Need help from LCD gurus... 26 pin 7 inch TFT, drive from prop or use a driver chip?

rwgast_logicdesign

So rooting around through boxes I found an old raffle prize..... A multimedia picture frame! I turned it on and hit menu and it didnt seem to work, except the back light. I am not sure if the TFT is the problem or something else. It uses a "Zoran" CPU some DRAM and that's about it. The cool thing is LCD module (TFT and backlight) is available on ali baba and there are data sheets so it is common. The LCD is an InnoLux ATO70TN90, the datasheet is hosted on AdaFruit i am not sure why... I can not find a product using it. At first seeing it on AdaFruit I thought score Arduino Library lol.

Anyways I have no idea how to directly drive an LCD even looking at the data sheet..... My first question is could the prop directly drive this, and if so how well? Secondly would this interface to a more popular driver chip? If they answer to that is yes how would one go about figuring out compatibility? Im sorry I have never used a TFT LCD before only things like 16x2's with there common chip interface.....

I am working on a HUGE upgrade to the RTL-SDR dongle...basically making it in to a stand alone radio with DC-3ghz and tons of filters! I would like a cheap 5 inch plus screen such as this one to display menu's frequency information and FFT's but I am LCD clueless especially when you have a panel without a driver chip!

kwinn

Based on the data sheet I think the prop could drive it directly, but would not have enough memory to take advantage of the 800 x 480 pixel resolution or the 24 bits of RGB color. It might be possible to use it for what you want using a dedicated prop running a tile driver but the hardware and software would be pretty big projects.

rwgast_logicdesign

Well like I said Im no LCD guru I dont even know how to drive an LCD directly. If I were to learn I think I would choose an LCD that has examples out there and projects behind it. I have messed around with a few small 2.2 inch LCD modules with controller chips... this seems easy enough to understand without a canned library. Can you recommend a an LCD driver chip, and maybe go over the parametrics of finding one to match an LCD? Im building a 160mz cmos VFO/sweeping sine wave oscillator up to 40mhz in a copper box with sma connectors and an encoder. I really wanted to use my 2.2 inch touch LCD on this project. And on the radio itself I just want a bigger screen and im hoping this screen will work out because I don't have money to blow on some fancy Adafruit screen or any 7 inch LCD with controller,

I was really wondering if the prop could drive it bear because like I said the picture frame doesnt seem to work and I wanted a quick dirty way just to test the LCD, but im not even sure how the signaling works. I read the data sheet but for the first time I just felt stupid.... btw IDK how to do NTSC signaling either I just use library's for that stuff, keeping the V and H synced seems like more black magic than RF!!! Originally before I found out the frame didnt do much besides turn the back light on I would use a scope and LA on it to learn..... but thats not going to happen now.

Rayman

That display is somewhat similar to the Newhaven 5" LCDs that I've worked with.
The 4.3" Newhaven adapter for P1 that I made would also work with their 5" screen although it couldn't drive the backlight to full power.

Couple things I see there are that you'll need a lot of backlight power with 7" screen.
Also, you need to provide VGL and VGH voltages. Some LCDs include circuitry for this, some don't.

So, I think you could make it work, but it would take some effort...

An easier way might be to buy a display with an SSD1963 driver chip. I have Spin code on my website that can talk to that driver chip. I've seen boards around Ebay and Newhaven with that driver chip and the LCD and backlight all there.

kwinn

If all you wanted to do is use the propeller for go/no go testing you might be able to drive it directly from the propeller to produce a color bar pattern across the screen. The CLKIN (aka DCLK) would have to be generated by a counter to get the 26 - 47MHz frequency signal that is needed, and the video generator or a fast PASM pasm loop could be used to output the video data. That leaves the VGL and VGH voltages and a few other timings to work out.

It could be done, but imho it would require more time and effort than it is worth unless you are doing it as a learning project or plan to build displays as part of equipment to sell.

rwgast_logicdesign

Well I have a 5 output VFO I built (For RF, and filter seeps) two will drive 8khz though 200mhz Square waves. the other two generate 12.5mhz/square/triangle and lastly a sweeping 50mhz sine wave. Id have to read the data sheet but im sure the voltages shouldn't be that hard, if nothing else I can use hot air there voltage drivers off the board. The real issue for me is writing the test block code, can you use any prop library for this this is where I stumble i don't know anything about driving an LCD with ought controller chip!

I will check out the SSD1936 this is what I was hoping to hear.... but I thought they only supported 40 pin LCD's adafruit sells a board with SSD controller that will drive any large tablet screen but it says 40 pin

rwgast_logicdesign

Ok so searching ebay for SSD1963 I found some stuff but im confused details are vague, this LCD has a 26pin ribbon the socket for this is 40 pins...

ebay.com/itm/Screen-PCB-Adapter-Build-in-SSD1963-4-3-TFT-LCD-Module-Display-Touch-Panel-/310862159032?hash=item4860d41cb8:g:FUYAAMXQeKNTLQAr

If I could afford it this would probably be the better solution the screen is touch and im sure its better quality the is an old frame!

http://www.ebay.com/itm/7-7-inch-TFT-LCD-Module-Display-w-Multi-Capacitive-Touch-Panel-Screen-SSD1963-/301065867282?hash=item4618ec9012:g:a1gAAOxyRhBS0QoR

Part of the issue is the SDR im working on I want to be able to easily re assemble myself, and publish it open source using most manhattan friendly style parts that can be cheap. Till now the 2-5ghz converter was the only chip the would need either a custom pcb or at least a dip adapter. I wanted the LCD to be cheap and easily able to source. The one in the frame was just for prototyping ... I guess I need to do my research. Are there any chips that will drive a laptop LCD? Everyone can sourve those for free just about.