Text or image?

dosmith · 2011-01-11 11:48

I've been playing around with the VGA text demo file originally created by Chip Gracey in 2006 to create a device that we can use with our emergency notification system. The thought occurred to me that using a small graphic file might be easier than trying to do this in text. Anyone agree with that concept? If not, then I'm looking for someone to walk me through the code to edit parameters of the text including colors, size and background colors. Anyone interested? Thanks.

Oldbitcollector (Jeff) · 2011-01-11 13:00

Can you tell us a little more about what this project will do? It'll help.

I take it that you need VGA output?

OBC

dosmith · 2011-01-11 13:46

We're trying to leverage our classroom control system to augmented a campus-wide emergency announcement system. Basically what we're looking to do is create a small device that will plug into an open vga input on a classroom projector/monitor that is constantly displaying a message (or an image depending on the input from all of you) instructing the viewer to follow some instructions. We've built a prototype device and it's currently displaying text but I don't have the skills to edit the text well.

Oldbitcollector (Jeff) · 2011-01-12 07:18

Take a look at the "VGA_Text_Demo" in Propeller Library - Demos (In Propeller Tool)

Is this what you are looking for? Or something more jazzy?

OBC

potatohead · 2011-01-12 07:27

Are these instructions like, "Please go to Area 1C right now.", or "Fire Drill in Progress...?", or something longer?

Oldbitcollector (Jeff) · 2011-01-12 07:47

If it's just text you need, we can narrow that demo down a little.

''***************************************
''*  TV Text Demo v1.0                  *
''*  Author: Chip Gracey                *
''*  Copyright (c) 2006 Parallax, Inc.  *               
''*  See end of file for terms of use.  *               
''***************************************

CON

  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000


OBJ

  text : "tv_text"
  

PUB start 

  'start term
  text.start(12)
  text.str(string(13,"The building is on fire!",13))
  text.str(string(13," PANIC! RUN! SCREAMING!",13))

I'll await your good humor and response to potatohead's question.

OBC

dosmith · 2011-01-13 06:25

Yes, I've been working with the VGA_Text_Demo file with some success and yes it's a static message with basic emergency instructions. What I haven't been able to figure out is how to control font and background color and basic editing controls. This is also why I asked the question of whether to use text or a graphic thinking that I can edit a graphic very easily. Thanks for the help.

Oldbitcollector (Jeff) · 2011-01-13 06:41

> basic editing controls.
Are you looking for a way to change/edit text with a keyboard?

I'm not sure font change is going to be available. I believe background color is doable with that object.

OBC

dosmith · 2011-01-13 07:36

Nope. I can send you what I've got. I was able to figure out how to get the text I needed but not how to control line breaks, any color options, etc. Basically we'll program these once and put into production. I'm still interested to know whether or not using a simple graphic image would be more effective. Thanks.

potatohead · 2011-01-13 08:37

A graphic would be simpler from the authoring point of view, but more difficult on the Propeller because the graphics take considerable program space.

So we need some detail:

1. How many messages are there?

2. If only one or two, you can use a graphic. We have drivers that can change colors and such, and display simple bitmaps. 2 or 4 or 64 color bitmaps. Probably store only one 64 color one, a coupla 4 color ones, and maybe three 2 color ones. (and that's a rough guess based on a rough idea of content)

3. if more, then do you have storage on your board? SD card, or large EEPROM?

Based on that, we can give you some advice.

The storage method will require that a VGA driver is up, whatever communications you plan to use, and either SD or EEPROM driver code to be able to fetch the graphics.

If there are a lot of messages, then it's better to draw text, and there are some things that can be done. It won't be like your average graphics program can do with fonts and such, but you can make some adjustments. Each takes some work.

Since you said it's a emergency system, I suspect several, or perhaps some ad-hoc message to be displayed at emergency time...

Ariba · 2011-01-13 14:14

Text is much simpler than graphics, especialy respecting colors.
With TV_Text you can choose one of 8 color-sets for every character. Such a color set defines fore- and background color.
Further you can change the palette which defines the 8 color sets, on the fly.
Here is a demo:

CON
  _clkmode        = xtal1  + pll16x
  _xinfreq        = 5_000_000

OBJ
  tv : "TV_Text"
  
PUB Main   | i
  tv.start(12)
  tv.setcolors(@palette1)       'set our palette
  colorset(0)                   'color nr of palette
  tv.str(string("Text Color Test",13))
  repeat i from 0 to 7
    at(4,i+2)
    colorset(i)    
    tv.str(string("ColorSet "))
    tv.out("0"+i)
  
  waitcnt(clkfreq*4 + cnt)
  repeat                        'change colors
    tv.setcolors(@palette2)
    waitcnt(clkfreq + cnt)
    tv.setcolors(@palette1)
    waitcnt(clkfreq + cnt)
  
PRI colorset(cnr)
  tv.out(12)
  tv.out(cnr)

PRI at(xpos, ypos)
  tv.out(10)
  tv.out(xpos)
  tv.out(11)
  tv.out(ypos)

DAT
             '      fore   back   set            also border 
             '       color  color                 |
palette1     byte    $07,   $0A    '0    white / dark blue
             byte    $07,   $BC    '1    white / red
             byte    $9E,   $9B    '2   yellow / brown
             byte    $04,   $07    '3     grey / white
             byte    $3D,   $3B    '4     cyan / dark cyan
             byte    $6B,   $6E    '5    green / gray-green
             byte    $BB,   $CE    '6      red / pink
             byte    $3C,   $0A    '7     cyan / blue

palette2     byte    $07,   $DC    '0    white / violet
             byte    $3C,   $0A    '1     cyan / blue
             byte    $07,   $0A    '2    white / dark blue
             byte    $04,   $07    '3     grey / white
             byte    $3D,   $3B    '4     cyan / dark cyan
             byte    $9E,   $9B    '5   yellow / brown
             byte    $6B,   $6E    '6    green / gray-green
             byte    $BB,   $CE    '7      red / pink

Andy

dosmith · 2011-01-14 14:39

We're working with a single, static message. As for size of EEPROM we used the same one that comes with the propeller starter kit. Basically we've had a company create a small board with just the vga out, power in and programming port. All other I/O's were eliminated but we kept all the rest of the components that came on the starter kit. Thanks.

potatohead · 2011-01-15 00:51

If it's a single message, I think I would use the VGA tile driver for it. You can author a image with the text attributes you want, convert it to binary data, to be included with your program image to be written to the EEPROM.

Seems like the Prop isn't doing much else but waiting to display it, which leaves lots of room for the image to be stored.

In my blog, I've linked the driver, and did some sample art. You get 64 colors to work from, and a resolution of 256x240 pixels to put it in. Many things, given there isn't a ton of detail, will easily fit into the HUB memory.

Your program then would just fire off that driver, two cogs only, no sprites are used, and when it's time to display the image, just write the tile-map address to the driver, so it will display.

The blog entry includes sprites. You can ignore those and just use the background.bmp as a working example of how to encode something for VGA display at a good resolution and color set.

The basic flow is author your message as a graphics .bmp file.

Then, save it.

Run the converter program Baggers wrote, and it will output two binary file packages. One will be all the unique tiles needed to display the image, and the other is a tilemap, which contains the screen addresses needed to tell the driver which tile to display where.

The sample program there contains the display code you will need.

This is one approach.

The other one is to use one of the VGA bitmap drivers, operate at a lower resolution, and simply author a bitmap in a graphics program to be displayed on the Propeller, skipping the tile map part of things.

dosmith · 2011-01-18 07:44

I'd like to give this a try. Can you point me to your blog? Thanks.

potatohead · 2011-01-18 07:56

Here's the entry here on the Parallax site. They gave us blogs!

http://forums.parallax.com/entry.php?76-Some-tile-art...

In that post, I've got the VGA / TV tile driver that does lots of colors. It's set for demoboard. Basically, you can make a 256x200 image for TV, then use the converter utility on it to generate tiles and a map file, which that driver can then display on the screen. The intent behind that is for games. I'm chipping away at one using the art sample on the blog. But, it doesn't have to be games. Look closely at the background.bmp It's formatted for VGA, as it has 240 lines. It can work on TV, just that not all of them will be seen.

Text or image?

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