TV Display Chip

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- 1st March 2008, 11:17
zadok

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TV Display Chip

I've been working for some time (far too long!) on a single chip solution to display energy monitoring results to a TV (see photos).

It crossed my mind that as this display can cope with up to 1,000 alpha-numeric characters, including multiple bar graphs etc, far more than an alpha-numeric LCD panel, the chip might be useful to other people who are finding an LCD panel a bit cramped. Despite searching for weeks before I started the project, I couldn't find a suitable off-the-shelf display chip, so decided (unwisely in terms of the work involved) to do my own.

I was thinking of maybe offering the chip with a single wire serial input so it could also be used with radio links, infra red etc. As it would only use one I/O, even connection to a lowly 8 pin micro would give a useful display, and may be useful for debugging and testing at least. Its already got built in binary to decimal with floating point, bar graph display function and hex dump for debugging.

Maybe other people know if such a type of chip already exists. The only ones I could find were not really suitable; black & white only with characters which were too wide and too much of a gap in between the characters.

I'm just floating the idea to see if anyone thinks it would be useful to them.

If so, any comments?

Graham.

PS The photos are direct camera shots of a TV screen and for some reason turn out a bit blurred. The actual clarity is better than this.
- 1st March 2008, 17:19
dhouston

I think it will depend on price and capability. Most of the commercial video overlay chips have been discontinued but BOB-II and OSD-232 offer black & white overlays with reasonably sized letters. BasicAtom has a video overlay but it's fairly crude. I haven't seen a color chip. Will this be NTSC, PAL or both? Canl it overlay the picture or does it need a channel of its own? What's the expected cost?
- 1st March 2008, 20:02
Normnet

See MAX7456 On-Screen-Display.Forums

Maxim's web seminar "Bridging the Gap in OSD Generators"

Norm
- 1st March 2008, 22:05
Archangel

Parallax propeller chip features VGA output . . .
- 1st March 2008, 23:27
b1arrk5

Graham,
It looks good, but here in the States analog TV is going to go away early next year, although a lot of analog sets will still be working using converters for some years to come I imagine.

I'm curious to know how you are reading the kilowatt hours, it looks like a neat project.

Thanks,

Jerry.
- 2nd March 2008, 08:47
nomad

how much?

I'd be interested in them to play with, as hobby. i assume they are line level video output? so whether a tv is digital or not wont matter?
- 2nd March 2008, 19:04
zadok

Quote:

Originally Posted by dhouston

I think it will depend on price and capability. Most of the commercial video overlay chips have been discontinued but BOB-II and OSD-232 offer black & white overlays with reasonably sized letters. BasicAtom has a video overlay but it's fairly crude. I haven't seen a color chip. Will this be NTSC, PAL or both? Can it overlay the picture or does it need a channel of its own? What's the expected cost?

I'll try to answer these questions.

1. It will be PAL first then NTSC next.
2. Currently needs it's own channel but I could easily offer an overlay option.
3. Expected cost. I notice the monochrome MAX video chip mentioned by someone else was around $9 in 1,000 off. I was considering under $10 for 1 off, not sure on quantity.
- 2nd March 2008, 19:06
zadok

Quote:

Originally Posted by Joe S.

Parallax propeller chip features VGA output . . .

That's a really interesting chip. A bit more than most people need I think - I wonder how difficult it is to use for it's display capabilities. Not a bad price at all for what you get though...
- 2nd March 2008, 19:09
zadok

Quote:

Originally Posted by nomad

I'd be interested in them to play with, as hobby. i assume they are line level video output? so whether a tv is digital or not wont matter?

Yes it's direct video, RGB plus SYNC in fact. Present version plugs into the SCART socket but could be connected to any RGB + sync input.
- 2nd March 2008, 19:21
zadok

Quote:

Originally Posted by b1arrk5

Graham,
It looks good, but here in the States analog TV is going to go away early next year, although a lot of analog sets will still be working using converters for some years to come I imagine.

I'm curious to know how you are reading the kilowatt hours, it looks like a neat project.

Thanks,

Jerry.

As I understand it, just as is happening most places, old analog transmissions over the air are being phased out, but TVs will still accept PAL/NTSC signals otherwise nobody could view a DVD for a start.

Do US TV sets generally have RGB inputs or just a composite video? Most European TVs will display NTSC signals as well as PAL, I think that NTSC sets will probably display PAL if the signal is fed in at an RGB/sync level. I need to check on this!

Reading the KW/h - it's projected from reading a PV solar cell and multiplied up depending on the size and type of solar panel being considered. Wind power is worked out by counting pulses from an anemometer.
- 2nd March 2008, 20:07
Archangel

Quote:

Originally Posted by zadok

As I understand it, just as is happening most places, old analog transmissions over the air are being phased out, but TVs will still accept PAL/NTSC signals otherwise nobody could view a DVD for a start.

Do US TV sets generally have RGB inputs or just a composite video? Most European TVs will display NTSC signals as well as PAL, I think that NTSC sets will probably display PAL if the signal is fed in at an RGB/sync level. I need to check on this!

Reading the KW/h - it's projected from reading a PV solar cell and multiplied up depending on the size and type of solar panel being considered. Wind power is worked out by counting pulses from an anemometer.

Most older U S Televisions do not even have composite video
only antenna connections, most VCRs do have composite video, a few may have RGB. The media lobbies are very powerful here and have caused U S sellers of equipment to lag behind the rest of the world in giving U S consumers the power to manipulate video, they fear profit loss if we have that power. Look Digital sound recorders were kept out of American hands for years, only recently have we had that technology in hand. As a result we bought the same music over and over, vynal,4 track, 8 track, cassette, CD . . .Money talks BS Walks!
- 2nd March 2008, 20:08
dhouston

Quote:

Originally Posted by zadok

I'll try to answer these questions.

1. It will be PAL first then NTSC next.
2. Currently needs it's own channel but I could easily offer an overlay option.
3. Expected cost. I notice the monochrome MAX video chip mentioned by someone else was around $9 in 1,000 off. I was considering under $10 for 1 off, not sure on quantity.

If you can offer NTSC and overlay for about $10, I'd certainly be interested and I think you would find a ready market. Please keep us informed of your progress.
- 2nd March 2008, 23:29
nomad

most all current tv's here have composite input, some have rgb and s-video also. most will not display a pal signal. when you have some for ntsc put me down for a few.
- 3rd March 2008, 17:28
zadok

Quote:

Originally Posted by dhouston

If you can offer NTSC and overlay for about $10, I'd certainly be interested and I think you would find a ready market. Please keep us informed of your progress.

Overlay seems to be something which is mainly used for security camera systems etc. TV signal overlay chips cost far more from what I can gather, although (I think) I've worked out how to do it with just the basic chip. What proportion of the demand would you expect to require overlay - say half?
- 3rd March 2008, 17:38
skimask

Quote:

Originally Posted by Normnet

See MAX7456 On-Screen-Display.Forums
Maxim's web seminar "Bridging the Gap in OSD Generators"

Norm

I had a play with those last year...even had some 'breakout' boards built for the TSSOP package. The image never quite turned out right. Probably due to my sloppy 'breakout' board, or maybe the connections, etc.etc.
The characters don't follow the standard ASCII character set, easy enough to fix with a lookup table. And the characters are reprogrammable, but I didn't play with that.
If there's enough interest, maybe I'll get another bunch built up.
- 4th March 2008, 00:29
b1arrk5

Graham,
I don't own a digital TV yet, but you're probably right, they should play rgb just fine, I was thinking NTSC composite overlay would be a problem. My wife and I decided that since we have low resolution eyes, (over fifty, bifocals, etc.) we don't yet need a high resolution TV, and the prices will likely fall.
Thanks for the info regarding the PV cells. Our local electric utility is going to become unregulated next year and electric prices are expected to jump significantly.

Jerry.
- 4th March 2008, 03:20
dhouston

Quote:

Originally Posted by zadok

Overlay seems to be something which is mainly used for security camera systems etc. TV signal overlay chips cost far more from what I can gather, although (I think) I've worked out how to do it with just the basic chip. What proportion of the demand would you expect to require overlay - say half?

This might just be my personal preference but I think more than half. Things like Caller ID, doorbell, car entering driveway and other messages should overlay whatever channel is currently selected so there's no additional action required by the user, while things like your power monitor can use their own channel.
- 14th April 2008, 01:09
RYTECH

I'd fork out the 10 -25 dollars for a kit / chip that alloud output to a tv monitor via simple coax / composite connection (ntsc? North America). Please let me know if you intend to offer such a thing..
- 15th April 2008, 23:32
b1arrk5

See the April issue of Circuit Cellar Ink magazine, one chip, one capacitor, three resistors, and written in PicBasic Pro and Assembly.

Jerry.
- 17th April 2008, 22:17
RYTECH

Thanks I'll check that out...