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VGA Breakout Adapter w/resistor color fix — Parallax Forums

VGA Breakout Adapter w/resistor color fix

Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
edited 2012-07-31 20:39 in Propeller 1
I'm considering doing a run of these... Thoughts?

VGA_BREAKOUT.jpg


Jeff
VGA_BREAKOUT.jpg
550 x 439 - 74K

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-07-31 19:47
    There's a layer missing from the image. Can you post a schematic, too, please? 'Wanna check those resistors! :)

    -Phil
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2012-07-31 19:53
    I pretty much drew this from scratch in the PCB editor (it's the same layout at the new VGA+ boards)

    Here's the circuit I'm using...

    VGA_BREAKOUT_SCM.jpg
    VGA_BREAKOUT_SCM.jpg
    440 x 343 - 23K
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-07-31 20:39
    Jeff,

    A better set of values would be 240 and 510 for the DAC series resistors, and 130 to ground. This accounts for the Prop's internal 27-ohm resistance. But try it first and measure the output on a scope to make sure it peaks at 0.7V with a 75-ohm load

    -Phil
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