===== Get rid of your printer port adapter now! =====

{{:logo.4.gif}}

The [[http://www.harbaum.org/till/lcd2usb|LCD2USB]] is a cheap do-it-yourself interface to connect HD44780 based text lcd displays via USB. LCD2USB is cheap and consists of easy-to-obtain parts only. The 
interface has been tested with 2*16, 2*20, 4*20, 4*27 and 4*40 displays and supports software
adjustable contrast and backlight as well as dual controller displays (required for 4*27 and 4*40).

It is based upon the [[http://www.obdev.at/products/avrusb/index.html|AVR USB]] implementation. This
is a pure software implementation of the USB protocol for the Atmel AVR microcontroller series. 

The whole interface incl. the hardware layout is under a GPL like license. This means that you
can take these schematics and use it as a basis for your own interface e.g. for a graphic LCD.

===== Display Section =====

<code>
Display <name> {
    Driver     'LCD2USB'
    Size       '<string>'
    Bus        '<string>'
    Device     '<string>'
    Contrast   <number>
    Brightness <number>
    Icons      <number>
    asc255bug  <0|1>
}
</code>


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===== Parameters =====

|Driver|'LCD2USB'|
|Size|<column>x<rows> example '16x2'|
|Bus|Bus name as displayed during USB scan (e.g. '003'). Only required when using multiple LCD2USB interfaces.|
|Device|Device name as displayed during USB scan (e.g. '004'). Only required when using multiple LCD2USB interfaces.|
|Contrast|initial contrast value, 0..255 (useful range depends on the display)|
|Brightness|initial backlight brightness, 0..255|
|Icons|Number of user-defined chars reserved for Icons (default: 0)|
|asc255bug|set to 1 if you don't get solid blocks in bars, but an a wire character|

----

===== Examples =====

<code>
Display LCD2USB {
    Driver     'LCD2USB'
    Bus        '003'
    Device     '004'
    Contrast   250
    Brightness 200
    Icons      1
}
</code>


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===== Plugins =====

The driver provides the following functions:

|LCD::contrast(n)|set contrast to n (0..255, range depends on the display)|
|LCD::brightness(n)|set backlight brightness (0..255)|

----

===== Buttons =====

The driver includes routines to read the button states, but at the moment 
(lcd4linux-0.10.1-CVS) there is no support for buttons in the framework. 

According to [[https://ssl.bulix.org/projects/lcd4linux/wiki/widget_keypad]] the keypad widget of LCD4Linux-0.10.1-RC1 supports the buttons of LCD2USB.

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