IR3Y29B RGB and S-Video!

[segasonicfan]

This has been a long time coming....for those that don't know, the IR3Y29B is a *very* common video encoder circuit among LCD devices like portable DVD players, portable TV tuners, and even the Hip Gear has it.

The problem with all these devices that have the encoder is they only use composite video for EVERYTHING. Even my TV Tuner uses composite to show TV channels. Being obsessed as I am with hi video quality I've been working for a long time to input RGB and/or S-Video into this circuit. Fortunately, I've figured out how to do both thanks to some testing and careful reading of the datasheet. This info applies to the Hip Gear and anything else that uses the chip:

To get S-Video:

isolate pin 5 is the main trick here. It's often soldered to ground so it takes some careful desoldering + lifting to isolate it. When grounded pin 3 is the composite input and this is the default mode used. Once isolated (in hi state) the chip enters S-video mode. Input chroma to pin 5 through a .1uf cap and input luma through pin 3 (composite input).

Troubleshooting: the only problem I am having with S-video is some strange chrominance capturing by pin 3. When just luma is inputed there are some small edges of color that don't belong. I've tried a chroma filter but I haven't figured how to remove this yet. However, it is relatively unnoticeable and still an increase in quality from composite IMO.


To get RGB:

isolate pin 39. It is usually grounded which makes the circuit function in composite/S-video mode. When lifted (hi state) the circuit enters RGB mode. Pins 40 (B), 41 (G), and 43 (R) are the RGB inputs. Just series a .01uf (103 rated) cap for each signal input. For sync, just solder the C sync signal to pin 36. This pin functions as a sync splitter so inputting composite video should give you sync as well.

Voila, the RGB looks terrific and there isn't anymore annoying dot crawl/cross-color artifacts :) Now portables can be in their full-video quality glory ^_^


Note: I will be working on the pinouts/info for image adjustments with this circuit later. Many inputs could use contrast/brightness/color/etc adjustments that the chip has but aren't always available on the PCB itself.

-Segasonicfan

[Turbo Tax 1.0]

awesome! now i might be able to get RGB on my SNESp

thanks man

[csurban]

Just for clarification, you are talking about inputting better quality video signals into a chip on a screen mobo. Correct me if I'm wrong but doesn’t the PSOne screen accept RGB natively?

[gannon]

Yes, but this is for other LCDs

[Krepticor]

can we get a list of screens that use this chip?

[segasonicfan]

Here's a schematic I made for those interested in the mod:



It's impossible to list all the things out there that use this chip. The Hip Gear uses it, my Casio portable TV uses it, and many of my portable DVD players use it.

[Anderson21]

I have a Hip Gear and was wondering if it would be possible to use this to replace the screen in a turbo express.

Is the RGB accessable from the holes the wires are normally soldered to ?

I have wired up a pc engine via composite to the Hip Gear and the picture was very good but i guess it would be better being RGB.

Does any one know what the pin outs of the connector on the turbo express to the screen module are?

[timmeh87]

does the psone screen use it?

[MrTroy]

timmeh87 ... It doesn't matter.

I wish you had pictures posted so I could see what's going on in there. I guess I gotta go home and hack up that Hip Gear screen I've been procrastinating on.

[Krepticor]

is there a way o find what screen use this chip?
or do we just buy every large sharpe screen and hope for the best?

[segasonicfan]

is there a way o find what screen use this chip?
or do we just buy every large sharpe screen and hope for the best?

The number and "sharp" are written on the chip. Pretty easy to find. The PSOne screen does not use it.

-Segasonicfan