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Another P2 Question — Parallax Forums

Another P2 Question

I'm probly gonna drive y'all crazy with my questions. On my P2 Edge module (Rev.B), on the component side there is a teeny 5 position dip switch. Can I ask what those switches do or are they simply magical stuff for the Wizards of Parallaxia. :-)
I mean I kinda feel like Fargo on Eureka...

Anyhow, Thanks for any wisdom!!!

Amanda

Comments

  • JonnyMacJonnyMac Posts: 8,998
    edited 2024-05-07 23:53

    For setting boot options of the P2. From the P2 Eval schematic document:

    The USB RES switch allows the DTR signal to reset the board -- needed for serial programming. I think the default switch arrangement is ON-ON-OFF-OFF (all my boards are set that way).

  • @ajward said:
    I'm probly gonna drive y'all crazy with my questions. On my P2 Edge module (Rev.B), on the component side there is a teeny 5 position dip switch. Can I ask what those switches do or are they simply magical stuff for the Wizards of Parallaxia. :-)
    I mean I kinda feel like Fargo on Eureka...

    Anyhow, Thanks for any wisdom!!!

    Amanda

    There is a 4 position DIP switch, here is a description of those switches:

    6. Mode Selection Switch Bank
    This bank of dip switches controls the LED power and Boot Mode Selection functions. The dip
    switches are not set to any particular state on a new Edge module, although the four switches
    will all usually be set to the OFF position.

    Note: I've noticed that the switches usually are set with the first two up and the last two are down on the ones I've received.

    LED Power Control (On board LEDs enable)
    This switch controls power to two onboard LEDs, labelled and connected to I/Os P56 and P57.
    Switch ON to enable the LEDs. Switch OFF to disable the LEDs.

    Boot Mode Selection
    Upon startup or after reset, the Propeller 2 will always proceed according to the boot mode
    selection table shown below. The three switches labelled Flash, △ and ▽ are used to select the
    Boot Mode, and the options include booting (loading code) from USB-Serial, SD card or SPI
    Flash memory.

    Tip: △ and ▽ are both connected to the Propeller 2 I/O pin P59; one with a pull-up resistor to
    3.3V, and the other with a pull-down resistor to GND. You may see these boot mode selection
    pins referred to in other documentation as P59 up and P59 down.
    Important! To avoid inconsistent behavior, only switch one of the △ or ▽ dip-switches ON.
    Boot Mode Selection FLASH △ ▽

  • ajwardajward Posts: 1,129

    Excellent information guys! Thanks. With that knowledge it'll be "many moons" before I find a reason to change one of them.
    Oh my bad... on closer inspection it appears the switch is indeed a 4 position. I'm old and my eyes are tired! That's my excuse an' I'm sticking to it!
    Thanks again for the quick responses!

    Amanda

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