Anybody built a more substantial video interface into their projects

[mclagett]

Hi –

Jus twondering if anyone has gone beyond the two to four line LCD panel for their project and built in something that comes closer to a real computer monitor?  Or somewhere in between four lines of 80 character text and 1280 by 1024 pixels graphic?

Also anybody built in an alphanumeric keyboard interface?

Just curious how one would do this?  The idea I’m exploring is a sequencer that has the visual interface of a ProTools or Sonar, but is built solidly on a RTOS platform.

Anybody done something like thi?

Regards,

Mike

[philetaylor]

I have done a fair bit with graphical displays but nothing bigger than 128x64 b&w (160x104 with 4 grey scales coming soon!)

Personally I think you will struggle with memory as for a VGA (640x480 ) screen with 8bit colour you will require about 300KB of RAM to store a whole screen image (the current STM32 has 64KB of RAM)

One option that I have been looking at is something like this from EA:

http://www.lcd-module.com/produkte/ediptft.html

This is a 4.3" TFT colour display with a resolution of 480x272. The benefit with this is that unlike standard displays, you needn’t manipulate it at pixel level, it includes a controller that allows you to issue simple drawing commands for shapes etc and numerous built-in fonts.

There are 2 main problems though, firstly there is not currently any support for this type of display in MIOS, I have thought about adding it but haven’t mainly due to the second reason, they are VERY expensive

Phil

[Theta_Frost]

I’m fairly certain I heard that graphical LCD’s were supported by MIOS… but you sound like you know what your talking about.  A C64 keyboard has been utilized in a few projects on the user project wiki, check them out.

[Smithy]

Theres also the midibox TV.

http://www.midibox.org/forum/index.php/topic,1533.0.html

Your questions are interesting,

but since the midibox platform is designed to be low cost, i dont know if displaying things at such a high resolution

would be worth doing (or realistically possible in for now).

Making a sequencer like that would take a shitload of work,

and the current projects available on midibox have also taken heaps load of work to get done.

But you never know what the crazy coders on here, are working away on secretly!  ;)

Making something similar to a Roland MC-909,

requires a lot of money, and a lot of hard working people dedicating their careers to this sort of thing. (imo)

And actually, the mc-909 is way below the resolution of what youre talking about,

the only way i trully could see it being done is by building some sort of pc based system,

thats running linux, and say a Midibox Sequencer software application.

[philetaylor]

I’m fairly certain I heard that graphical LCD’s were supported by MIOS…

Yes absolutely they are

This issue is that to display anything other than text and simple symbols will usually need a video buffer which isn’t really practical with larger screen sizes. If you then add colour into the equation as well you will soon run out of memory, that’s why MIOS uses pre-defined ‘fonts’ for any graphics/icons etc as these are static and are stored in flash.

This is something I am doing quite a bit of work on but only with quite small (128x64) GLCD’s. My “MIOS Invaders” program is an example of what can be achieved using these ‘fonts’ and is discussed here: http://www.midibox.org/forum/index.php/topic,13072.0.html

Phil

p.s. I looked at MIDIbox TV and it looks like a fun project but I don’t think it is really practical for creating a GUI (for some of the same reasons as above)