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Expand Inputs and Outputs on BS2 circuit ? 74HC165 and 74HC595 — Parallax Forums

Expand Inputs and Outputs on BS2 circuit ? 74HC165 and 74HC595

T&E EngineerT&E Engineer Posts: 1,396
edited 2005-10-25 22:44 in BASIC Stamp
I thought I saw someplace a circuit that showed how to BOTH expand the BS2 outputs AND BS2 inputs. I know that the Stampwork experiments show how to do each one separately but I saw somewheres a circuit and code showing how to do it all. Can someone point me in the right direction?

Comments

  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-10-25 16:56
    The 74 series 194 chip can do 4 bits of input and output to be serially shifted into/outof a BS, look at the spec sheet and here: http://phy-server.phy.queensu.ca/~phys333/Labs_03/333LabD3_03.doc

    Figure D3.3 shows how to connect them in cascade fashion to increase the number of bits on a serial channel.


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    ·1+1=10
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-10-25 17:19
    Couldn't seem to find it off-hand, but Jon Williams posted that circuit.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-10-25 22:44
    This is from StampWorks 2 (at the printer now), and it shows a safe way to connect both while using on four I/O pins.· There is a 4.7K resistor between the two (in the data line) that must be present for this to work.

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    Jon Williams
    Applications Engineer, Parallax
    EX25 - Mixed IO.jpg
    594 x 924 - 63K
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