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1) Route sound around with cat5. Seriously. It transmits signals up to 100mhz, so audio frequencies are a cinch. I don't know though if you need differential drivers at each end or not.

2) Get a decent RF remote control (eg. the Gyration one) or RF keyboard, and make those keystrokes control your music apps via AutoHotkey. This is the DIY route, but AutoHotkey is fast, light, and can do almost everything.

I'm suprised nobody has mentioned lamp life yet. It's a pricy part and has a short life.

2. Video projectors have a very limited bulb life. In other words, if you are watching TV on your video projector about 3-4 hours every night, you would have to replace the light source bulb about once a year at 200-400 dollars a pop.

It's on the right side of the page...he used a Sonic Impact digital amplifier, which uses a Tripath TA2024 chip (you can buy the chip in a DIY kit, as well).

The first thing to realise there are plenty of technology related hobbyists around the world, although most are not high profile and some may be different very different demographics than yourself.

Some (hobby) groups to consider looking towards for ideas and help include: woodworkers, metalworkers (hobbyists using micromills and mini-lathes from TaigTools and Sherline, etc.), model railroads, model aircrafts (static and RC), robotics, amateur radio (ham), 2600, LUGs, and Artist Run Centres/Communities

Random list of some I use or know of:
  Make magazine http://www.makezine.com/
  Instructables http://www.instructables.com/
  ARRL http://www.arrl.org/
  http://www.sparkfun.com/ (check out their tutorials)
  http://www.fpga4fun.com/ / http://www.knjn.com/
  QRP-L http://mailman.qth.net/mailman/listinfo/qrp-l/>
  GQRP http://www.gqrp.com/
  http://www.pololu.com/ (cheap stencils laser cut, e.g. 3x4 for $32)
  http://www.diyaudio.com/
  http://www.digikey.com/ (if you're still buying electronics from Radio Shack, get these 3 catalogs now!)
  http://www.mouser.com/
  http://www.jameco.com/
  the ton of various surplus/NOS dealers online
  http://www.frontpanelexpress.com/
  http://www.seattlerobotics.org/
  http://www.chibots.org/index.php
  DorkBot
  http://eyebeam.org/production/production.php?page= tools
  MIT CBA FAB http://fab.cba.mit.edu/
  http://www.leevalley.com/
  http://www.smallparts.com/
  http://www.danssmallpartsandkits.net/
  http://www.wmberg.com/
  http://www.acklandsgrainger.com/
  http://www.grainger.com/
  http://www.onlinemetals.com/
  http://www.amqrp.com/
  http://www.princessauto.com/
  http://www.sherline.com/
  http://www.taigtools.com/

funnily enough, not all that long ago i stumbled across a bunch trying to do just this on the diyaudio site (sorry but i can't find the thread anymore). Interestingly enough the show-stopper was actually in writing the drivers, not the hardware itself. I almost cried when i reached the end of the thread and found it dead.. :( Anyone here wish to revive it?? :)

oh, the hardware they were trying to design was an audio interface for professional audio.

I built one. My favorite reference, and probably the largest information collection and most active discussion, is at DIYAudio in the "Moving Images" section.

Here's two photos of my results:
http://lserve.homelinux.net:7780/PICT0056.jpg
http://lserve.homelinux.net:7780/PICT0141.jpg

The white bar on the lefthand side indicates one problem you'll have: the internal components of an LCD are very delicate. I can solder 0603 SMD resistors without breaking a sweat, or lift a 208-pin FPGA from a circuit board without damaging either, but I still managed to tear one of the mylar edge connector ribbons loose. Fortunately it was right along the edge and there's still plenty of usable viewing area. I do have another monitor I'll use to replace the broken one, but for now it works.

You do need a fairly dim room, but the image is definitely bright enough. I use a 400W metal halide, but I don't have a reflector so that's one possible way I could upgrade the projector another 30% in brightness. And the cheap lenses have a short focal length, there is no zoom control and to fill an entire 8-foot-high wall, the lens is only 10 feet away. Makes couch placement difficult. I ended up putting my couches in an angled arrangement with the projector in between. Kind of like this: \./ except a shallower angle.

Anyway I like it and it was definitely worth the pain, misfortune, and expense.

I'll provide you with a better forum to search and ask for your goal: http://www.diyaudio.com/ Lots of good stuff there, everything from putting together a decent system for minimal money, to modifying stock equipment with better components.

I can also give you the ultimate crapspeakers. Cheap 5.1 surround that mostly works OK. You know those 5.1 systems at Wal-Mart? Yeah, the ones selling for like $35, which aren't really surround but instead mix out from a stereo signal. I managed to bypass that mixing circuit and directly input the six channels to the volume control IC. It does work on my computer quite well, though it's better if you have Sound Blaster bass redirection, because the satellites are pitifully tinny. I didn't take any pictures when I modded it, but I did buy another one and plan to mod it pretty soon. Really the ultimate in ghetto surround.

If you don't like DIY anything, then this is pointless: but go to DIYAudio and browse through the "Moving Image" section. The DIY LCD projector is becoming very mature and you can select different price and quality options to get price range from almost nothing to $1000. The average projector costs about $300-$400 and requires a few days worth of building. The kicker is bulb price. Typical bulbs used in DIY projectors will last several years, and cost only $40 to replace. As for quality, here's what my first cardboard-and-duct-tape mockup was able to achieve: projected image. And this is FAR behind what the good DIY'ers are getting.

www.diyaudio.com (The Moving Image section)

www.lumenlab.com

www.diyprojectorcompany.com

If you resign yourself to spending $150-$200 in addition to the LCD, you can get some amazing results. To be honest, any cheap overhead projector will have a halogen lamp that has too low of a color temperature, too dim of an output, and will need to be replaced every 25-50 hours. The cost adds up. Also, virtually no overhead projector is big enough to light the entire area of a 15" LCD. You will lose up to 60 pixels on both sides of the screen.

If you instead build your own enclosure, you can do some neat stuff. First, you can show the full 1024x768. Also, you can use a metal halide bulb, which typically have a clean white color and put out less heat for the amount of light produced. And metal halide bulbs last anywhere from 8000 to 20,000 hours. You will also be able to get a high-quality lens for good focus across the whole display, something a cheap overhead might not be able to do.

Go to http://www.diyaudio.com/ and visit the Moving Image forum. There are thousands of posts containing ideas, plans, calculations, optics sources, and photos. I'm in the process of building my own projector with a 400W 6500K metal halide bulb, here's a photo of the image projected by a test mockup: http://lserve.homelinux.net:7780/diyaudio/lightsof f.jpg

I'm rather suprised nobody has said anything here yet.

Basically you just need to put a resistor in series with the LED and battery, to keep the LED from burning out. LED's are a type of diode, which means that one side of the LED must be connected to negative, and one to positive or the current just won't flow.

To find out the resistor value you need, you can use the formula descibed on this Diyaudio page. It also has some info for using multiple LED's in serial. If you have any more questions just leave a reply - I'm no electrical engineer but the Doll house lights thing isn't too big a deal, particularly considering the amount of enjoyment your daughter will get from such a simple hack!

Oh by the way, your local radio shack (if you have those) sells LED's and resistors individually, the forward voltage referred to on the diyaudio page will be listed on the back of the package.

THE OFFICIAL THREAD on Diy Projectors.

I still love mine.

most of the projector projects i've seen start here.. not all DIY projectors are as big as toms
http://www.diyaudio.com/forums/forumdisplay.php?s= 3548cff8095fb76feede9ad32dab91af&forumid=12

also my own DIY projector, build with a 7 inch automotive roofmount LCD, its certainly not XGA, but it gets the job done
http://members.rogers.com/machs_fuel/projector/
probably cost around ~300 CND dollars

http://www.diyaudio.com/ it's an excellent site. I've been building audio gear for a while now and i found that resource invaluable, with contributors as Nelson Pass (from Pass Audio, http://www.passlabs.com/ and http://www.passdiy.com/), Rod Elliot from The Audio Pages, a lot of contributors of Headwize, and quite a few more very knowledgable and technical people.

Highly reccomended, and glad to see someone mentioned it.

Nice links. And here's some karma whoring (not that me needs it).

Creative people and projects:
- http://www.diyaudio.com/ (DIY audio equipment forum)
- http://sound.westhost.com/projects.htm (audio stuff schematics)
- http://headwize.com/projects/index.htm (DIY headphone stuff)
- http://www.hauptwerk.co.uk/pedalboard.html (DIY MIDI pedalboards, just add keyboards and software and you have a MIDI organ)
- http://www.diysubwoofers.org/ (what it says)
- http://www.plasmatweeter.de/eng_plasma.htm (DIY ionic tweeter)

Places to buy stuff:
- http://www.newark.com/ (major electronics retailer)
- http://www.mouser.com/ (major electronics retailer)
- http://www.tubesandmore.com/ (components for vintage electronics)

Getting stuff made:
- http://www.olimex.com/ (cheap PCBs)

www.diyaudio.com is a pretty good approximation of what you are trying to get at I think. I spend a lot of time browsing around those forums, people post schematics, think up new ideas and test them against the community, and help newbies out with building the stuff. Also, they often do "group buys" of the hardware that is necessary so many people can get the stuff relatively cheap.

there's a thread about it here

During the project I was active in the video forum of http://www.diyaudio.com/ , where alot of good thoughts were emerging on the subject of custom projectors - not purely OHP+LCD panel type setups. The five vital factors required to build a decent projector were found to be:

- Good heat dissipation

- A long life, decent color temperature lighting setup

- A well designed reflector

- Decent optics, aligned according to the basic rules of projection (using such items as fresnel lenses, PCX lenses, doublets etc.)

- The highest res. transparent LCD you can afford.

My setup was a custom built upstanding unit, using an OHP Data panel (see-through LCD) and a rather large PCX lense which I am very proud of - it came out of an American tank targeting system and weighs a couple of kilos - it can throw the light from one blue LED about 20 meters!!. I used a 400W Metal Halide bulb with suitable ballast - very bright white light! and fashioned an ellipsoid reflector out of mirrored alu sheeting.

The results? See them at the following link which includes pictures from the very beginning of my tinkering:

http://www.imagestation.com/album/?id=4291451499

The projected image was huge and bright, but the optics system required alot of tweaking. Heat was also a major problem and I melted a few fresnel lenses in the testing stages. Due to university starting up again, I copped out and bought an OHP for some instant gratification. Results of that system can also be seen at the above link.

There's lots of theory behind building a projector, but at the end of the day, you can build one easily if you do your research and can handle very basic geometry. There are many other types of custom build units, including ones using stripped down LCD monitors, fluorescent lighting, very small LCDs etc etc. DIYAudio is a great resource with lots of enthusiastic people posting their thoughts and results.

I found a $300 1024x768 panel on ebay and coupled it with a bright overhead projector I got for $100 on ebay. Sure it's no DLP, but I can watch movies on a 120" diagonal now. It's fun to measure your screen in feet rather than inches. Also, I can now call my 40" widescreen my "small tv."

A google query for "mini-itx lvds" shows this as the first link.

From the thread...

I've found a few Mini-ITX motherboards with LVDS controllers. For those not familiar with Mini-ITX, it's a small form factor type of motherbaord. They are very quiet, and use very little power. CPU, Graphics, Audio, and LAN are all integrated.

The cheapest one with an LVDS controller is $200. It's a 600mhz board, wich is decent enough for playing DVDs and most Mpg-4, and since the board has a PCI slot a TV card could be installed. For $230 you can geta 1ghz board. Anyone know anything about the controller or what type of screen could be used? This could make for a great all-in-one media PC.

diyaudio has a 100+ page discussion of this. Most people are using an overhead projector with their standard lightsources, or mercury vapor or metal halide bulbs. The OHP's fresnel lenses get around the problem of having an LCD panel and lens with different sizes and not wasting a lot of the light(but they're kinda big). Pretty good results have been obtained. However, there are some caveats, the contrast ratio of lcd panels from desktop monitors are pretty poor(under 300:1), decent commercial projectors have contrast ratios > 1000:1. Although I haven't built one yet, I think this can lead to washed out images. Also, nobody has found a supplier for the nice 1-2 inch LCD's used in commercial projectors

A nice thread on DIY projectors, a lot of them are done with LCDs.

diyAudio