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TV_text and the spin stamp — Parallax Forums

TV_text and the spin stamp

Rob7Rob7 Posts: 275
edited 2007-06-12 22:59 in Propeller 1
Gent's
I have just received my spin stamp and board of education. I have made the corrections to the spin code, but I cannot see any text ! I have a blue screen though.
I added _clkmode=xtal1+pll8
·········· _xinfreq=10_000_000
P0 resistor 1.2 k
P1 resistor 560
P2 resistor 270

Has anybody had this problem ?
I am new to spin and am trying to understand the code.

I have attached the spin code I am useing.

Comments

  • Paul BakerPaul Baker Posts: 6,351
    edited 2007-06-11 23:58
    That is just the driver, you need a top level file which directs the driver what to display, check out Examples\Library\TV_Text_Demo.spin for an example top level file for that object.

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • Rob7Rob7 Posts: 275
    edited 2007-06-12 00:28
    Thanks, Paul
    O.K. now I feel real stupid.
    I will try that, I should have completed all of the PEK labs first ! Objects are my next chapter.
    Thanks again
    Rob7
  • W9MASW9MAS Posts: 17
    edited 2007-06-12 02:21
    I have the same problem with the TV Text composite signal. Most of the time I get some text but it's not right. Behaves irratic. If I reset, I sometimes get blue screen or nothing at all. I'm using an ATI HDTV card in my PC for a display.

    It work's perfectly on a regular TV set!

    Almost looks like an overdriven signal (>1V P-P) or something. I included a pic.
    Test.jpg
    382 x 376 - 19K
  • Paul BakerPaul Baker Posts: 6,351
    edited 2007-06-12 02:30
    It's hard to tell whats going on with the apparently blank screen you've captured.

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • W9MASW9MAS Posts: 17
    edited 2007-06-12 02:33
    UPDATE

    I read Paul Baker's reply. I downloaded the TV Text Demo and that works perfect on my Proto Board. (Note: I scratch built the circuitry to morph my Proto board into a Demo board.)

    Any ideas?
  • W9MASW9MAS Posts: 17
    edited 2007-06-12 02:36
    Paul:

    Disregard the image I attached.·The capture didn't·work. What I get is a really bright, washed out·text and background, other times blue or black.
  • Paul BakerPaul Baker Posts: 6,351
    edited 2007-06-12 02:37
    Im having a little difficulty following you, you have a ProtoBoard in which you built up a RCA plug and you can run TV_Text_Demo, it runs on a TV but not your TV card?

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • W9MASW9MAS Posts: 17
    edited 2007-06-12 02:41
    Partially correct. Been experimenting as I write. The TV Display program example from the Propeller Tutorial Chapter 3 gives the results I described in my first message. On a regular TV it works fine.

    The TV Text Demo works fine on composite inputs to a regular TV and my ATI PC TV card.
  • W9MASW9MAS Posts: 17
    edited 2007-06-12 02:45
    By the way, I am new to the Prop products and am very impressed with the VGA display quality. Really fantastic!
  • Paul BakerPaul Baker Posts: 6,351
    edited 2007-06-12 02:50
    I dont know which code you are refering to, which tutorial?

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • W9MASW9MAS Posts: 17
    edited 2007-06-12 03:05
    Paul,

    I'm following the The WebPM-v1.01.pdf book. Chapter 3.· See pic.

    Thanks for the help!
    Screen Capture.jpg
    861 x 583 - 120K
  • W9MASW9MAS Posts: 17
    edited 2007-06-12 03:08
    Oops. . .The correct name of the application is Display.Spin, located in the Prop Tool program folder.
  • Paul BakerPaul Baker Posts: 6,351
    edited 2007-06-12 03:15
    Gotcha, I cant look at the output until Im back at work. Im thinking that there are some supersaturated colors being used and the TV card is freaking out because of it. Try running the Graphics_Palette.spin in Examples/Library, and tell me if you get similiar "freaking out" on the top of the display.

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • W9MASW9MAS Posts: 17
    edited 2007-06-12 03:27
    Yep, that's kind of what I suspect. Since it's B & W text, the peak to peak signal voltage could be overdriving the TV card composite input. Anyhow, many thanks and appreciate the help! Will try your suggestion and let ya know.
  • Paul BakerPaul Baker Posts: 6,351
    edited 2007-06-12 03:29
    Yeah, the high contrast can cause ghosting and other issues even on regular TVs, but TV cards are more susceptable to it.

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • Rob7Rob7 Posts: 275
    edited 2007-06-12 06:24
    Paul,
    Not to get off the subject with W9MAS, I got it working ! Great job. Thanks for the help.
    W9MAS, hope you get yours working.
    I attached the code for the Spin stamp, TV terminal and TV text.
    Rob7

    Post Edited (Rob7) : 6/12/2007 6:30:04 AM GMT
    spin
    spin
    TV_TerminalSpinstamp.spin
    6K
    spin
    spin
    TV_TextSpinStamp.spin
    6K
  • Rob7Rob7 Posts: 275
    edited 2007-06-12 16:07
    For the newbie's like me. I attached the GraphicsDemoSpinStamp code here. Attach your RCA jack to resistors starting at
    pin 0 1.2k
    pin 1 560
    pin 2 270
    Have fun !
    Rob7
    spin
    spin
    Graphics_DemoSpinStamp.spin
    8K
  • KaioKaio Posts: 253
    edited 2007-06-12 18:18
    Why did you not use the original pins (12 - 14) used on Demo board? Then you would not have to change the code of the TV driver. And you could be using the SD-card driver also unchanged.
  • W9MASW9MAS Posts: 17
    edited 2007-06-12 18:33
    Paul:

    The Graphics_Pallette and Graphics_Demo produce the same negative results. Through experimentation, I can get a better display by varying the resistor value on pin 12 to something lower.
  • Rob7Rob7 Posts: 275
    edited 2007-06-12 20:27
    Good question ?
    I need to play with the program and learn how it works, then make it simple. To a newbie, simple is best. I am still learning how spin code works.
    Rob7
  • Paul BakerPaul Baker Posts: 6,351
    edited 2007-06-12 21:12
    W9MAS said...

    Paul:

    The Graphics_Pallette and Graphics_Demo produce the same negative results. Through experimentation, I can get a better display by varying the resistor value on pin 12 to something lower.

    This probably means that the signal is over driven, or there is an impedance mismatch causing an overshoot of the voltage. As you've noticed reducing the values will help.

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • W9MASW9MAS Posts: 17
    edited 2007-06-12 22:59
    Problem resolved.

    Substitued trimmers for resistor network and adjusted for best picture quality. TV PC card is much more sensitive to variations in sync pulse amplitude than conventional television.
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