Shop OBEX P1 Docs P2 Docs Learn Events
Need help getting NTSC video output to work with Backpack — Parallax Forums

Need help getting NTSC video output to work with Backpack

DougworldDougworld Posts: 24
edited 2013-04-02 20:51 in Propeller 1
I can't get my NTSC video monitor to display the output of the demo program "PropBP_terminal_demo.bs2" as per the instructions in the Propeller Backpack V 1 manual. I plug the Backpack into my BASIC Stamp HomeWork Board and wire Pin 15 to the Backpack input, plus I add Vdd and Vss jumpers -- all according to the picture in the manual. The software compiles and downloads correctly.
I connect my trusty Parallax USB Oscilloscope to Pin 15 and I can see the demo program putting out nice signal. I hook channel 2 of the scope to the video output on the Backpack and there is no output signal. I tried both 1/8" mono and stereo connectors in the Backpack with no luck.
Does anyone have a clue how to diagnose and fix this? Thanks in advance.

Comments

  • Duane DegnDuane Degn Posts: 10,588
    edited 2013-04-02 20:51
    Do you have the jumpers set correctly? Page 23 of the manual shows how the "Vid" pins need to have a jumper connected to them. The "Ovl" doesn't need a jumper. I'm not sure if having one there would cause a problem or not but I'd suggest removing the jumper just in case (unless Phil says otherwise).

    You should use a stereo jack to connect to the Backpack. What's on the other end of your stereo jack? How are you connecting it to your NTSC monitor? The video signal is transmitted via the tip of the stereo jack. You can check with a multimeter to see which connector corresponds with the tip of the jack. This is the connector (on the other end of your adapter) to plug into your NTSC monitor. Most NTSC monitors I've seen use an RCA connector for the video signal. If you have a RCA connector on your monitor then you'll want to use the connector who's center pin is electrically connected to the tip of your 1/8" jack.

    I haven't used the Backpack as a display for another microcontroller myself so I'm not sure what needs to be done to get it to work. Are you sure the correct program is loaded in the Backpack?

    Do you happen to have a Prop Plug? It might make diagnosing the problem easier.

    Do you happen to have a Prop Plug? If so there are other tests you could do.
Sign In or Register to comment.