View Full Version : TV to VGA conversion?

Michael T
01-31-2008, 04:24 AM
Any Help Would be greatly appreciated.

I'm new to propeller chip and·I·am using the folowing OBJ files: "tv_drv_010.spin","graphics_drv_010.spin" and "pause.spin" it is driving a 3.5" NTSC display and a button. Works the way I need it to as of right now. Power on "Stand By" Screen, button press, next screen, etc..

Now the problem is they want to change it to a·3.5" VGA 640 x 480·Display.·Getting the·NTSC Display to work took me a while because I really have NO experience with the Propeller. But reading and fiddling around with stuff I got that one to work.

So Bottom Line is I need to convert what I have to run on a VGA monitor and I am running out of time. Thanks Michael

01-31-2008, 04:57 AM
The TV and VGA drivers are ,"for the most part", swapable. The calls are the same I mean.
The hardware is the main difference. Look at the schematic for the demo board. Once you have the circuit, the existing software you have is just fine! "aside from changing you object reference to VGA instead of TV"

As an Example; Download the Sensirion demo from the OBEX.
In the main routine you'll see that by commenting out TV the App uses VGA, By commenting out VGA, the App uses TV.

Post Edited (bambino) : 1/30/2008 10:03:32 PM GMT

01-31-2008, 05:16 AM
According to the names of the drivers you use the Hydra; note that the pin groups for VGA also differ between Hydra and more common boards.

Michael T
01-31-2008, 05:45 AM
I am using some of the hydra code: I have it running on a proto board. the ntsc out is usingpins 24,25,26. Is the changing of the pins something I would have to do in the assembly portion of the code? I am downloading the Sensirion demo now and I will look at that. Thanks for your help.

Have the sensirion Program running on the the vga now after a little tweaking. I guess the other question is how to Change and or have different size text on the display at one time.

Post Edited (Michael T) : 1/31/2008 12:58:55 AM GMT

01-31-2008, 08:24 PM
The only easy way to have a different sized text on the screen at the same time is to use Graphics.spin. It uses a lot of memory, but you can define several small graphics areas to hold the text.

Another alternative might be to define your own 16x16 font that would be the same width but half the height of the ROM font.

Michael T
01-31-2008, 10:18 PM
That is beyond my scope of Propeller knowledge. Is there some code I could look at that would be a great starting point for writing to the Screen. At this point I would need to draw three different screens that I can cycle through with a button press, which I have working on the NTSC Using the Internal Font allowing you to change the character scaling for each.

01-31-2008, 11:03 PM
Look here:


At my "Delay Generator Demo" for one way to have a GUI...
Also, I have notes at the bottom on how to make a smaller Graphics area anywhere on the screen...

But, this is all for XGA mode (1024x768).· Sounds like you would want to adapt this for the VGA driver...

01-31-2008, 11:04 PM
Also, I posted a Blackjack game there in both VGA and TV with basically the same code. But, again I had to use the XGA driver...

Michael T
01-31-2008, 11:33 PM
yes I would need it to be 640x480. Thanks for the link I'll check it out. This is the link for the monitor.


Michael T
02-02-2008, 11:21 AM
"Props" to deSilva Thanks for the guidance. It works like a champ. Michael