So I was browsing Anandtech Hot Deals and I come across this deal. They're Playstation2 and Xbox controllers with built in 2.6"TFT screens for only 20 dollars. I figure the screen alone is worth more than that. I don't have an Xbox so a hack is the first thing that came to mind. The screen should be good for something, and Xbox controllers are really USB controllers, so they're good for something as well. Two for one hack! Don't get much better than that. I'll deal with the screen for now.
That's the ginormous humongo controller that is the ScreenPad. Soon the screen will be removed from the controller. But what shall I do with this screen? It accepts plain ol' composite video input, and regular RCA stereo audio. So what the heck, DVD player for my car it is. So the ScreenPad was 20 bucks. Let's set a budget! Let's say get this done for under 50 dollars. So I tried looking for a used DVD player. I would have taken anything! I figured most DVD players run on a simple powersupply, and that I could make it run on a cigarette lighter in a car simply using voltage regulators. And then I could shrink the whole player by eliminating the 110AC power supply, and making a cool pimptastic clear acrylic case a la Emubox. But a quick search on Craigslist yielded nothing good. So I hopped on Best Buy's website and saw a cute little DVD player for only $36.99. Ok so I'm a little over budget, but it's so small! This would save a lot of trouble since I didn't have to make a custom case for it; it's small already! Plus I could keep the AC powersupply to keep the DVD player usable at home.
Awww.. it's so cute! As adorable as it may be, it is not immune to my screwdriver! Well.. not yet. I gotta plug everything in to make sure it works.
Here the combo is playing the best movie of all time: The Rock. The screen looks like crap in that picture, but it's actually pretty good. You can tell the resolution isn't really that high, and you can really see pixelation in text on the screen, but it's better than even I expected it to be. What's also cool about the screen is that there are screen adjustment knobs right on the front of the screen. So adjusting the picture according to the changing light conditions in a car should be a snap. There's Color, Brightness, Contrast, and Volume knobs right under the screen. Sound is crap though. But there's a headphone jack, and my Sennheiser MX-500 earbuds sounded decent through it. Anyway.. testing done, now to the get to work.
So I open up the DVD player and see the power supply board. It takes AC power and through some magic and hocus-pocus, spits out 12Volts and 5volts for the player to munch on. The plan was to use one of those Universal Power car multi-headed adapter things. Voltage is adjustable with a slider switch. I opened mine up just to see what was in it, and I see it's a LM317 adjustable voltage regulator. The regulator can take up to 40Volts input and has variable voltage output, adjustable with resistors in a simple circuit. So the slider switch in the Car adapter simply changes a resistor network to change the output voltage.
Anyway, with the power adapter, the DVD player will have a healthy source of regulated 12volts. Now for the fiver. It just so happens the LM7805 voltage regulator is a 5V regulator. And I happen to have a few of these in my parts drawers. Since I'm stepping down from 12V, 5v and drawing an unknown amount of current, I thought it a good idea to glue a heatsink to the regulator too.
Well long story short, the DVD player wouldn't start up after my ghetto modding. So after doing some cursing and probing, I discovered my 7805 was putting out only a feeble 3 volts. Well my DVD player was hungrier than that! So after digging around my junk, I found an old CD-ROM drive that I've canabalized for other parts. And on the board was a nice 7805 that was in a bigger package. It's the bigger package size that has the hole through it for bolting on a heatsink. So I swapped out the 5v regulator and BAM! The player started right up. To cool it I drilled a hole in the bottom of the DVD player case, and bolted the regulator to the case with a small machine screw and nut. I remembered to put some thermal grease under there too to aid heat transfer.
So now I wanted to make the AC power usable too. So i made a little switch that switchs between AC and DV power modes.
Here it is, done. You can see a little bit of the voltage regulator that's bolted to the case. I drilled a couple of holes in the back panel for the power input and the power output for the Screen to use.
The screen didn't require much modification. Just pretty much removed it from the controller, and neatened up the wiring. I got rid of the Xbox related plugs and left just the Audio/Video plugs, and the power port.
Here it is done! Playing is the second greatest movie of all time: SpaceBalls!
Here's the back panel. You can see a little hole for the power input from the Car Adapter. And you can see the pigtail power plug for the screen. And near where the AC cord comes out, you can see the little tiny switch I'm using to switch between AC and DC power.
Here you can see the screen. Note the CustomGhetto(tm) jagged bottom edge where it was painfully removed from its host. You hold it like a Gameboy Advance. I may make some sort of bracket to clip the screen to my airvent or something. But something that fancy and useful might be a bit much for this ghettohacker.
Oh and the screen has a cool A/V plug too. It allows you to piggyback more than one screen. This was so you could use a bunch of the Screenpads to play multiplayer games on your console. But this might be cool so that everyone in the car can have his own teenytiny squint-o-screen for himself. cool nonetheless.
So how am I gonna actually use this thing in my car? Well the ghetto way would be to just throw it in the floor of the passenger seat, plug it in, and let whoever wants to watch A Christmas Story just hold the damn screen. Yeah that's pretty ghetto, and good enough for me.
Update: March 22, 2004
I just got back from a weekend trip to Tahoe with the DVD player in the car. First of all, it's very distracting to the driver (me). Driving in the middle of the night, and having a Jet Li kungfu movie playing at the same time is not a good idea. Second, it made my girlfriend carsick. She doesn't do too well just driving on curvy roads, so I guess having a movie playing in front of her wasn't the smartest thing for me to have in the car. And third, even though the DVD player is pretty small, it's still a burden to have it taking up space in passenger seat footwell. And the wires are a pain to have dangling all over the place. Looks like I'll have to do some more cutting. I'd like to have a removable AC power cord, and really really short A/V interconnect cables. And it'd be nice if I could set the player vertical. The disc tray doesn't have those little clips like on PC optical disc drives that hold a disc on the tray even with the drive vertical. Maybe a tray swap is possible. Or maybe a ghetto mod of disc holding clips.. Stay tuned.
Update: April 04, 2004
I redid the power jack to something that's not just glued on. Got a panel mount jack at Radio Shack. It's a N size which apparently means 5.5mm OD and 2.5mm ID. The car adapter thing has a plug that fits into it, but the pigtail that powers the screen is 2mm ID, so it doesn't fit into the jack. But that doesn't matter anyway. So I installed the new power jack as well as a Double Pole, Double Throw (DPDT) switch to select the power source, 110VAC or 12VDC. This was ripped from an old PC power supply (By the way, old power supplies are a good source of general purpose hookup wire) And I also shortened the A/V cables that came with the DVD player to about 4.5inches just so they don't take up so much room in the car. And I put a rubber grommet in the hole where the pigtail comes out of the case so it won't wear through the insulation. I still don't have a removeable AC power cord but I've found that if i just wrap the cord around the DVD player, it doesn't take up too much room.
Here are some new pics:
There's a decent shot of the screen. It's playing a CD full of MP3's in subdirectories. It handles mp3's pretty well, but blows at playing MPG files. I can't find a way to get to the file browser except letting it play through the last file in its entirety. So that kinda sucks. But I don't do that too often, so oh well. I'll live.
I just noticed that all the holes I punched in the case are located right where it has that big CAUTION ELECTRIC SHOCK warning label. I guess I was lucky that I didn't suffer irreparable damage to my self. Pretty amusing.
Added a removable AC power plug to the DVD player. My dad the electrician found the socket somewhere, not sure where, but it works perfectly here. Now I don't have to have the stupid AC power cord tied up with the unit when it's sitting in the car. And I just realized I should put the date when I first posted each page, not just the updated date. I'm dumb.