Shop OBEX P1 Docs P2 Docs Learn Events
Propeller as composite video driver — Parallax Forums

Propeller as composite video driver

softexsoftex Posts: 27
edited 2009-01-20 02:42 in Propeller 1
Hello all,

I have a rather large application running on a PIC 18LF2620 and would like to output text serial video strings to the propeller for video processing. There I figure to tweak the video software a bit to jazz up the text display - like double-sized (or larger) fonts, etc. Basically, I propose to use the propeller strictly as a composite text video driver for this PROTON BASIC app running on a PIC, instead of using my EZVid (www.multilabs.net) serial video generator add-on board (great product, but way too expensive for production). As ever, when it comes to this stuff, I know just enough to be dangerous - and no more. I can generally get results if pushed in the right direction so ... Has anybody here tried something like this? Or is it just a stupid idea? Any help/advice greatly appreciated.

-Dave

Comments

  • jazzedjazzed Posts: 11,803
    edited 2009-01-19 20:35
    Someone got honorable mention in a Parallax contest for using Propeller as a peripheral device connected to a 6502.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    --Steve
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2009-01-19 21:16
    Looking at the ezVID, you can almost do the same thing with the terminal software here.
    (Grab the first download link. PropCOMM2_ascii)

    The difference being that it doesn't handle text like a bitmap, but the display package
    allows redefinition of characters on the fly, so basic graphics be created with the text.

    It could be adapted easily for various display functions.

    OBC

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    New to the Propeller?

    Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
    Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
    Got an SD card connected? - PropDOS
  • LeonLeon Posts: 7,620
    edited 2009-01-19 21:23
    A CPLD and RAM could be used, and might be cheaper.

    Leon

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Amateur radio callsign: G1HSM
    Suzuki SV1000S motorcycle
  • softexsoftex Posts: 27
    edited 2009-01-19 23:02
    Thanks, I just got a proto board and havn't done much with it yet. From what I've read, I just might be able to manage to customize the spin code in the various driver variations that seem to be available, including the one mentioned above. If I come up with anything useful I'll post it. Programming a CPLD is way above my pay grade - besides, it would be nice to port the entire app over to the propeller[noparse][[/noparse]2?] at some point in the future. Anything I should be aware of when interfacing the PIC with the propeller?

    -Dave
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2009-01-19 23:12
    Just that the Propeller is a 3v chip. Nothing that a resistor or two can't solve.

    OBC

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    New to the Propeller?

    Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
    Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
    Got an SD card connected? - PropDOS
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-01-19 23:18
    If you can run the PIC at 3.3V, that would help to simplify the interface to the Propeller.

    BTW, I think you'll be happy with the current consumption of the Propeller and its ease of programming, compared to a CPLD. (I'd hate to have to configure an NTSC driver with programmable logic.)

    -Phil
  • Cluso99Cluso99 Posts: 18,069
    edited 2009-01-20 01:21
    The Prop is the way to go. If you later decide to use VGA instead, you basically only have to change the object from TV to VGA. As OBC said above, he has basically done all of this already smile.gif

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Prop Tools under Development or Completed (Index)
    http://forums.parallax.com/showthread.php?p=753439

    My cruising website http://www.bluemagic.biz
  • parts-man73parts-man73 Posts: 830
    edited 2009-01-20 02:42
    Why not ditch the PIC altogether and fit it all inside the Propeller. After the TV object, you'll still have plenty of room left over for the code that the PIC is currently running.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Brian

    uController.com - home of SpinStudio - the modular Development system for the Propeller

    PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!

    SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board
Sign In or Register to comment.