Have you built a digital TFT controller?

bes51659 · 12-08-2006, 05:42 AM

I will build a controller for a digital 800x480 TFT-LCD. I want it to fit mechanically into my prebuilt box (BMW Bordmonitor) with connectors in the right place etc.

(Digital means CMOS (or TTL as most people say incorrectly) inputs.)

This board will have
- VGA->CMOS or possibly LVDS/DVI to CMOS.
- 750V converter for the backlight
- Common voltages
(- Some extra button electronics etc)

The common-voltages seem to be the problem.

The display is a Sharp LQ065Y5DG02.
http://members.chello.se/bengt-olof....318[1].pdf

If the bios of my MII12000 could be upgraded to handle 800x480 I would buy the board to get DVI or LVDS from it, but I've got no hope there anymore.

Q1 ) Have you done this? Got any app notes or schematics?
Q2 ) Do you know of a LVDS mobo with 480x800 resolution (been asked before, I know...)

Regards, B-O

parksgm · 12-08-2006, 08:13 AM

Wow. Although I certainly can't offer any help, good luck, as that's ambitious!

bes51659 · 12-10-2006, 03:37 AM

I've found a circuit that does RGB to digital. AD9883

Anyone used it or got a better alternative?

I would also like to get my hands on the pinout of the flexistrip connector from the screen to the house of my BMW Bordmonitor. Any tips? I've tried bimmerboard.

sensibull · 12-10-2006, 05:27 PM

I am also in need of a controller to send VGA to a CMOS-input Hitachi panel (9" diagonal, 800 x 480, model #TX23D12VM0CAA) that came out of a Toshiba portable DVD (sp-d2800).

spec sheet available here

Unfortunately the pins are different from your Sharp panel. I would still be greatly interested in your progress, though, so please update this thread as you procede.

bes51659 · 12-12-2006, 02:28 AM

A, I'm not alone :-)
Different yes, but it seems like you are a bit more fortunate than me as I cannot find any 'grey' V0, V3... voltages in your interface. Don't know if your sync signals can be created by 9883 without looking closer at that.
If you are buying some 9883 (might be difficult to get) please check with me if I need some too.
(Its great if all those old worn laps can get a second life...)

sensibull · 12-12-2006, 12:25 PM

Unfortunately, I am complete newbie at all of this, so I will not be much help. I did however discover the digikey sells a version of that board in single units, for $12. If building a board is something you think you will really pursue, I'd be happy to buy you a couple of these parts and send them to Sweden, in exchange for working on one for me.

Does this section of my spec sheet provide any additional, pertinent info on the sync signals?

From what little I understand, the DTMG (Display Timing Data) on pin 6 is where the sync signals need to go, and my panel may even be able to adjust them on its own (if that makes any sense)

bes51659 · 12-13-2006, 03:30 AM

Its great if we can help eachother out. You are fortunate not haveing to generate the gamma correction (Vx) voltages. I think you can use the 9883, but I don't know how much extra electronics you need apart from that. Hopefully a pcb can be made that works electronically as well as mechanically for both of us.

Your link did not work, what board is it that you've found?

I read the Hitachi spec before (your link) but it is more the timing chart (9.1) that has to be looked into as well as the 9883 spec. My sharp glass has not got a HSync and VSync. Its got 'gatedriver clocks', etc. Maybe they are the same. That has to be looked into.

I will get myself more and more familiar with the 9883 in the week to follow. And I will eventually make my own pcb. Problem right now is that I can't get hold of interface (connectors) on existing analog controller board.

If you want to follow my progress, look at http://members.chello.se/bengt-olof....rPCProject.htm

Remember, I've never done this before even if I have a past as electronics designer so don't get your hopes up too high :-)

sensibull · 12-13-2006, 06:51 AM

Sorry about the link. Looks like you have to restart your search with each new session at Digikey, but if you go to www.digikey.com and type in 9883 and Analog Devices, and then look at the Integrated Circuits, you will get a bunch of circuits, only one of which is in stock and sold in single units -- the AD9883ABSTZ-110-ND.

bes51659 · 12-14-2006, 11:52 AM

Thanks for info about AD9883. I saw that there was a evaluation board with it for 300$... Good ide to buy the part and make a pcb ourselves. A board prototype can be made at www.pcb-pool.com for a very reasonable price. I think we can make a board that fits us both as long as you do not have specific mechanical requirements. Have you got any thoughts on how to set contrast and brightness? I want to put in a photo device to get night-light. No contrast setting.

Lets buy all the parts at the same time.

Here's a heavy post, but I plan to edit it rather than write new posts. Too bad I cannot make tables...

----------------
Any pointers to cheap, easy to get hold of circuits are greatly appreciated!!
----------------
I have found one interesting reading at Epson. Well, interesting for me with Sharp panel. "Connecting to the Sharp HR-TFT Panels" with S1D13706.
----------------
I have found an interesting guide from Sharp. It explains that there are 3 different kind of digital LCD types. (Don’t bother about the LH79520 SOC)
http://document.sharpsma.com/files/L...nterfacing.pdf

STN, Super Twisted Nematic
TFT, Thin Film Transistor
HR-TFT, High Reflectiv TFT (Sharp)

YOUR HITACHI PANEL IS A TFT

It has a typical interface for that type of Panel with one exception. DTMG. A combined vertical and horizontal sync. Typical signal names for such a panel are:

RGB, 3colours x 6bits = 18 leads (Hitachi-> 12-14, 16-18,20-22, 24-26, 28-30, 32-34)
CK, Data sampling clock (Hitachi -> DCLK, dot clock, pin 38)(Sharp-> DATACK)
HSync, horizontal sync (Hitachi ->DTMG, Display timing data)
VSync, vertical sync(Hitachi ->DTMG, Display timing data)
(ENAB, Horizontal display position set signal. Enable)
(R/L, horizontal direction select signal)
(U/D, vertical direction select signal)
(V/Q, VGA or QVGA)
VCC, 3.3V (Hitachi -> VDD, 1-4)
GND, ground (Hitachi ->VSS, 7,9,11,15,19,23,27,31,36-37,39-40)

WHAT YOU NEED ARE
- 3.3V Power
- ADC (Synchronized analogue to digital converter inside AD9883)
- a 33M3Hz pixelclock (PLL inside AD9883),
- some logic to create the DTMG signal (it is quite possible this is done by the AD9883 too. It states to handle composite sync)
- backlight voltage generator that require 700V or so. (Max 2000V according to your spec).
- some way of configuring the 9883 I2C registers

MY SHARP DISPLAY IS A HR-TFT

RGB, 3colours x 6bits = 18 leads
V0-V9, (grayscale voltage standard. Sharp-> V0, V3, V5, V7, V9, V10)
CLS, (clock and sync. Similar to HSync)
PS, (Invers of CLS. Power Save)
DCLK, (Dot clock)
MOD, (Enable)
SPS, (VSynch. Start Panel Sync)
VDD, (13.6V)
VCC, (-11.7V)
VSS, (-15V)
VEE, (Square wave. DC -9V, “AC” 5V p-p)
VCOM, (Square wave. DC 1.4V, “AC” 5V p-p)
VSHA, (Analogue Power. 3.3V)
AGND, (Analogue ground)
VSHD, (Digital Power. 3.3V)
DGND, (Digital Ground)
LBR, (Horizontal direction select signal)
SPL, (Similar to HSync, Sampling start)
SPR, (Similar to HSynch, Sampling start)
LP, (HSynch. latch pulse)
U/L, vertical direction select signal

I NEED SAME AS YOU +
- grayscale voltages with switches. Maybe a Sharp IR3E203 or a LMC6009 (not at digikey..)
- more power

STANDARD LCD (just to be complete)

RGB, D0-D7, Display data
VDD (21-24V), VCC (3V3), VSS (GND)
DISP (Enable)
YD, (VSync)
LP, (HSync)
XCK, (clock)

sensibull · 12-14-2006, 03:36 PM

Don't mean to jump ship on you, but I don't think I will pursue this to the point of making my own board (or paying for a prototype). My need for a VGA input is a matter of convenience, not absolute necessity

However, I did happen upon this ebay listing today and wondered if perhaps these fellows haven't done the work already.

The only thing I am uncertain of is the support for a 800 x 480 resolution.

More info on their board can be found here. Apparently you can email them pictures of your LCD and they can let you know whether it will work.

Here is a picture of the board.

.

bes51659 · 12-15-2006, 03:45 PM

Don't worry. Quite the opposite, thanks for the pointer to this very interesting yahoo group!

sensibull · 12-16-2006, 07:22 AM

Quite welcome. Please update this thread if you find success, either with that ebay board or one you build yourself. I'm sure others will find it helpful as well...

bes51659 · 01-09-2007, 05:16 PM

Well. It is not easy to get hold of LCD's and drive electronics to it.

As mentioned I ordered a Sharp LCD panel but as an escape route I've bought a DL065A and its all over my desk now. That unit is the only one I've found that has a 480x800 6,5" (or small 7") LCD. Well, apart from the small 7" Au Optronix glass, also difficult to get hold off, and a complete unit for about $3000.

Turns out the DL065 contains that very same Sharp LCD I've ordered as part.

Ortopsy-> http://web.comhem.se/bengt-olof.swing/DL065A.htm

That makes the DL065A drive electronics highly interesting, but it contains electronics that I can't even find datasheets for! (Is it a requirement to be Chinese to be designer today?)

Now, since I've got the electronics of the DL065A I will use it. I will make same glue electronics but that will be very specific for my application.

Bye Bye thread, and hope your project is progressing nicely too, Sensibull.

galvitron · 10-18-2007, 07:35 PM

Any luck finding a controller for the Sharp LCD? I have found some sources for this LCD but dont know which controller to buy...

bes51659 · 03-25-2008, 09:09 AM

nop. I gave up and bought a CID 650 from cartft that I scraped for components.