PSP LCD Screen Modification To Output To Alternate Source - Tech Peeps Needed Inside

[replicashooter]

Greetings all

I found this forum in a search for information on my proposed modifcation of a Sony PSP console into a home based console.

What I plan on doing is interfacing a standard PS2 controller to the PSPs control points inside thus controlling the unit externally.

For the picture I'd love to be able dump the LCD signal into whatever can process the signal for output to a standard TV, if thats not possible then I wouldn't mind being able to outputting the signal to a larger LCD panel.

Here's the info I've obtained so far:

The PSP2TV solution offers a similar deal to what I'm looking for but due to the poor upscaling method which chops the native resolution in half then replaces the missing lines with repeated data you get a very poor TV output (blockiness/artifacts).

LCD information

Manufacturer Sharp
Part No LQ043T3DX02
Interface 24-bit digital (8 bits/color)
Pixel Format 480x272
Size 4.3 inch (10.9 cm) 16:9 aspect ratio

More information at the Sharp site and the PDF spec sheet along with the connector datasheet. Here is the pinout for easy reference:



Unofficial info

From other various sources and people I have managed to glean the following tidbits:

The PSP screen differs to a standard LCD interface as the panel has an intergrated controller - Does this mean that if you stick a DAC on each of the three colour signal outputs you'd have analog video as the H and V sync are already there?

So how feasible does this mod seem to you lot? Any ideas or pointers in how to take a signal from the PSP mobo and convert it or route it to an alternate LCD?

Thanks

[mothflavour2]

I am aware that it's bad etiquette to exhume old topics, but I'm likely not the only one who's interested in finding this information online.

Anyway, there's no saying that it's not possible. Considering the 8-bit parallel interface for each colour, you can theoretically run the outputs through a DAC for VGA output. Either that or use some kind of an 8-bit-to-serial buffer and a microcontroller for DVI-D output.

What I'm interested in is interfacing to the LCD. In other words, using the LCD screen for a custom project. The LCD that I'm considering using is the Sharp LQ043 K3146. It appears that this LCD uses the same pinout as the one for the datasheet posted above, as this screen is marketed as a Sony PSP replacement.

I've done a bit of research into using a Microchip PIC to control the screen, and possibly 3 8-bit A-D convertors to convert VGA (or the VGA signals from DVI-I) into signals that the screen can use. VGA operates with a Master Clock of 25.2 or 28.3 MHz, so unless you use one of the 40 pin PIC18F series that can operate at 40MHz, I don't see it happening. Actually, many of the PICs have built-in A-D convertors, which could make it easier to create a bit of an all-in-one interface.

[error401]

I've done a bit of research into using a Microchip PIC to control the screen, and possibly 3 8-bit A-D convertors to convert VGA (or the VGA signals from DVI-I) into signals that the screen can use. VGA operates with a Master Clock of 25.2 or 28.3 MHz, so unless you use one of the 40 pin PIC18F series that can operate at 40MHz, I don't see it happening. Actually, many of the PICs have built-in A-D convertors, which could make it easier to create a bit of an all-in-one interface.

A small microcontroller isn't likely to be fast enough to handle this. You'd definitely need external A/D, as the A/D in most small micros takes on the order of a few hundred to a few thousand cycles depending on precision. Even at 40MHz you're nowhere close to a sample per pixel.

Consider: 480x272 = ~130K pixels. We'll make it easy and say 30fps, so 130K x 60 = ~8Mpixels/second. That means you need A/D that can do at least 8Msps. Not hard to achieve, most IC houses will have one. Check out ADS830 from TI for example. I'm not sure how a PIC would be useful for anything other than housekeeping. Just connect your ADCs directly to the LCD data bus, it's parallel so it should be easy.

Easiest solution would be to run the ADC from a high sample rate clock (higher than the VGA hsync rate), with the data buses connected directly to the LCD and feed hsync and vsync directly to the LCD as well (probably requires level conversion though). Read the ADC datasheet and make sure the data latency is accounted for (e.g. your sample rate is high enough that the data you output matches the time window for the hsync/vsync pulse when it appears).

This part probably isn't too hard. What the other poster wants to do is probably a bit trickier since you actually need to generate a valid NTSC signal, which is non trivial. If you tapped those LCD lines and created an intermediate VGA signal which you then converted to NTSC with an off the shelf solution it wouldn't be too bad. Basically do the reverse and connect 3 fast 8-bit DACs to the LCD control lines and you've basically got VGA.