Re: Raspberry Pi as an inexpensive embedded LCDproc server

Hi,

Am 18.08.2012 05:09, schrieb Ethan Dicks:
> [...]
> It's six GPIO wires from the R-Pi to an HD44780 LCD, and the rest is
> all software.  There's plenty of space and horsepower to run LCDd on
> the R-Pi.  It's probably not too much of a stretch to whip up (and
> share) design files to mount a 4x20 (or whatever is desired) in a
> laser-cut acrylic enclosure with the R-Pi.  At $35 for the
> network-enabled computer plus, say, another $10 or $15 for the
> enclosure, it seems reasonable to bring the entire project in (with
> PSU and LCD) for $80 or less.
> [...]

As you might know, the RPi can be connected to I2C-bus-slaves. I hooked
up a 40x4-LCD (2xHD44780) to the I2C-bus via the Philips PCF8574.
Backlight is not switchable but it has two EN-lines so we can talk to
both controllers correctly.

On my Atmel NGW100 I used lcdproc for the same schematic, on the RPi I
wrote my own little LCD-software using Qt4 (I planned to use the
Bitwizard I2C_LCD
(http://www.bitwizard.nl/catalog/product_info.php?cPath=34&products_id=85)
and would've needed to write a LCDd-driver for that. So I went with
custom software due to time constraints and switched to the 40x4 later).

Uses only 4 wires (GND, SDA, SCL and VCC) this way and update-rate is
decent.

LCDd's standard HD44780-driver supports this "connection-scheme" so
needs no further modifications.

Best regards,
	Jannis Achstetter