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Propeller QuickStart tv_text — Parallax Forums

Propeller QuickStart tv_text

libadmanlibadman Posts: 36
edited 2022-11-04 17:45 in Propeller 1

Hello to all!!! My name is Mike and I used to used this forum when I was more active with parallax products, now that I am once more I’ve forgotten some things and need to learn a few. My issue is I’m trying to get started with video from the propeller so I use tv_text demo because in the past I’ve used it and got it to work. I connect the 3 resistors to each other and to the respective pins then to a rca cable, I also ground the rca cable to the propeller. But no video- the 1.1k resistor I did sub with another value but I forget what I used I’m not home rn. I’ve tried changing the value to get close to 1.1k as I can. I live in Tampa and can’t find this resistor anywhere not even in Orlando. I was gonna try vga but with this not working and me not knowing why I rather stick with the basics. I also like to mentioned I used pins 12/13/14 on the propeller I have no ideal how to change the basepins because I do not understand the code clearly, but the base pins in the demo are suppose to be 12/13/14. Any help would be great. Thanks I’m advance.

Comments

  • You can use the formula (Rtotal = R1 + R2 +R3...) for series resistors. 1 kilohm resistors and 100 ohm resistors are both very common. One of each in series would equal 1.1 kilohm.

    Paul

  • The exact value of the resistors doesn't matter. As long as they're very roughly correct, you'll get something on screen. Not that the P1 video output is particularly Hi-Fi to begin with.

    • Are you sure the resistors are in the right order?
    • Are you sure that the monitor you're using works?
    • Do you have an oscilloscope available?
  • AGCBAGCB Posts: 307

    Here's what I use

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,493
    edited 2022-11-06 21:35

    Here's what I use:

    It preserves the 75-ohm source impedance.

    -Phil

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