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Quickstart VGA socket ? — Parallax Forums

Quickstart VGA socket ?

AGCBAGCB Posts: 327
edited 2013-12-26 11:43 in Propeller 1
Hi
I'm trying to add a VGA socket to my Quickstart board and I have determined all the pin routing except the pin 9 on the VGA socket. One schematic shows it tied to 5V and another to ground. Which should it be? I'm allergic to smoke, especially expensive smoke!
Thanks
Aaron

Comments

  • TubularTubular Posts: 4,703
    edited 2013-12-25 09:45
    You can leave it unconnected as its often the "key" or absent pin on many vga cables. Officially I think its 5v (i've never seen a circuit with it grounded)
  • AGCBAGCB Posts: 327
    edited 2013-12-25 09:51
    Tubular wrote: »
    You can leave it unconnected as its often the "key" or absent pin on many vga cables. Officially I think its 5v (i've never seen a circuit with it grounded)

    Thanks
    Aaron
  • Toby SeckshundToby Seckshund Posts: 2,027
    edited 2013-12-25 11:20
    The pin 9 of the VGA should be connected to +5V, or left open circuit.It is there as a way of powering up things from the host PC.

    On a PC (etc) the +5V is used to power up a EEPROM in the VGA monitor, SDA and SCL go down pins 12 and 15. This allows the PC to know what the monitor is even if it is un-powered. Obviously the Prop doesn't do any of that.

    Some connectors do a lazy thing and just connect all of the middle row to deck, great until something that has the +5v on pin 9 gets plugged to it ! A lot of connectors/leads have that pin missing to prevent problems.

    I tend to leave it O/C on the Prop boards, but it could be useful as a way to get +5V off the board for external things, for that I usually pick it off of a PS2 Keyboard connection if there is one.

    Alan


    PS Merry Christmas to all
  • AGCBAGCB Posts: 327
    edited 2013-12-25 11:51
    [QUOTE= a PS2 Keyboard connection if there is one.
    [/QUOTE]

    Speaking of PS/2, that's the next thing I want to add. I assume just the clock and data pins and the ground for a mouse and keyboard. Is that right? I have both a mouse and keyboard that I want to connect to the Quickstart.
    Thanks again
    Aaron and Merry Christmas from here too!
  • TubularTubular Posts: 4,703
    edited 2013-12-25 18:47
    And +5v too for PS2 devices.
  • AGCBAGCB Posts: 327
    edited 2013-12-26 05:11
    I was wondering about that. Thanks for the confirmation.
    Aaron

    edit: since it's 5V, does there need to be input protection for the Prop? series resistor or?
  • max72max72 Posts: 1,155
    edited 2013-12-26 07:47
    The demo board has ps2 connectors, and the schematic is in the propeller tool.
    I would start from that.
    Massimo
  • Toby SeckshundToby Seckshund Posts: 2,027
    edited 2013-12-26 11:25
    Most of the Prop boards I have put together have been shameless variants of the DemoBoard schematic. The DracBlade board by DrAcula is a good example of what you can add onto a DemoBoard.
  • AGCBAGCB Posts: 327
    edited 2013-12-26 11:43
    Thanks
    Aaron
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