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Minimum hardware setup — Parallax Forums

Minimum hardware setup

HeadShotHeadShot Posts: 5
edited 2006-07-20 20:06 in Propeller 1
Looking at the schematics in the manual, for the demo board and PropStick, I'm trying to decide what my minimum breadboard setup is. 3.3 v is understandable, as in the MAX3232 for the TTL interface. But the EEPROM and crystal seem to be optional. Just for messing around, I don't think I need the extra memory and I thought the Prop had an internal clock. So 3.3 v., TTL interface and a 220/LED for a minimal test interface?

Dan

Comments

  • christopherchristopher Posts: 31
    edited 2006-07-20 17:01
    I would suggest that do use the crystal and the eeprom. There's just so much more flexibility as the xtal allows you with a single instruction to generate precise delays.

    Christopher
  • HarleyHarley Posts: 997
    edited 2006-07-20 17:02
    HeadShot wrote ---

    [noparse][[/noparse]quote].....But the EEPROM and crystal seem to be optional. Just for messing around, I don't think I need the extra memory and I thought the Prop had an internal clock. So 3.3 v., TTL interface and a 220/LED for a minimal test interface?


    idea.gif Are you sure you want to compile/download each time you power-ON again? Seems the price/space/wiring/etc involved is very worthwhile. It's just an 8-pin'er.

    This old guy's 2 pesos.

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    Harley Shanko
    h.a.s. designn
  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2006-07-20 18:41
    Dan,

    Just for messing around....

    The memory could be optional as long as you keep the Propeller alive with power.
    That said, you wouldn’t be able to run any applications that read or write to the memory.

    If you choose to use the internal RC oscillator instead of the crystal, you will not be able
    to run any applications that rely on the internal PLL.

    An alternative to using a crystal would be to use an inductor. See this thread...
    Parallax Forums > Public Forums > Propeller chip > Clock Speed accuracy
    ...This method would allow you to use PLL functions.

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.

    Post Edited (Beau Schwabe (Parallax)) : 7/20/2006 8:19:09 PM GMT
  • HeadShotHeadShot Posts: 5
    edited 2006-07-20 20:06
    Thanks. It looks like the short answer is: Yes.
    I understand that I would not be able to do much, but that's what I'm thinking with "minimal" turn on/off an LED.
    Thanks for the responses.

    Dan
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