Modular, removable screen concept

[eagle5953]

To save on the time and expense of hacking a pocket TV screen, I thought about making a modular screen that could be transferred between portables. After all, you can't play more than one at a time!

Some searching on these forums showed a few others who had the idea, most notably:
http://www.forums.benheck.com/viewtopic.php?f=2&t=5713

He apparently got hung up at the point of using a USB connection between the screen and the portable. In short, the screen needs 5 pins (video, left audio, right audio, power, and ground), whereas USB, as everyone knows, is 4 pins only.

I considered simply merging the audios together into mono, but that would be somewhat less than ideal. Then I looked a little closer at the mini-usb specification often used in small electronics like mp3 players and digital cameras. It has 5 pins! Subsequent searching revealed that the 4th and 5th pins are both ground.



Therefore, couldn't some hacking allow you to use all 5 pins separately and therefore allow a usb connection between screen and portable?

Post-script: great idea by bioniclebart to power his portable using USB.

[rikitheshadow]

I think the usb works just like AV compenent cables or coax. The outer rim which is always metal, is used for the ground connection. That's why USB ports always have metal shieldings around the prongs and are soldered along with the prongs to the mobo. So yes, i do think you can use USB as 5 prong connector.

[eagle5953]

I think the usb works just like AV compenent cables or coax. The outer rim which is always metal, is used for the ground connection. That's why USB ports always have metal shieldings around the prongs and are soldered along with the prongs to the mobo. So yes, i do think you can use USB as 5 prong connector.

I did a little looking around via google, and although it appears you can use the metal shielding as ground, that wasn't really what I was getting at. The smallest two USB port styles have 5 pins, making that unnecessary.

So it would work then? Does anyone see any issue with doing so?

By the way, where could one obtain mini- or micro-USB female ends? The USB extenders have one of each, but they are full-size USB connectors and are not small enough for use in portables.

[jleemero]

While USB would work for this, there are many other alternatives that could offer even more options.

Cat5 for instance, or perhaps Firewire.
Heck, why not something made for video like DisplayPort, which would be suitable for higher-quality stuff, like RGB or S-Video.


You could find any of this, including USB mini n' such, online.
DigiKey and Molex both have all the stuff you need.
In fact, Molex can give you samples.

[eagle5953]

All good ideas, but I want something that is very small (not Cat5) and very common (not Firewire or DisplayPort). There won't be a cable portion of it at all - I was imaging it to slide in cartridge-style (similar to the VMU of the Dreamcast). Perhaps I will post a graphic of what I had in mind.

Also, thanks for the direction for sources.

edit:

Sorry for the ghetto-tastic windows paint imaging - best I could do quickly!

Note the mini-usb slot on the bottom left corner and the different-sized slots on the left and right sides. Yes, I am aware that the screen cartridge would be a good deal thicker (not drawn to scale).

[bicostp]

Why not just a regular, cheap ol' pin header?

[eagle5953]

Why not just a regular, cheap ol' pin header?

USB is more durable than headers to repeated insertions due to unexposed pins. Beyond that, I think it just looks better!

edit:
One issue that just occurred to me, however, is what would happen if you connected it via usb to something else, such as a computer? It would assume that the 4th and 5th pins were both ground - couldn't that fry something inside if the screen is using the 4th pin for video or audio signals?

[Gordon1]

The removable screen idea is so good, how come I never thought of that? Also, it would be better to only have video going to the screen, because why would the speakers be attached to the screen? That is just dumb. So, then all you would need is ground, 7.5v, and video. And just build a small audio amp that you leave inside the portable.

[Kurt_]

Y'all are too new to remember this (Except Bicostp, shame on you), but it's already been done.

By Gforce. He used velcro and the portable tv's a/v input jack. USB? No need to reinvent the wheel here, people!

http://gtd6288.tollfreepage.com/n64hh.html
http://gtd6288.tollfreepage.com/ps1p.html
http://gtd6288.tollfreepage.com/genesisp.html

[rikitheshadow]

Why not the AV connector cables they used on the SNES, N64, and Gamecube. Can't say it's as small as a USB but it should certainly be easy to work with.

Can't say they sell a lot of the ports designed for the smaller USBs (the ones used on some printers, cameras, and external pocket drives). You would probably have to tear up something to get an item like that.


This might help some?
http://cgi.ebay.com/USB-jack-port-socke ... 240%3A1318

[palmertech]

Screens are not THAT expensive... Why not just give your portable its own screen?

[rikitheshadow]

I like that idea really, its basically like interchangeable parts.

There can be many benefits from using that method but equally as much downsides. I thought of the idea myself once, make a lot of cases that would allow a screen module to slide into place. I'm not saying that its too expensive, but Sony stopped producing the easy hackable PSone screens with the built in Stereo sound, not mono. Which has proven to be the best candidate for any portable project (don't quote me on this...)

Now for some of those who buy the screens from AEIComp, if i'm correct, they do come pre-wired with LED backlight instead of a power consuming cold cathode tube, they still don't come with audio, and the driver boards still require about 12v as compared to the PSone low voltage of 7.5

Portable DVD players are abundant but would require a serious amount of knowledge to mod analog input for the screen.
And I believe the pocket TVs are beginning to fade away considering people can now watch TV on cell phones.

[Gordon1]

Screens are not THAT expensive... Why not just give your portable its own screen?

#1 it is easier #2 it is cheaper #3 it makes sense. Have you actually made anything yet? Or do you just talk a lot?

The modular screen is a great idea, because why would you have more than one portable with you at a time anyway?

For a portable being sold, then yes use a built in screen, personal use... great idea. I might just do this.

[jleemero]

Have you actually made anything yet? Or do you just talk a lot?

I really hate seeing so many damn people say this kind of crap to Palmer.
I especially hate seeing the same person do it more than once.

[XCVG]

Screens are not THAT expensive... Why not just give your portable its own screen?

Actually, screens are quite expensive for many of our budgets. I guess yours is higher than mine.