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Code crashes if I touch SX-Key pins using 50MHz resonator — Parallax Forums

Code crashes if I touch SX-Key pins using 50MHz resonator

sstickelersstickeler Posts: 8
edited 2007-06-14 22:34 in General Discussion
Hi All,
I am running an SX-48 using a 50MHz resonator ( from Parallax ). The code seems to run ok as long as I don't accidentally touch the SX-Key programming connector. If I do, in most cases the code will crash or act weird. I have tried the HS1 and HS2 settings. I seem to touch this connector a lot when I hit the reset button [noparse]:)[/noparse].

Is it normal for the oscillator to be this sensitive? Is there any way to make it more resistant to this type of thing? One thing I haven't tried is the HS3 setting. I might try that tonight.

Thanks in advance for any help.
-Scott

Comments

  • Guenther DaubachGuenther Daubach Posts: 1,321
    edited 2007-06-14 20:29
    Patient to doctor: "Whenever I press here, it hurts". Doctor to patient: "Then don't press there..."

    Hey, the resonator is operating at 50 MHz. Your finger adds enough load (resistance but also capacity) for such a high frequency to stop oscillation when you touch the SX-Key connector. When you remove the finger again, oscillation may or may not start again - at least, this is what I experienced myself. Increasing the SX-internal oscillator driver gain (HS3) may help but it is not for sure. So you better follow the doctor's advise smile.gif .

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Greetings from Germany,

    G
  • sstickelersstickeler Posts: 8
    edited 2007-06-14 22:34
    I guess I will have to be coordinated in the future tongue.gif

    Thanks for letting me know it is normal.

    -Scott
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