How do i convert rca signals into TFT LCD component signals like VDD VCC ect

[jpoopdog]

HI

I decided to strip down my old tevion portable dvd player, it was in the trailer going to the dump, so i figured why not, i might be able to get something for the inductors and the 7 inch lcd.

To my surprise, the panel which housed the lcd secreted a (en/de)coding chip which takes in the basic LCD signals, which it even listed on the board, being ignd vgh vee vcc vdd vin vss s-c gnd cvbs/y agnd sda scl, and it uses that on the board, as well as controlling the CFL inverter from the same board.

I realized, as i had previously desired to try running a tft from rca, that now, half the job has been already done for me!

If i can find a chip or module , or build one using arduino, i can at last make a small portable LCD Screen, which ive been wanting for my car, and equally also for another project, in which a portable monitor would be extremely helpful.

Anyway, does anyone know how i can convert standard RCA signals into those which my board will take?
Thanks.

 

[Sangoma]

I don't think you need to convert, just guessing looking at the connection names, you have voltage inputs, grounds, contrast and brightness and a composite video input.

The best thing would be a lot of searching for displays (most likely the same display is used by many) and circuits for the same or similar players or TVs

 

[jpoopdog]

i understand what you mean, however i am clueless here about what the pins do. What exactly is a composite video input?
Im hoping for some understanding as to how this works ontop of how to get my rca video in there, or are you saying it should work directly?

 

[4pyros]

Pull the board and look up the number on the big chip.

 

[jpoopdog]

ok, i got it, its cheertek

ct675c - LF
B5688700
640gmgab

however im having difficulty finding any results at all that mention that part number.

the best i could find was this description on a website which hosts the code to program the chip, but so far, no where, not even places actually SELLING these, can provide a datasheet .

here it is
Describe: Cheertek (Cheertek) LCD Driver IC (CT675) of the C51 source code, the code structure of clear, readable strong. The chip integrates the Video-Decoder, Scalar, T-con and LED Backlight Driver, can be driven 3.5 ~ 10.2 "analog/digital screen receiving the input signal CVBS/S-video/RGB/YCbCr/CCIR656. At present, the main applications of the program There are Portable DVD/Portable TV/Car TV/digital photo frame/video doorbell video products such as medium and small size.

However, i do think this means that it does directly take analogue video signals! Am i right? i hope i am.

 

[Sangoma]

cvbs is composite video

 

[jpoopdog]

this is good. However, now im stuck with the new problem of figuring out how to run this thing. i cant locate a datasheet for the whole module or the IC ANYWHERE, also my slow internet isnt helping much either.
Because of the large numbers of inductors all over the main board, it could be anything. How to i get the LCD running so it will accept a signal for testing? or how do i find out?

 

[Sangoma]

vss is your supply, vdd is your negative supply, gnd s are quite likely joined together, sca and scl sound like i2c lines, vgh looks like it is the backligh, and vee could be the contrast.

Just ideas, use as ideas and not definite connections

 

[Bolbol]

Convert Rf or RC video signal to components

How do I Convert RF or RC video signal to components
My tv accept components but my satellite box outlet is either RF or Rc..Any help?

 

[jpoopdog]

How do I Convert RF or RC video signal to components
My tv accept components but my satellite box outlet is either RF or Rc..Any help?

you must be new to forums, see, you dont ask questions in other peoples threads, thats rude, also noone will answer you, make your own topic and ask there. as you can see, the title says how do i convert rca signals into component signals. incidentally its a redundant questions as the tft already has a composit video pin i even tested and established to be functional.

On an actually related note, any video i input into the screen doesnt seem to hold a stable video, theres clear black and white, but no colour, or rather, the colour seems corrupted or something, it just forms random fixed shapes slowly scrolling across the screen. any ideas on why this happens?

 

[kubeek]

Maybe because it has incorrect resolution.

 

[jpoopdog]

of course, brilliant!
though, i to my knowledge it only takes nstc or pal . how can i confirm this to be true? do you know how i can test this out?

 

[kubeek]

If it is from a dvd player, I bet there was some other chip responsible for downscaling the source format to the resolution of the lcd. Maybe try looking up the lcd itself and finding what resolution it has. Anyway using something like a DVI to LVDS converter chip and feeding it straight to the lcd connector could be easier than getting a composite outptut with set resolution.