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45 lines
1.9 KiB
Plaintext
45 lines
1.9 KiB
Plaintext
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This is the README file for the Crystalfontz display driver for lcd4linux
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This driver supports the 632/634 LCD-Modules from Crystalfontz, but should
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work for the 626 and 636 modules too. The 634 is a 20x4 character display,
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while the others only display 16x2. I've written the driver using a
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634 module.
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The driver understands the following configuration parameters:
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Display: any of 626, 632, 634 and 636.
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Port: serial device (i.e. ttyS0) the LCD module is connnected
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to.
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Speed: any of 1200, 2400, 9600 and 19200. By default, the driver
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uses 9600 which is the speed the LCD modules are hardwired
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at. If your module works at a different speed than 9600,
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use this parameter. Otherwise omit it (i.e. omit it when
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you have a 634).
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Backlight: controls the backlight brightness. Quote from 634.pdf from
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the Crystalfonts-Webserver[1]: "0=OFF 100=ON. Intermediate
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values vary the brightness. There are a total of 25 possible
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brightness levels."
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Contrast: controls the contrast settings. Quote[1]: "0=very light,
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100 = very dark. 50 is typical. There are a total of 25
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possible contrast levels."
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Known bugs:
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When you draw a bar over a previously drawn textfield, the white portion
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the bar will not erase the text. Only when the black portion of the bar
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has reached the full bar length, the text will be erased. I did not bother
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to implement that, since in lcd4linux, the whole display-screen is erased
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prior to switching to a different 'screen'. Implementing this feature would
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just add to program-overhead. Yes, you guessed it: I did not use the "bar"-
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command that comes with the LCD-module, but wrote my own instead.
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lcd4linux also supports "split-" or "dual-bars" (two bars in one segment),
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which are not available on the Crystalfontz firmware.
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[1] http://www.crystalfontz.com
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