Picaxe Compatible video!

[andrewpro]

So I was poking around sparkfun electronics website and found these new NTSC/PAL modules (well..new to them).

This first one: <A href='http://www.sparkfun.com/commerce/product_info.php?products_id=749' Target=_Blank>External Web Link</a>

Is $33.95 US, will display 6 lines of 16 characters each, and has a very basic sound output. Controlled by a 4800 baud serial connection, it could be accessed by the X and M parts.

The second one: <A href='http://www.sparkfun.com/commerce/product_info.php?products_id=750' Target=_Blank>External Web Link</a>

Is a bit more expensive at $54.95 US, and doens't have sound, but can display 8 lines of 24 characters, and can be accessed over a 2400 baud connection, making it suitable for the entire picaxe range.

Just thought I'd pass it along in case anyone would be interested <img src="smile.gif" width=15 height=15 align=middle>

--Andy P

Edited by - andypro on 21/06/2006 07:02:31

 

[kranenborg]

Hello,

You may have a look as well at:

www.speechchips.com

They sell two video IC's, somewhat simpler (only text, no video overlay) but also cheaper

Best regards,
Jurjen
http://www.kranenborg.org/jurjen

 

[hippy]

There's always the option to 'roll one's own' video interface using a PICmicro, AVR or other microcontroller, but that does take some effort to get right. Most video controllers are precisely that, and their cost represents the significant effort to do that and in getting a professional and working result.

My preference would probably be the $25 USD Propeller Chip from Parallax, which can be programmed to generate one or more (!) full colour or monochrome hi-res NTSC/PAL video / VGA ( graphics and/or text ), and could also be used to handle other 'high speed slave' functions a PICAXE might need. It's also DIP packaged which is very handy.

Example : http://forums.parallax.com/forums/attach.aspx?a=7641
Close-Up : http://forums.parallax.com/forums/attach.aspx?a=7642

A 'ready to go' serial-to-TV Propeller Application for PICAXE users would be an excellent project for someone so inclined.

 

[andrewpro]

Those speechchip offerings are pretty cool. Especially the 8 pin one! Nice and small.

I've attempted to go down the video path before with an AVR. It's a whole lotta work, and i never quite got it to work just right. Assembler is definitely NOT my forte!

The propeller stuff definitely looks nice. Way higher res than most other offerings. I wonder, though, if it can successfully fill the entire screen like that, or was that the extent of it's capabilities. If it could fill the entire screen, it would definitely be worth loooking into.

--Andy P

 

[hippy]

It looks possible to fill the whole screen; 80x25 = 4KB, 160x50 = 16KB, and there's 32KB to use. Memory requirements are quite samll compared to a byte/nibble-per-pixel bit-mapped graphic.

My own efforts on bit-banging video were &quot;impressive&quot;, but equally &quot;disappointing&quot; in quality, and it takes an awful lot of work ( and needs the right tools ), which makes commercial kit quite cost effective.

I like the Propeller option because it is much higher resolution, software already exists ( TV, video and full-duplex background serial ), which means it's more a case of making it work and tweaking than designing from scratch, and fairly cost competitive.

 

[erdc]

Here someone made a game of Pong and Tetris using a Pic <A href='http://www.rickard.gunee.com/projects/video/pic/gamesys.php' Target=_Blank>External Web Link</a>

 

[hippy]

That was the place from where I started my own video project, and there's a very good link there explaining the principles ...

http://www.rickard.gunee.com/projects/video/pic/howto.php