#
# $Id: README.Drivers,v 1.4 2001/03/09 13:08:11 ltoetsch Exp $
#

How to write new display drivers for lcd4linux

If you plan to write a new display driver for lcd4linux, you should follow
this guidelines:

* use Skeleton.c as a start point.
  You might also have a look at Text.c

* create a new sourcefile <drivername>.c and add it to the bottom of
  Makefile.am

* add an entry to configure.in

* there's no need for a <drivername>.h

* create one (or more) unique display names (your driver will be selected by
  this name in the 'Display'-line of lcd4linux.conf).

* include "display.h" in your driver, to get the LCD structure and various 
  BAR_ definitions

* include "cfg.h" if you need to access settings in the config file.

* create a LCD table at the bottom of your driver, and fill it with the
  appropriate values. Take care that you specify the correct bar capabilities
  of your display or driver:

  BAR_L:  horizontal bars headed left
  BAR_R:  horizontal bars headed right
  BAR_H2: driver supports horizontal dual-bars
  BAR_U:  vertical bars bottom-up
  BAR_D:  vertical bars top-down
  BAR_V2: driver supports vertical dual-bars

* edit display.c and create a reference to your LCD table:

     external LCD YourDriver[];

* extend the FAMILY table in display.c with your driver:

     FAMILY Driver[] = {
       { "Skeleton",      Skeleton },
       { "MatrixOrbital", MatrixOrbital },
       { "YourFamily",    YourDriver },
       { "" }
     };

* write the correspondig init(), clear(), put(), bar(), quit() and
  flush()-functions. There's no need to use a framebuffer and display its
  contents with the flush()- call (as in MatrixOrbital.c), you can directly
  write to the display in the put()- and bar()-functions, and use an empty
  flush()-function. But if you have a limited number of user-defined
  characters, and therefore you have to do some sort of 'character reduction'
  or similar stuff, you will have to use a framebuffer and the flush()-call. 
hor'>author</option>
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<div class='path'>path: <a href='/lcd4linux.git/log/?id=d8ce1d7743380929b6070ea2bb1b8fb2016f195b&amp;showmsg=1&amp;follow=1'>root</a>/<a href='/lcd4linux.git/log/documentation?id=d8ce1d7743380929b6070ea2bb1b8fb2016f195b&amp;showmsg=1&amp;follow=1'>documentation</a> (<a href='/lcd4linux.git/log/documentation?id=d8ce1d7743380929b6070ea2bb1b8fb2016f195b&amp;showmsg=1'>unfollow</a>)</div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/lcd4linux.git/log/documentation?id=d8ce1d7743380929b6070ea2bb1b8fb2016f195b&amp;follow=1'>Collapse</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
<tr class='logheader'><td><span title='2004-06-02 10:09:22 +0000'>2004-06-02</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_generic_text.h?id=edad39d87fae7bb48e3e4e558be6805793ec80e9&amp;follow=1'>[lcd4linux @ 2004-06-02 10:09:22 by reinelt]</a></td><td>reinelt</td><td>4</td><td><span class='deletions'>-180</span>/<span class='insertions'>+183</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
splash screen for HD44780

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@462 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-06-02 09:41:19 +0000'>2004-06-02</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/lcd4linux.conf.sample?id=246b8539fe86f8e6636e18b65b70da3169dfabd6&amp;follow=1'>[lcd4linux @ 2004-06-02 09:41:19 by reinelt]</a></td><td>reinelt</td><td>18</td><td><span class='deletions'>-114</span>/<span class='insertions'>+211</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
prepared support for startup splash screen

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@461 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-06-02 05:56:25 +0000'>2004-06-02</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_Crystalfontz.c?id=b07a5205b19d8e46596d748af8e070bfd58949e5&amp;follow=1'>[lcd4linux @ 2004-06-02 05:56:25 by reinelt]</a></td><td>reinelt</td><td>1</td><td><span class='deletions'>-2</span>/<span class='insertions'>+6</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
extended contrast range for Crystalfontz

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@460 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-06-02 05:35:55 +0000'>2004-06-02</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/lcd4linux.conf.sample?id=a4cd5b8283d5ae7788091f9670e0a5165fcef136&amp;follow=1'>[lcd4linux @ 2004-06-02 05:35:55 by reinelt]</a></td><td>reinelt</td><td>1</td><td><span class='deletions'>-0</span>/<span class='insertions'>+20</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
added i2c_sensors example to lcd4linux.conf.sample

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@459 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-06-02 05:28:06 +0000'>2004-06-02</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/documentation/xsl/xhtml.xsl?id=21d19e4dbe9a3a1f724a1963d13af21004a06e55&amp;follow=1'>[lcd4linux @ 2004-06-02 05:27:59 by reinelt]</a></td><td>reinelt</td><td>26</td><td><span class='deletions'>-0</span>/<span class='insertions'>+2405</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
added documentation tree

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@458 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-06-02 05:14:16 +0000'>2004-06-02</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/lcd4linux.c?id=491dc3d0e3ff77223118aac4712bf9ed2dac63a8&amp;follow=1'>[lcd4linux @ 2004-06-02 05:14:16 by reinelt]</a></td><td>reinelt</td><td>2</td><td><span class='deletions'>-17</span>/<span class='insertions'>+31</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
fixed models listing for Beckmann+Egle driver
some cosmetic changes

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@457 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-06-01 06:45:30 +0000'>2004-06-01</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/timer.h?id=8dc94dba6511b8db40c0e209b0ea595052650a21&amp;follow=1'>[lcd4linux @ 2004-06-01 06:45:28 by reinelt]</a></td><td>reinelt</td><td>18</td><td><span class='deletions'>-71</span>/<span class='insertions'>+241</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
some Fixme's processed
documented some code

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@456 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-06-01 06:04:25 +0000'>2004-06-01</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugin_sample.c?id=a581675c3951031bdc1b71fa654d0dadcc191397&amp;follow=1'>[lcd4linux @ 2004-06-01 06:04:25 by reinelt]</a></td><td>reinelt</td><td>2</td><td><span class='deletions'>-25</span>/<span class='insertions'>+25</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
made README.Plugins and plugin_sample up to date.

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@455 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-31 21:23:16 +0000'>2004-05-31</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_MatrixOrbital.c?id=07afe02801bd274932a1dccdbe0ed27e782a5c80&amp;follow=1'>[lcd4linux @ 2004-05-31 21:23:16 by reinelt]</a></td><td>reinelt</td><td>1</td><td><span class='deletions'>-37</span>/<span class='insertions'>+49</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
some cleanups in the MatrixOrbital driver

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@454 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-31 21:05:13 +0000'>2004-05-31</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugin_pop3.c?id=10ff23f9cdef25d4140e6c802c373aaf48270fee&amp;follow=1'>[lcd4linux @ 2004-05-31 21:05:13 by reinelt]</a></td><td>reinelt</td><td>5</td><td><span class='deletions'>-77</span>/<span class='insertions'>+111</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
fixed lots of bugs in the Cwlinux driver
do not emit EAGAIN error on the first retry
made plugin_i2c_sensors a bit less 'chatty'
moved init and exit functions to the bottom of plugin_pop3

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@453 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-31 16:39:06 +0000'>2004-05-31</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/hash.c?id=4e1eaa7205d8b7fbc64dc685d864b385a25602be&amp;follow=1'>[lcd4linux @ 2004-05-31 16:39:05 by reinelt]</a></td><td>reinelt</td><td>11</td><td><span class='deletions'>-180</span>/<span class='insertions'>+535</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
added NULL display driver (for debugging/profiling purposes)
added backlight/contrast initialisation for matrixOrbital
added Backlight initialisation for Cwlinux

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@452 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-31 06:27:34 +0000'>2004-05-31</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/ChangeLog?id=61bd7f7bf2cef22b8d867ad7b168e4422ffd94f6&amp;follow=1'>[lcd4linux @ 2004-05-31 06:27:34 by reinelt]</a></td><td>reinelt</td><td>1</td><td><span class='deletions'>-0</span>/<span class='insertions'>+40</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
ChangeLog update

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@451 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-31 06:24:42 +0000'>2004-05-31</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/lcd4linux.conf.sample?id=a53d8337c13f485875cad24edf74b0287b37600b&amp;follow=1'>[lcd4linux @ 2004-05-31 06:24:42 by reinelt]</a></td><td>reinelt</td><td>2</td><td><span class='deletions'>-7</span>/<span class='insertions'>+29</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
fixed symlink security issue with the image driver

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@450 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-31 05:38:02 +0000'>2004-05-31</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_USBLCD.c?id=ea5453f570c5186379745a10054280f47a809299&amp;follow=1'>[lcd4linux @ 2004-05-31 05:38:02 by reinelt]</a></td><td>reinelt</td><td>8</td><td><span class='deletions'>-42</span>/<span class='insertions'>+94</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
fixed possible bugs with user-defined chars (clear high bits)
thanks to Andy Baxter for debugging the MilfordInstruments driver!

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@449 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-31 01:31:01 +0000'>2004-05-31</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_MilfordInstruments.c?id=0bda5dcd7faa2198fe972aa85b8c72cb0b666554&amp;follow=1'>[lcd4linux @ 2004-05-31 01:31:01 by andy-b]</a></td><td>andy-b</td><td>1</td><td><span class='deletions'>-10</span>/<span class='insertions'>+12</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
fixed bug in Milford Instruments driver which drew extra graphics chars in
odd places when drawing double bars. (the display doesn't like it if you put
the escape character 0xfe inside a define char sequence).

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@448 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-30 08:25:50 +0000'>2004-05-30</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/lcd4linux.conf.sample?id=f40bd8007746a5a012f01cd58b4f0f94a36709b3&amp;follow=1'>[lcd4linux @ 2004-05-30 08:25:50 by reinelt]</a></td><td>reinelt</td><td>2</td><td><span class='deletions'>-30</span>/<span class='insertions'>+92</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
Crystalfontz 631 driver finished

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@447 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-29 23:30:20 +0000'>2004-05-29</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_Image.c?id=f6aa208883850f97d72813b281b106ca184d94f7&amp;follow=1'>[lcd4linux @ 2004-05-29 23:30:20 by reinelt]</a></td><td>reinelt</td><td>1</td><td><span class='deletions'>-1</span>/<span class='insertions'>+9</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
fixed a compiler issue with drv_Image.c (thanks to Frank Stratmann)

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@446 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-29 15:53:28 +0000'>2004-05-29</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugin_ppp.c?id=c17304852de34a6be81d931923dd9e21c637ba95&amp;follow=1'>[lcd4linux @ 2004-05-29 15:53:28 by reinelt]</a></td><td>reinelt</td><td>3</td><td><span class='deletions'>-9</span>/<span class='insertions'>+25</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
M50530: reset parport signals on exit
plugin_ppp: ppp() has two parameters, not three
lcd4linux.conf.sample: diskstats() corrected

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@445 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-29 01:07:56 +0000'>2004-05-29</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugin_diskstats.c?id=927530dfa14e1d35abd5a564a730f4fcf598a416&amp;follow=1'>[lcd4linux @ 2004-05-29 01:07:56 by reinelt]</a></td><td>reinelt</td><td>2</td><td><span class='deletions'>-21</span>/<span class='insertions'>+25</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
bug in plugin_diskstats fixed

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@444 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-29 00:27:23 +0000'>2004-05-29</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugins.m4?id=4749def80d9a775c8d0791fe322322f5d1425c95&amp;follow=1'>[lcd4linux @ 2004-05-29 00:27:14 by reinelt]</a></td><td>reinelt</td><td>8</td><td><span class='deletions'>-11</span>/<span class='insertions'>+214</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
added plugin_diskstats.c

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@443 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2004-05-28 14:38:10 +0000'>2004-05-28</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/Status?id=ba5326cf8e6dd8051efadde4528e3aeb6e654fb2&amp;follow=1'>[lcd4linux @ 2004-05-28 14:38:10 by reinelt]</a></td><td>reinelt</td><td>2</td><td><span class='deletions'>-1</span>/<span class='insertions'>+41</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
Status and Changelog Update

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@442 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>