Iš senų prietaisų (daugiausiai iš dauginimo aparatų) prisirankiojau grafinių LCD ekranų. Tai paprastai monochromatiniai LCD ekranai be kontrolerių. Tokiems ekranams reikia dinamiškai perdavinėti vaizdą iš kontrolerio. Dažniausiai tai būna SED1351 ar panašūs grafiniai kontroleriai. Gal pačio SED’o datasheetą gal ir galima rasti, tačiau patys ekranai būna visai nesurandami. Pasinaudojęs veikiančia plokšte pabandysiu išaiškinti keletą LCD ekraniukų.
Beja, tokiem ekraniukams dažnai reikia neigiamos įtampos šaltinio. Pagrindinė logika maitinama iš 5V.
LCD ekranas pavadintas “EDMMPU3BDF“, 320×240 monochromatinis grafinis ekranas, baltai mėlynas, dažnai buna su touch screen.
1. screen_on (0-off, 5V- on)
2. nc
3. VSync
4. HSync
5. pixel clock
6. Vcc, +5V
7. GND
8. Vee, -25V (tas pats kas pin 13)
9. D3
10. D2
11. D1
12. D0
13. Vee, -25V
14. kontrastas, ~-18V
Standartinis protokolas pavaizduotas grafiškai (oscilogramos):
Didelis paveiksliukas spausdinimui ir analizavimui.
WF signalas naudojamas kai kuriose LCD panelėse generuoti kintamą įtampą per LCD kristalus, kad apsaugoti metalizaciją nuo erozijos. Ne visi LCD ekranai naudoja šį signalą. Ten paprasčiausias loginis signalas kuris keičiasi kas kiekvieną kadrą.
Gal po ranka turi kokią paprastą ir pigią keitiklio 5V -> -14..20V schemutę?
Nu šitas LCD moduliams tinka:
http://www.vabolis.lt/2006/02/28/dcdc-keitiklis-lcd-moduliui/
Dar kažkur yra impulsinių stabilizatorių schemos. Ten lengvai galima pasidaryti tiek teigiamas, tiek neigiamas įtampas.
Ačiū. Visai buvau pamiršęs apie šią schemą.
Sujunk nuosekliai dvi ICL7660 tai dar ir isoriniu komponentu sutaupysi
TD018THEJ6 (1.8, 128×160 TFT LCD, 20 pins) pinout:
1-LED-K(-)
2-LED-A(+)
3-GND
4-VCC (3.3V)
5-NC
6-NC
7-CSB, /CE
8-RESB, RST
9-D/C, A0
10-/WR
11-/RD
12-D7
13-D6
14-D5
15-D4
16-D3
17-D2
18-D1
19-D0
20-GND
Eksperimentuojant su kitu LCD pastebėjau, kad labai svarbu, kad VSYNC metu praeitu HSYNC impulsas. Matyt VSYNC “patvirtinamas” HSYNC impulsu.
Maybe my question sounds stupid to you but do you know how i can create one kind of interface to use a TD018THEJ6 like a “kind of” VGA monitor, or How i can connect a TD018THEJ6 panel to a PC using SVHS or VGA output. I was thinking on it to create a mini projector.
It is very simple and at same time quite complicated… VGA is analogue, and this monitor is digital. 🙂
We need to get one interesting chip: pixel clock regenerator. Many years ago I ordered such chip from Allegro. Or maybe it is possible to get pixel clock from other part of VGA chip.
Now we have pixel clock, HS, VS. As LCD is monochromatic and small, we need to reduce pixel clock by 2 or more, also, we need to use less lines of the screen.
Now select analogue sygnal and select level with comparator to set contrast.
Now sample 4 times this sygnal using pixel clock to some trigger and send 4 bits to LCD.
🙂
Great idea. I think that tft TD018THEJ6 is a colored display. I found the Motorola MC44145D Pixel Clock Generator/Sync Separator circuit.
I am thinkig on it… one kind of VGA interface (external)
VGA Output -> Vga Connector -> MC44145D -> TFT
I understand the circuit logic, but i really need a help to create some kind of schematics to create this.
This mini monitor will be used inside an old Slide Projector look like system with fresnel lens and led illuminating. This “projector” will be used in another projects.
In general lines is that, one mini VGA monitor but How i can connect this? May i can use an LCD Monitor Circuit (A Samsung monitor for example).
… better find small 15″ color LCD monitor and use it without problems. You may find it with burn out lamps cheaply.
I completelly understand you but I really need to “made” a small solution… more or less 2 or 3″.
Try to find VERY old 15″ LCD. They are made with several chips and no LVDS output, but plain digital RGB- 18 or 24 bits. And all pixel clock stuff inside. Only need to divide pixel clock by 2 or 4 (same with hsync) and you can connect your LCD.
will this LCD work without Vee (pin 8 and pin 13) and contrast (pin 14) conected? I have 3 displays of this model and i would like to test them before building an inverter.
Thank’s
No, the screen will be black. Contrast pin is draining very low current, so only small trimmer is good for voltage divider.
Thank you very much for your answer.
But what is the function of VEE? Does it need negative voltage (with respect to GND). -25V is this critical? DC or AC? And on contrast as well: -18V… why not +18? DC or AC?
P.S. I really need this info because I couldn’t find a datasheet anywhere and I’m trying to build a little project around this LCD.
Vee is negative suply for liquid crystal. New LCD screens have internal capacitive negative bias suply. Old one need external. I don’t think it is very critical, but it must be negative. I collected this data from working unit. It is DC, but very low current. Original screens use small 2x1cm DC/DC convertors from Rohm.
I am using “~” symbol to show “about”, not AC.
Thank you, it’s all clear now. One last question: which one is pin 1?
You can find GND… 🙂
Hi,
I got two that’s same displays 🙂 and I hook up one of them to SED1330 (salvaged from some cash register or something like that…) + AVR ATMega32 (AVR-GCC) and this are my results 🙂 :
And I want to say “thank you” for sharing pinout for this lcd panel!
btw. You have interesting stuff on your site 🙂
Ups… links got chopped -_- :
http://imageshack.us/photo/my-images/594/sed1330edmmpu3bdflcd.jpg/
http://imageshack.us/photo/my-images/84/sed1330edmmpu3bdf.jpg/
Sorry for double-comment 🙂