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External crystal/resonators on SX tech board — Parallax Forums

External crystal/resonators on SX tech board

Henry CassonHenry Casson Posts: 12
edited 2007-03-03 03:03 in General Discussion
The SX tech kit comes with two little three legged doohickies. Where are these documented?
I want ultimately to make a free standing device with an Sx28 and a 32 Khz watch type crystal. Where is this documented?

Comments

  • BeanBean Posts: 8,129
    edited 2007-03-02 20:16
    Those are ceramic resonators. I think the kit comes with a 4MHz and a 50MHz.
    If you don't need exact timing the SX can run at 32KHz, 128KHz, 1MHz and 4MHz from it's internal oscillator.
    If you DO need exact timing then the SX can be run from a 32.768 KHz watch xtal. You will probably need a capacitor on each side of the xtal to ground to get it to work properly.

    Bean.

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  • PJMontyPJMonty Posts: 983
    edited 2007-03-02 23:49
    Henry,

    Just to be clear, when Bean says if you DO need exact timing, one of the most common things he is referring to is asynchronous communication, such as RS-232. If your standalone device needs to communicate serially, it will need an external clock, crystal or resonator.

    Thanks,
    PeterM
  • Henry CassonHenry Casson Posts: 12
    edited 2007-03-03 03:03
    Thanks
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