Shop OBEX P1 Docs P2 Docs Learn Events
Musings: Composite to VGA conversion or VGA "forward"? — Parallax Forums

Musings: Composite to VGA conversion or VGA "forward"?

FlyingFishFingerFlyingFishFinger Posts: 461
edited 2009-11-17 03:32 in Propeller 1
I just got two of Ray's touchscreens for use in the UC Berkeley Solar car, but haven't gotten around to testing them. Its primary purpose will be for displaying information to the driver such as speed / GPS items / alarms etc. We also have a rearview camera on a separate screen. I just wanted to debunk a thought that came to mind: Would it be possible to eliminate the (composite) rearview screen by displaying its video on Ray's screen?
I don't know anything much about video, so this might be completely a completely ridiculous idea to begin with.
Just throwing it out there...

Rafael

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
You've got to play the game.
You can't win.
You can't break even, except on a very cold day.
It doesn't get that cold.
~Laws of Thermodynamics~

Comments

  • ericballericball Posts: 774
    edited 2009-11-17 02:46
    Not easily, no. Although the Propeller has a video generator (video output), it really doesn't have the I/O capabilities to digitize video (video input). If you had an external 8 bit ADC connected to pins 0-7 you could manage 5MHz sampling (~220 pixels across) to HUB RAM with a dedicated cog.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Composite NTSC sprite driver: Forum
    NTSC & PAL driver templates: ObEx Forum
    OnePinTVText driver: ObEx Forum
  • localrogerlocalroger Posts: 3,452
    edited 2009-11-17 02:49
    It's best not to think of the Prop in terms of real-time moving video, even though there are some apps that can do surpising things with that out there. The Prop just doesn't have the RAM to do a lot with bitmapped video. There is the video overlay thing but that's a bit of a hat trick since the Prop doesn't have to deal with the actual complex bitmap data; it just nudges the video signal in order to overlay text on whatever it's given. The Prop's video capabilities are really text based, despite what creative people have managed to stretch it to do, and getting anything out of the Prop other than text is what we in Louisiana call "lagniappe".
  • potatoheadpotatohead Posts: 10,261
    edited 2009-11-17 03:32
    Well, I wouldn't call the thing text based. IMHO, the best characterization is the graphics are software defined and dynamically generated as the Prop lacks higher level dedicated video circuts and functions.

    This is a good thing! We've seen a pretty broad set of capabilities brought to the chip, and also IMHO, there are things left to be exploited video wise.

    TV resolution bitmaps, moving objects and such are well within the appropriate expectations for Propeller graphics.

    The down side is having to work on code. The upside is that being software defined, we can expect to see a steady stream of video innovations on the thing over time. For a great example of how this works, just go check out some of the early Atari 2600 games, then go look at what was released this year and last! (yes, there are new game releases regularly) Software defined video systems end up doing an awful lot more than originally intended, because they benefit from grey matter applied to silicon over time.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Propeller Wiki: Share the coolness!
    Chat in real time with other Propellerheads on IRC #propeller @ freenode.net
    Safety Tip: Life is as good as YOU think it is!
Sign In or Register to comment.