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Detecting multiple inputs — Parallax Forums

Detecting multiple inputs

alnajjar1alnajjar1 Posts: 110
edited 2013-04-28 10:33 in BASIC Stamp
Hello,

Anyone knows of an equivalent IC to the 74HC165 to detect logic 1 and 0 instead of switches? I have 12 touch sensors that give me TTL voltage (about 3.4V) and I don't have enough IOs on the BS2.

thanks,
Al

Comments

  • PJAllenPJAllen Banned Posts: 5,065
    edited 2013-04-28 06:24
    http://www.parallax.com/dl/docs/books/sw/exp/sw24b.pdf
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2013-04-28 06:28
    Or are you saying that 3.4V isn't good enough as an input-High?
  • Hal AlbachHal Albach Posts: 747
    edited 2013-04-28 06:54
    If you have room in program store for I2C then you could use 2 Phillips PCF8574 I2C remote port expanders. A bonus feature is that anytime one of the inputs changes state the chip fires an interrupt signal which the stamp could easily monitor. Subsequent reading of the chip resets the interrupt line. If you go to a BS2P then I2c is built in along with several other features. While at it, a BS2P40 will give you 16 additional I/O lines.
  • alnajjar1alnajjar1 Posts: 110
    edited 2013-04-28 10:33
    I am a bit embarrassed. I just realized that I can go directly to the 165 and remove the switch-resistor combo at the input provided a have good logic levels which I do.

    many thanks,
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