LCD PC info display software.

[Gary J. Tait]

Basically I have a couple HD44780 compatible LCD modules that are hard
wired for 4 bit mode (the lower 4 bits aren't available on the
connector)so 8 bit mode is not an option).

I want to use one for a PC info display (CPU/System/RAM/Network/Winamp
Temp/Fan/usage/titles).


I need software to directly use the LPT port, or code for an AT902313
micro for standard serial protocol, which software like CrystalFontz
uses.

 

[Mark Jones]

Gary J. Tait wrote:

Basically I have a couple HD44780 compatible LCD modules that are hard
wired for 4 bit mode (the lower 4 bits aren't available on the
connector)so 8 bit mode is not an option).

I want to use one for a PC info display (CPU/System/RAM/Network/Winamp
Temp/Fan/usage/titles).


I need software to directly use the LPT port, or code for an AT902313
micro for standard serial protocol, which software like CrystalFontz
uses.

The LPT has plenty of pins to output data directly to an LCD. If you
are planning on writing a PC application to collect all that info and
spit it out the LPT port, the skill in doing that dwarfs the micro's
complexity by probably an order of magnitude.

A resource I've been perusing lately is http://www.masm32.com/ -
masm32 is a "high-level" macro assembler which works a lot more like a
HLL than is immediately thought. Depending on parallel/serial access
routines (I have no idea yet of their use in MASM32) you might
consider MASM32 with a GUI front-end like
http://easycoder.org/English/ - which can help to make a really
nice-looking and full-featured Win32 app.

Back to hardware: if you can already write the application to send
the data to the LPT port, then all you need is a good datasheet for
connecting your LCD directly and sending the right order of bits. Six
leads are required: D0-4, E, R/S (and R/W if you ever plan on reading
data back from the LCD buffer, otherwise just pull it low.) I'm sure
we could find some generic info if you need it, the HD44780 spec is
pretty well-known.

It should be possible to have your AVR poll serial data over COM1 and
output this to LCD, but from other's experience timing/interrupts is
pretty tricky. You could try http://www.avrfreaks.net/ as someone most
likely has already made such a beast. I know several have done such
with PICs; if you can use a PIC instead, the JAL language includes
serial and LCD libraries. sourceforge.net/projects/jal/ and
http://groups.yahoo.com/group/jallist


-- "If necessity is the mother of invention, then is experimentation
the father?" MCJ 20041116