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BS2 w/ MC74HC595 VS MC4094 — Parallax Forums

BS2 w/ MC74HC595 VS MC4094

wyrlesstekwyrlesstek Posts: 2
edited 2012-02-16 10:01 in BASIC Stamp
I built a irrigation circuit board tester using a BS2 OEM for control of the MC74HC595 on the board. The test turns all outputs off, then steps them, then all off, then all on, all off and repeat. All works well. I'm now trying to marry my tester with the next generation board which uses a MC4094 instead of the 74HC595. They seem like brothers with their pin names. I have activity on input pins, 5 volt supply, ouput enable held low, even activity on serial out (9+10). I don't have control of outputs. Do I have to rework my program for the 4094. If not, here is the possibility the used board provided is defective. Any help appreciated.

Comments

  • PJAllenPJAllen Banned Posts: 5,065
    edited 2012-02-15 19:03
    The '595 outputs are enabled with its OE low (it's /OE, active low.)
    The 4094 outputs are enabled with its OE high.
  • wyrlesstekwyrlesstek Posts: 2
    edited 2012-02-16 10:01
    Your right on the output enable, thank you.
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