TV Tuner as a User Interface

Hello Paul,

Radio Shack digitally programmable UHF modulator, laptop (or PC) with NTSC output -> bingo!

Paul,

These days it seems acceptable to just have a composite video output -- it's only TVs manufactured better than a decade ago now that don't have composite video inputs, and even those are likely to be hooked up to a VCR that does.

Wireless is pretty much a dead end here, since most people are on cable.

Anyway, then, to generate composite video... if you look in the ads in, e.g., Nuts & Volts or Circuit Cellar Ink, you'll see companies selling boards that do just that. I'm not familiar with all the variations, but I do know that some of them used ICs manufactured for VCR on-screen displays.

If you want to get *really* low-end, you can just use a fast microcontroller and literally "bit bang" the TV display. For a monochrome display, you need little more than a crude 2 bit D->A converter (use resistors) to produce sync, front & back porch levels, and black and white. (If you add a color modulator like an LM1358, you can get two different colors that you can use little trim pots to control!) There are various articles on the 'net and in magazines describing this approach in more detail... the main limitation is that the display resolution you end up with is directly tied to how quickly your microcontroller can shift out pixels; this can be improved by using parallel-load shift registers to do this part, but if you need anything too much fanciful pretty soon it's cheaper to just use an IC made for the purpose.

---Joel Kolstad

Hello Joel,

Except for that "remote viewing" gizmo that X-10 sells. Not sure how they call it but it consist of two little plastic pyramids. One transmits (probably on 2.4GHz), the other receives and outputs composite plus sound.

EnigmaPaul scrobe on the papyrus:

If you're in Europe then your TV will have a SCART connector and you can feed it an RGB signal. The STV5730 is a handy chip for this.

Sony has some small screen LCD TVs that are a bit like that (base station plus portable unit). They're not particularly cheap (12" LF-X1 MSRP 1,500 USD, 7" LF-X5 MSRP 760 USD).

Best regards, Spehro Pefhany

Hello Spehro,

Ouch! Sounds like serious nerdware.

Let's see ... ours was $20 for 13" from a yard sale. The modulator was about $50 plus tax. So we paid around $75 for the privilege to watch the news and the occasional tape under the stars on the deck. With a new TV it would still have been under $150. Heck, you could even leave the TV outside as nobody will want to steal something like that.

I still have to figure out an easy way to make the remote send back commands to the VCR so we can stop/start it in case an important phone call comes in.

I believe the Sony solution will let you pause a playback and then zoom in to Jennifer Love Hewitt's, uh... assets... to the limits of the source material. Can't do that with your $20 yard sale special!

:-)

There are cheap IRRF extenders out there, e.g.,

---Joel

Hello Joel,

What's the ad say? I could, if I wanted to, but I may not want to.

Well, I am married. So even if I wanted to, I couldn't do that ;-)

Thanks. It'll be another thing to plug in on the patio table but this should enable true remote control. I never really understood why remotes have to be IR. Wireless with a self-learning ID shouldn't be rocket science. Even dog training collars have that.