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TV Aural 4th Pin? — Parallax Forums

TV Aural 4th Pin?

jazzedjazzed Posts: 11,803
edited 2009-05-02 23:37 in Propeller 1
Does the 4th pin ever become an output in any mode for TV.spin?
Thanks.

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--Steve


Propalyzer: Propeller PC Logic Analyzer
http://forums.parallax.com/showthread.php?p=788230

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2009-05-02 22:20
    You have to enable aural output for the 4th pin to become an output. See the tv_auralcog parameter to TV.spin.
  • jazzedjazzed Posts: 11,803
    edited 2009-05-02 22:32
    Hmm. Perhaps this is being filtered to "off" by the TV_Text.spin start method.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    --Steve


    Propalyzer: Propeller PC Logic Analyzer
    http://forums.parallax.com/showthread.php?p=788230
  • FrameShift.FrameShift. Posts: 35
    edited 2009-05-02 23:07
    what exactly is the aural broadcast? I've been wondering.

    -Tom
  • Mike GreenMike Green Posts: 23,101
    edited 2009-05-02 23:37
    Broadcast television includes audio. This is included by means of a frequency modulated subcarrier centered at 4.5MHz from the video center frequency. The Propeller's video generator can produce a broadcast video signal and has provisions for an FM subcarrier. This requires another cog that produces the 4.5MHz subcarrier with any audio modulation needed being left "as an exercise".
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