Emerging display ew32f00bmw

Forum 2005-2010 (read only) Hardware Interfacing
1

I recently went to my favorite (and only nearby) electronics surplus store and came across a 320x240dot lcd. Excitedly I paid the 8.95 for it thinking "Oh boy, this will be fun to play with on the arduino and I'm sure I will be able to figure out the pinouts thanks to the handy dandy schematics that come with it!" Boy was I wrong. After searching forums, schematic sites and the like I seem to be unable to figure out where to even start with my project.

The first stumbling block really came while reading the schematic and I realized that I have no idea what I am doing. Being the determined fool that I am I then set about doing as much research as possible. I have found libraries and wiring diagrams for all sorts of different lcd's and oleds but nothing seemed to have the same pin symbols as what I was looking at leaving me a bit confused.

http://vision-opto.com/EW32F00%20320X240.pdf

I guess the best place for me to get started is really how to reconcile the symbols I have with the symbols everywhere else. So far I've managed to associate these

| Schematic | best guess

  1. FLM Clock?
  2. CL1
  3. CL2
  4. M
  5. VO contrast?
  6. VDD 5v
  7. VSS,VLSS ground
  8. VEE
  9. D0
  10. D1
  11. D2
  12. D3
  13. DISPOFF
  14. VLED Backlight +

I know the D0-3 are the data lines but every example I've come across has 8 lines and most only use the lower 4.

I realize that I havent exactly gotten very far and that I am in at least up to my chin if not over my head but what better way to learn to swim then almost drowning.

Any help will be greatly appreciated.

http://cn.fpdisplay.com/trade/photo/20070205092622_middle.jpg
image of actual screen

2

Nobody seems to have replied, and I have one of these displays. It will be eventually interfaced to an ATMEGA processor. I've gotten a Optrex F51176 display interfaced to an ATMEGA644 or an ATMEGA2560.

The bottom line is that this display needs +5 volts, -27 volts (maximum, measured to ground), and drive signals. It's faking being a standard TV monitor, which means that it needs (effectively) vertical and horizontal pulses, as long as data and a clock to go with it.

While you CAN design hardware to do this (I've gotten a CPLD design that is starting to work with windowing and color bars), the easiest way is to use a commercially available LCD controller chip.

I am currently using the Epson S1D13706 chip, which has 80K on board memory and provides all the driving signals needed. Note that on this display, you need to go to a B&W mode with only 4 bits of data, so you are mapping one bit per pixel. No gray scales allowed except for dithering.

You can easily find the application notes, and you want to look at the interface notes as well. The one that works for me is the 8 bit programmed I/O mode, which is a generic interface. IIRC, the chip has an interface mode that allows you to use an external clock, then use programmed I/O to get the display chip running.

You might also want to check out the S1D13500? chip which is optimized for B&W displays.

The bad news is that the chips are in a TQFP-100 package with 0.5mm spacing. For breadboard purposes, you can use the 2x2 sized breadboard carrier from Schmartboard. That allows you to easily breadboard this chip.

For the -27 volt supply, I used a TL497 inverter chip with a 220uh miller inductor (2100) from Jameco Electronics. That will work, and does work for me.

This is not a "how to do it", but it's very possible to get this display up and running. According to the manufacturer, it's a 320 x 240 display, transmissive, LED backlight (a plus), STN display. Don't look for great contrast, but it should be easy to interface with the right chips. Runs off 5.0 volts, so you will need to run the processor at 3.3 volts (the epson chips run at 3.3 volts), then level convert up to 5.0 volts.

It will take more effort than you thought, though.

On the other hand, with the other display, I have an icon driven display that runs text and graphics applications, so it is possible.

Not a short project, though.

I just picked up two of them, wonder if it's the same store....

Harvey