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Topic: TellyMate Shield - TV output for Arduino (Read 57148 times) previous topic - next topic


Take a look on what these guys are doing...


Schematics, source code, precompiled hex files and examples available.


love the idea, finally cheap and huge displays (old CRTs :)



Great idea.

For a next batch, maybe some kind of drawing capability outside of chars alone?


Very cool product and their web site said they are now shipping wordwide so I had to go ahead and send for one.

Thanks for the tip.



Lot's of modern LCD TV's also have a compositive video input. I've ordered one to have a play with it.



Your website says the characters are 38x25 characters.

What are you considering the video's full screen resolution?


Your website says the characters are 38x25 characters.
What are you considering the video's full screen resolution?

Display resolution is irrelevant.   The limiting factor is that the AVR CPU used can only output so many dots per scan line...


May 17, 2009, 02:55 am Last Edit: May 17, 2009, 02:55 am by george_graves Reason: 1
That's what I'm asking - what is the display resolution of the overlayed graphic.


The TellyMate (and it's schematically identical sister, the TellyMate Shield) can only output characters.
Each character is 8 pixels wide by 9 pixels tall.

There is a slight complication in that the last of the 8 pixels is twice as wide as the others

Technically, you could claim that means a resolution of 304 x 225 pixels, but that's really misleading, as they're not directly addressable, and are only driven via the ROM-based font (so aren't even user definable).

I have written an article about the design of the TellyMate which details how it all works.

The following diagram shows a small example of what's output:


Your article is very good; lots of technical meat to it!


i take it there is no sketch i can upload to the 168 so i can breadboard a simple tryout..

i plan on buying a telemate kit or shield at some point tho :3

but til then i want to output something to a tv :P


If you want to breadboard a TellyMate, there's circuit schematics (sch_tm_13.pdf) and source code (code_tm_19.zip) available from the Batsocks site.
If you just want to build one to talk to an Arduino, its actually rather simple, as TTL level serial signals are used (e.g. there is no need for the optional input conversion circuitry). You'll be able to do it with just a few components.

I've not previously had the firmware compiled for a Mega168 (M8 and M88 only), but I've just had a go, and it seems to be possible with a very simple source-code change: Anywhere that references _AVR_IOM88_H_ should be changed to use _AVR_IOMX8_H_ instead.

I'm afraid that I've not been able to verify that the (modified as above) firmware actually works on a M168 (I only own lowly M8 and M88s), but I can't see why it wouldn't.

I'm actually itching to try putting the TellyMate onto a 328 so that I can play with it's 2kb SRAM, but unfortunately all supplies of the 328 seem to have dried-up, and I don't think Atmel are interested in talking to the little-people about samples.

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