Shop OBEX P1 Docs P2 Docs Learn Events
Pull down network... Why doesn't it make sense... — Parallax Forums

Pull down network... Why doesn't it make sense...

Kaos KiddKaos Kidd Posts: 614
edited 2006-08-15 16:43 in General Discussion
I'm trying my hardest to see how this works... and for some reason, I just cant see it.
What I need is either a logic HI or LOW (IE Not floating) on the inputs to the PCF8574.
So, all the resistors have one end tied to ground...
The other end goes through the DIP switch... which goes into the inputs of the PCS8574.
Ok, no problem here.· Now, if I tie all the inputs to the PCF8574 to HI, will they all appear as HI no matter what the position the DIP is in?
Tieing the inputs to GND doesn't seem to work either, so I've either missed the boat completly... or...
Well, I won't consider the or here... please point out my wiring error...



attachment.php?attachmentid=42893

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔

Propeller + Hardware - extra bits for the bit bucket =· 1 Coffeeless KaosKidd
518 x 792 - 20K

Comments

  • Paul BakerPaul Baker Posts: 6,351
    edited 2006-08-15 16:23
    You have the resistors on the wrong side of the switch, they must be on the output side of the switch:

    ^ Vdd
    |
    +-- S -+-- Out
           |
           R
           |
           V Gnd
    



    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ...
  • Kaos KiddKaos Kidd Posts: 614
    edited 2006-08-15 16:26
    Thanks Paul...
    (This thread should be moved shortly... it's off topic... I wasnt paying attention when posting... sorry guys...)

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔

    Propeller + Hardware - extra bits for the bit bucket =· 1 Coffeeless KaosKidd

    ·
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-08-15 16:43
    This thread is being moved from the·Propeller Chip·Forum to the·Sandbox Forum.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
Sign In or Register to comment.