Bilateral CMOS switching

Discussion in 'Embedded Systems and Microcontrollers' started by Shagas, Feb 20, 2014.

  1. Shagas

    Thread Starter Active Member

    May 13, 2013
    802
    74
    Hello

    I am prototyping an audio recording/playback project. I am planning to control an SD card and two cascaded SIPO shift registers both independantly with a single SPI from an Atmega 32. To avoid conflicts I want to implement some sort of switch between the two.
    Do I need something like this?
    I was initially planning to use AND gates but since I am going to need to read from the SD card aswell AND gates are out of the question since they are one-way only.
    The sd card is for recording the audio and the shift registers are going to be outputs to a "hand made" DAC accepting parralel inputs.
     
    Last edited: Feb 20, 2014
  2. Shagas

    Thread Starter Active Member

    May 13, 2013
    802
    74
    Oh nevermind... I just noticed there is a CS pin on the SD card breakoutboard :)
    I feel slightly embarrassed for making this thread lol
     
  3. tshuck

    Well-Known Member

    Oct 18, 2012
    3,531
    675
    Meh, don't worry about it. I was going to mention something about the chip select, but figured you wouldn't have missed that!:)

    Sometimes it takes asking a question with an obvious answer for the answer to become obvious.
     
  4. Shagas

    Thread Starter Active Member

    May 13, 2013
    802
    74
    Yeah I haven't worked with SPI for a long time so I completely forgot that it inherently supports multiple slaves on a single bus :)
     
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