Re: [lcd4linux] Displaytech 164A

[Thorsten G. <dl...@gm...>]

Hi again,

> I've fixed it. Sorry

No problem.

Ok, so you can try try following conf:

Display DT164A {
    Driver      'HD44780'
    Model       'generic'
    Bus         'parport'
    Port        '/dev/parport0'
    Controllers 1
    Bits        8
    UseBusy     1
    GPOs        0
    Backlight   0
    Size        '16x4'
    asc255bug   0
    Icons       8
    Wire {
        RW        'AUTOFD'
        RS        'INIT'
        ENABLE    'STROBE'
        BACKLIGHT 'GND'
        GPO       'GND'
        POWER     'GND'
    }
}

Widget Heartbeat {
    class 'Icon'
    speed 800
    Bitmap {
	Row1 '.....|.....'
	Row2 '.*.*.|.*.*.'
	Row3 '*****|*.*.*'
	Row4 '*****|*...*'
	Row5 '.***.|.*.*.'
	Row6 '.***.|.*.*.'
	Row7 '..*..|..*..'
	Row8 '.....|.....'
    }
}

Widget Test {
    class 'Text'
    expression '1234567890123456789012345678901234567890'
    width 40
    foreground 'ff0000ff'
}

Layout Default {
    Row1.Col1  'Test'
    Row4.Col16 'Heartbeat'
}

Display 'DT164A'
Layout 'Default'

If it is running you should have a Marquee-style 1234... in the first
line and a pumping heart in the lower right corner of your display.

Maybe you can try some things before:

Power your LCD with the 5V (no further connections) and tune the contrast
pot so that you can see a black bar in the first and third line. So you
can be sure to see something if the display is fed with data.

The "R/W" isn't really nescessary. To exclude some errors, you can
pull pin 5 (R/W) of the LCD to GND and set the wiring definition
in the conf to "RW 'GND'" and disable use of the busy flag by setting
"UseBusy 0". So the display is "write only" but depends on a good
timing (it should!). If the busy flag is enabled, the timing is done
a bit more efficient, but that's not really important yet.

Another thing:

Be aware not to burn your backlight pot! The datasheet says 280mA@4,2V
for the gn/ye backlight. So Rv=(5V-4,2V)/280mA=2,9R. That means about
224mW of power dissipation...

Good luck!

Regards, Thorsten