I was looking through my junk boxes,and came across a nice 320 x 240 pixel 5.7" mono LCD module. This uses a built in SED1335 type controller.
Being fed up with the doom and gloom regarding the Guruplug, and the looong wait for mine from NewIT, I thought I would try to use the display with my Sheevaplug to while away the hours.
I purchased a pre-programmed PIC based controller from MPI, (www.angelfire.com/electronic/micropakindustries/index.html
) and wired my LCD to the MPI S133X module.
The input to the controller is either normal serial or high speed ascii, up to 1.5Mhz @ ttl levels and the command set is vast! for example a command for drawing a XY graph is:-
Text Command for Graph is:- AxxxyyyLDhhhwwwGTT
meaning of parameters
Starting Location upper left hand corner: xxx=<000:639>, yyy=<000:255>
Grid Style: L=<0:7>
Pixel Type: D=<0:2>
Y-Axis Length: hhh=<000:255>
X-Axis Length; www=<000:639>
Graph Type: G=<0:2>
0= 1st Quadrant
1= 1st/4th Quad.
2= 1/2/3/4 Quad
# of Pixels/Tic: TT=<00-99>
Default: 10 pixs/Tic
I have attached a picture of a weather station display demo provided with the MPIS module, running on my display.
My next step is to make a connection to J6 or J7 in my Sheevaplug. Since this is 3.3V logic I need to level change to 5V to and from the PIC controller.
I do not want to use a usb to async connection, I would prefer to leave my USB port free, and I am itching to try the internal async port on the Sheevaplug.
To drive the display from the Plug software. all I need is a small python script. to initialise the serial port and display, down load the "fixed" items in the display and then move the variable items to the various windows in the background.
The controller also has circuitry for a touch screen and a keypad. I have found a suitable cheap 4 wire touch screen on Ebay, when I get this going then I can control and set up my applications using the touch screen. I am thinking of environmental control apps, solar hot water control and logging, and weather monitoring.
Of course these can be done solely by web interface, but its a bit of a pain to have to have a laptop or pc and monitor with you when you want to adjust the solar heat exchanger pump speed. or boot up a system to look at the temperature in the garden. (There is nothing to stop me running a web display anyway, as a matter of routine, to display on my domain)
I will keep you posted on progress.