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? on Propeller Project Board schematic — Parallax Forums

? on Propeller Project Board schematic

AGCBAGCB Posts: 330
in Propeller 1

I don't understand this. I know P1, P2 are the propeller pins on the board but what the heck are P161, P162 etc?
I'm wanting to hook up a VGA connector.

Aaron

Comments

  • VonSzarvasVonSzarvas Posts: 3,486

    Could you share a link to the schematic you’re looking at?

  • AGCBAGCB Posts: 330

    I got it as a download. I don't have a link.

    Search for Propeller Project Board schematic.

    Aaron

  • Francis BauerFrancis Bauer Posts: 369

    @VonSzarvas said:
    Could you share a link to the schematic you’re looking at?

    I believe @AGCB is referring to the schematic for the 32810 Propeller Project Board, which I've attached.

    The VGA part of the schematic for example references P3 for connecting to the 240 ohm VGA Red input and P161 for the 510 ohm VGA Red input. The question is where do you find P161 on the board? Is it the designation of one of the many thru holes on the board? Perhaps one of the holes pointed to by the R silk screen on the board?

    I've also attached a copy of the 32810 Board guide PDF, which has annotated images of the project board. I think the confusion is that there aren't any visual references on the annotated images showing where these high numbered "pins/holes" like P161 are located or at least some kind of description of what they are.

    PDF
    PDF
    32810-Propeller-Project-Board-Schematic-Rev-C-D.PDF
    1M
    pdf
    pdf
    32810-Propeller-Project-Board-USB-Guide-v3.1.pdf
    1M
  • AGCBAGCB Posts: 330

    Francis
    That's correct. I guess I'm going to do it as I've done before which amounts to this, using 8 consecutive pins.
    Thanks
    Aaron

    • it is suggested that:
      '' bits/pins 7..6 are used for red
      '' bits/pins 5..4 are used for green
      '' bits/pins 3..2 are used for blue
      '' for each bit/pin set, sum 240 and 470-ohm resistors to form 75-ohm 1V signals
      '' connect signal sets to RED, GREEN, and BLUE on VGA connector
      '' always connect group pin 1 to HSYNC on VGA connector via 240-ohm resistor
      '' always connect group pin 0 to VSYNC on VGA connector via 240-ohm resistor
  • VonSzarvasVonSzarvas Posts: 3,486

    Thanks Francis.

    I'm not familiar with that board, but it looks to me like anything labelled P0 to P31 connects somehow to the Propeller.
    Whereas anything with a larger P number (such as P161) is just a node that the user can solder to.

    I can see something similar in the LDO 8-pin bridge output. All those pins labelled P16x are just connected to themselves (bridge) - for the user to solder onto if they want to.

    So high numbered pins are for user choices/connections. Low numbered P0-P31 are the Propeller I/Os.

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