dev/input/touchscreen'
   }
  

• configuration in graphlcd

   [serdisp_framebuffer]
   Driver=serdisp
   Controller=framebuffer
   Options=FBDEVICE=/dev/fb0
  
   [mimo720s]
   Driver=serdisp
   Controller=framebuffer
   Options=FBDEVICE=/dev/fb1;TOUCHDEVICE=/dev/input/touchscreen;TOUCHSWAPY=1
  

• calling test program testserdisp

    testserdisp -n framebuffer -o 'FBDEV=/dev/fb1'
    testserdisp -n framebuffer -o 'FBDEV=/dev/fb1;TOUCHDEVICE=/dev/input/touchscreen;TOUCHSWAPY=1;ROTATE=90'
  

passing options through serdisp_init():

intro

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

examples:

  serdisp_init(sdcd, "FRAMEBUFFER", "FBDEV=/dev/fb1");
  serdisp_init(sdcd, "FRAMEBUFFER", "FBDEV=/dev/fb1;TOUCHDEVICE=/dev/input/touchscreen;TOUCHSWAPY=1;ROTATE=90");

additional options

identifier
short
remark
default

FBDEVICE
FBDEV
set the framebuffer device
/dev/fb0

REPORTDAMAGE
DAMAGE
report damage (0: no damage report, 1: automatic, 2: udlfb, 3: ugly (send '\n' after refresh)
1

TOUCHDEVICE
TSDEV
set the touchscreen device
(none)

TOUCHSWAPX
TSSWAPX
swap x-asis of touchscreen
0

TOUCHSWAPY
TSSWAPY
swap y-asis of touchscreen
0

ranges, aliases

identifier
range
aliases

REPORTDAMAGE
0, 3
NONE=0,OFF=0,AUTO=1,UDLFB=2,UGLY=3

TOUCHSWAPX
0 - 1
OFF=0,ON=1,NO=0,YES=1

TOUCHSWAPY
0 - 1
OFF=0,ON=1,NO=0,YES=1

options for specific framebuffer devices

model
touchscreen
touchscreen options

Mimo 720s
yes
TOUCHSWAPY=1

history

• 2013-05-19: first release of documentation