Please recommend a VGA to parallel LCD board or IC - Page 1
Forum section: electronics / projects

author: DC1MC
author_rank: Super Contributor
timestamp: December 03, 2020, 06:48:27 pm
content: Hello everybody,In my quest of replacing the CRT displays on some TE with LCD, I need to get some of these VGA to LCD adapter boards (or maybe the just the IC) that can be configured regarding the number of lines/pixels that can be skipped, timing and other parameters, because getting 4:3 aspect LCDs in 6-9" range with VGA resolution is almost impossible nowadays for an acceptable price, so I may need to configure a "window" into a larger or higher resolution LCD.Any suggestion is highly appreciated, especially ready made adapter boards, except for FPGA solutions "from scratch" because I have neither the knowledge, or the workflow to build FPGA digital design applications.Many thanks,DC1MC

author: Benta
author_rank: Super Contributor
timestamp: December 03, 2020, 07:03:31 pm
content: VGA to HDMI adapters exist (though a bit rare), but are not cheap.https://www.conrad.de/de/p/delock-vga-hdmi-adapter-1x-vga-stecker-1x-hdmi-buchse-schwarz-25-00-cm-1410382.html

author: DC1MC
author_rank: Super Contributor
timestamp: December 03, 2020, 07:42:51 pm
content: @Benta - thanks for your reply, but I'm not looking for anything like this, I'm looking for a driver board (or IC) that is capable to drive a LCD panel with either TTL parallel inputs or LVDS (not MIPI-DSI) using signals from the VGA connector that many test equipments have.That is because I want to replace the CRT for the devices that have a VGA or raster display, the vectorial ones are a totally different story.So far, after some search the most popular seem to be Realtek RTD2660/RTD2662 that seem to be in a lot of low cost driver boards as well as available as individual ICs.The chip is pretty interesting, it has a lot of interfacing possibilities and the embedded 8051 core allows for OSD and other programmable stuff.For the benefit of other people that may look for something similar, I'm attaching the datasheet and links to the programming interface (multiple options) and to some castrated but, useful SDK.SDK:https://github.com/danyaPostfactum/RTD2660.gitProgramming via i2c:https://github.com/ghent360/RTD-2660-ProgrammerI would LOVE to get the original SDK and examples from Realtek, but because I'm not Chinese, it will most likely not happen.Please if you know of other resources related to this chip or other similar chips post them here or PM if they are "hot".Cheers,DC1MCEDIT: Datasheet is too large, PM me if you want it but is allover the net.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 03, 2020, 07:59:24 pm
content: I can't "recommend" anything in the sense of a solution that I know works, but:https://www.ebay.ca/itm/VGA-To-LVDS-LCD-Controller-Board-for-6-5inch-TFT-G065VN01-V2-640X480-LED-Screen/183748761548?hash=item2ac84797cc:g:SvMAAOSwLi1cmdXoOf course this might not come with the amount of control you want.VGA to HDMI seems cheap and cheerfulhttps://www.ebay.ca/itm/VGA-to-HDMI-Adapter-with-Audio-Male-VGA-to-Female-HDMI-Converter-Laptop-to-TV/273489746206?epid=9031281119but who knows how it will work in reality?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 03, 2020, 08:00:47 pm
content: Quote from: Benta on December 03, 2020, 07:03:31 pmSimilar things are available on ebay for about £6. I use one on my Keysight MSOX scope.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 03, 2020, 08:03:14 pm
content: Might be worth talking to a company that supplies to the signage market, as they often combine panels and converter boards to build monitors into custom enclosures

author: DC1MC
author_rank: Super Contributor
timestamp: December 03, 2020, 08:28:50 pm
content: OK, I was really not able to make myself clear, I really don't care to connect an external monitor using the VGA connector of the instrument, I know that VGA to HDMI adapters are a dime a dozen.Once more: I want to kick out the whole CRT assembly from some TE, because of unobtanium/damaged CRT and replace it with a "RAW" LCD panel, with either TTL parallel or LVDS inputs ("dumb" LVDS, not MIPI-DSI).Because the available LCD panels have either a different aspect ratio or resolution, I need to have a driver board where I can control the full graphical pipeline, scaler, timing, etc.So far it seem that the most affordable chip that can be found either as an IC or a driver board is Realtek RTD2662/RTD2660 series, the difference is 2662 has the HDMI encryption supported, that I don't care, otherwise are equivalent.There are a couple of others that I've found, one form MStar Technologies and another from an obscure company, but the firmware and datasheets are really hard to find.So if you have some application notes or other interesting material about RTD2660 or cheap ready adapters with VGA input please let me know. Information about other chips is welcome, but at this stage it will take a wonder to show up.Cheers,DC1MC

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 03, 2020, 08:43:55 pm
content: Chrontel CH7034 looks like it might be of interesthttp://www.chrontel.com/product/detail/36

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 03, 2020, 08:56:19 pm
content: This board is cheap enough that it might be worth investigatingA buttload of firmware versions in the linked archive, but as they say "no instructions on how to burn.." If you're lucky the FW could be stored in external SPI flashhttps://uk.banggood.com/Universal-LCD-Display-Driver-Board-PS2PS3xbox360-HD-AV-VGA-p-976957.html

author: DC1MC
author_rank: Super Contributor
timestamp: December 03, 2020, 09:03:47 pm
content: Quote from: mikeselectricstuff on December 03, 2020, 08:43:55 pmIt may, if they will have a Reference Manual or Programmer Manual, or similar. But they don't

author: DC1MC
author_rank: Super Contributor
timestamp: December 03, 2020, 09:09:32 pm
content: Quote from: mikeselectricstuff on December 03, 2020, 08:56:19 pmThisseemsto be one of the many RTL2660 available boards on an acceptable price, of course it's difficult to be 100% sure because of the disgusting habit of the sellers to provide giant pictures with huge white space and the highest possible JPEG compression, and not to forget, a smear of shit over the chip info. the firmware versions are just useful for reversing, as I need fine grained control to slice and dice the LCD surface, but I've got some complete manual and some firmware sources.In any case thank you,DC1MC

author: DC1MC
author_rank: Super Contributor
timestamp: December 03, 2020, 09:12:45 pm
content: Some more technical information in the beautiful language of Puskin:http://pccar.ru/showthread.php?t=22851Including the LCD connector pinout and other important info.Holly crap, an open hardware project:http://openrtd2662.ru/DC1MC

author: Miti
author_rank: Super Contributor
timestamp: December 04, 2020, 02:48:15 am
content: Quote from: DC1MC on December 03, 2020, 08:28:50 pmThat would make a fun FPGA project.

author: DC1MC
author_rank: Super Contributor
timestamp: December 04, 2020, 07:04:42 am
content: Quote from: Miti on December 04, 2020, 02:48:15 amAbsolutely, if someone would do such a board at an acceptable price I'll definitely get me some of them, but looking at what the Realtek chip can do, I realize that hardwarewise it will be almost impossible to do what that 5EUR chip does for less than 100EUR, there's practically no low cost FPGA that can have composite, VGA analogue and HDMI inputs, not talking about the outputs at all.The power of specialized silicon is way too big here.DC1MC

author: Miti
author_rank: Super Contributor
timestamp: December 04, 2020, 11:59:25 am
content: From what I understand you want to display a 4:3 image on a 16:9 panel for example? Can that Realtek chip do that? You’d need a buffer for that.

author: DC1MC
author_rank: Super Contributor
timestamp: December 04, 2020, 12:25:32 pm
content: Quote from: Miti on December 04, 2020, 11:59:25 amIt seem that it can, it had a scaler engine according to the datasheet, and you don't need that much of a buffer for a simple rescaler, just few lines in the pipeline, in any case, I won't bother with the scaler if the the aspect ratio of the panel is not 4:3, I will just display my original image with some offset necessary to frame it correctly if I'll use a larger panel with higher resolution and only show a portion of it where the old display was.

author: Miti
author_rank: Super Contributor
timestamp: December 04, 2020, 06:02:29 pm
content: That’s an interesting board. I have few wide LVDS LCDs that I’d like to play with. Did you figure out how to program it? Someone in the review says that an FTDI board is needed but he doesn’t give details. Can you brick this chip if using the wrong binary?Regarding the offset, you may be limited in the number of pixels that you can offset the image.

author: DC1MC
author_rank: Super Contributor
timestamp: December 04, 2020, 08:25:33 pm
content: Quote from: Miti on December 04, 2020, 06:02:29 pmI have a full data sheet, a number of SDKs with source code for the Keil C51 compiler, many examples of OSD fonts.The chip needs an SPI EEPROM, it can't be bricked and it doesn't have any eFuses or encrypted crap, so is always recoverable.The EEPROM programming can be done via I2C, including reading the original fw. Any I2C master is OK, the cool kids use an old Linux laptop with VGA interface, because the I2C bus is present there for monitor DDI and EDID. Coolest way to program it ever.The Chinese, parentless as we know them, use some obfuscated binaries (.ggf) for loading firmware, but even so, there is a free utility that can use these blobs.I have ordered a number of boards with 2660 and 2662, because I'm thinking of "hijacking% the OSD and make it doind cool stuff like displaying the temperature, some voltages and so on over the image.This is a very versatile chip and I just cant wait to get it.The most cost effective board to play with, is IMHO this one:https://www.ebay.de/itm/HDMI-VGA-AV-Control-Driver-Board-8-inch-HE080IA-01D-1024-768-IPS-LCD-Display/353127261573There are a lot of sellers for this configuration, the 8" display is 4:3 and it will definitely fit nicely to my firstvictimexperiment subject: a Tektronix AWG520 on its way to me. Also in many other TE with CRT displays and VGA interface.I'm thinking to make an OSS/OHW project here on eevblog if there is enough interest, but I'm not holing my breath.Cheers,DC1MC

author: Miti
author_rank: Super Contributor
timestamp: December 05, 2020, 03:50:07 pm
content: Quote from: DC1MC on December 04, 2020, 08:25:33 pmI hope you get the correct chip. I ordered two LCD modules that showed one chip and I received a different one.Quote from: DC1MC on December 04, 2020, 08:25:33 pmThe one from Banggood is easier to connect to any LVDS LCD, it has a pin header.

author: DC1MC
author_rank: Super Contributor
timestamp: December 05, 2020, 07:31:42 pm
content: @Miti: In the epay pictures of the 8" display with 2660 driver board, the chip is marked clearly, if somehow got replaced, open dispute and good bye, the 2662 are from a German seller and he put the actual pictures.Regarding the connectors is meh, I'll anyway have to do adapters.I'm still reading the full datasheet, the thing is a MONSTER, no way in hell one can replicate this with low cost FPGA. All analogue composite modes, PAL/SECAM/NTSC, VGA analogue, HDMI and so much more, not to mention scalers and colour correction and auto detection of the formats, I'm truly amazed of what stuff we are missing because they've decided to hold the information until now.I actually could not think of many other things to be done with a LCD that could not be covered somehow with this chip. And for the people that don't like to tinker with programming, there are a gadzillion of premade firmwares for almost all the LCDs in the universe, at least the non MIPI ones.Because I cant attach the full datasheet here I'm attaching a link to it and encourage everyone that likes to play with LCD panels to have a look, you will be amazed:http://aitendo3.sakura.ne.jp/aitendo_data/product_img/lcd_controller/Xs/RTD2660.jsp.pdfAlso Adafruit sells something similar, but long are gone real schematics, just some Chinese PDF with missing info, but still better than nothing:https://learn.adafruit.com/hdmi-uberguide/rtd2660-hdmi-vga-ntsc-pal-driver-boardCheers,DC1MC

author: DC1MC
author_rank: Super Contributor
timestamp: December 05, 2020, 07:37:51 pm
content: One more link with the programming tools and extra info:http://www.mattmillman.com/info/lcd/rovatools/

author: Tantratron
author_rank: Frequent Contributor
timestamp: October 28, 2024, 08:23:12 am
content: Quote from: DC1MC on December 03, 2020, 08:28:50 pmHello DC1MC, I'm glad to find this thread where myself I'm trying to do the same thing, in particular to retrofit Advantest R3261/R3361/R3265/R3365/R3271/R3371 spectrum analyzer CRT's to a LCD kit.In my case, the RGBS output stream flow is 15 KHz interlaced but I see that either RTD2660 or MST703 can actually de-interlace then I guess generate a proper scaled 4x3 resolution to drive LCD wether TTL or LVDS. There is hardware hack trick on the spectrum analyzer CPU board near the GCPU which makes possible to colorize the CRT display so the key problem is really transforming the RGBS 4 channels (each 1 bit) into a viable VGA then LCD format.Have you done any progress since your last post circa 2020, any hope to obtain say the source code from Realtek or Mstar to build and compile specific application ?I see some firmware programmers sold on eBay or AliExpress but it seems they only flash or write a firmware file, the challenge being how to create the firmware for a give application.Thanks, Albert

author: coromonadalix
author_rank: Super Contributor
timestamp: October 28, 2024, 02:51:37 pm
content: maybe theses for the 2660 or others ?https://github.com/raylabpro/RTD2660_PCB800099https://github.com/ghent360/RTD-2660-Programmer/blob/master/README.mdhttps://www.mattmillman.com/info/lcd/rovatools/https://www.mattmillman.com/info/lcd/rovaedit-firmware-editor-for-r-rm-series-lcd-controllers/https://www.jagdroid.org/video-board-programming-and-modification/

author: DC1MC
author_rank: Super Contributor
timestamp: October 29, 2024, 10:19:54 pm
content: Hi Albert, I have collected all the necessary information, as mush as it is possible for some non-Chinese private person, there is absolutely no chance to get anything from Realtek. Even so, I have collected a lot of source code and settings for a multitude of input and LCD panels.The links that @coromonadalix posted are very useful as well, I wish I would have had them at the time.In the end the RTD chip has an 8051 compatible MCU that manages the video pipelines and settings and is really not an big issue to understand the flow by piecing information from the source code, datasheet and configuration files.I've got a number of boards with different LCD panels and input configurations and they responded very well to changes.Actually the biggest problem is the build environment needs a fully featured Keil uVision MCS-51 development environment, that since being acquired by ARM become prohibitively expensive. There seem to be some non-commercial ways to get a license, maybe nowadays one can get a community edition or such that still has the full optimizer and code size active, including banking (that is needed for the chip).I've managed at the time to get a temporary demo license but fully featured and compiled some of the projects found in source on different sites, the results were pretty good and I can guarantee that you'll be able to process the input signal put out by the instrument.In the meantime I've become pretty sick and this, combined with other personal problems, made me lose most of the interest for TEA and just become a more or less a passive reader of the forum. Just waiting for the moment to search for someone wiling to come to Mannheim and load half of a van with different parts, projects and instruments available for a pittance, before they will be sold for scrap by estate liquidators.But to not end in a depressing mood, if you're seriously willing to do this project, able to get a fully featured Keil uVision MCS-51, get one or more of the boards that I've mentioned in the previous posts and spend a large number of hours fiddling with the video pipeline settings I may be able to assist you in this matter.BTW, as a side note, the "programmers" are different implementations of an I2C master with different types of bit-banging, because the "standard" SDK includes a cool I2C device implementation that is used to program the EDID and to upgrade the firmware because, this is how the VGA and even HDMI expose the monitor modes to the graphics card. Of course this is not needed for your project, but it was funny to see how each and every version of the SDK that leaked had this changed to make it incompatible with anything else except their proprietary SW.Cheers,DC1MC

author: Tantratron
author_rank: Frequent Contributor
timestamp: November 01, 2024, 08:23:42 am
content: Hi DC1MC,Would you have a main folder or github project where you have stored all your findings plus the software because when I look on Github, few members have done partially so there is no global view picture.For the moment, I've three different LCD (5.6" by Innolux, 5.7" by AUO and 6.5" by AUO, the latter is LVDS whereas the first two are TTL driven) then 3 drivers, one based on RTD2660, the other based on the MST703 and the last based on RTD2280. I should have soon a USB Adafruit FT232H Breakout to pursue my learning curve but still have not decided which programmer I'd purchase or if some software can compiled in C or Python to directly program through the Adafruit connected to the VGA specific I2C pins.Now the billion dollar question is how to cost effective and ease generate and create specific firmware or how can we read or manipulate say an existing firmware file to change resolution, pin output adapter and in my project the de-interlacing.P.S. It seems less public ressource exist with the MST703 chip (Mstar) versus the RTD2660 chip (Realtek) so I might drop the MST703 quest.Warm regards, Albert