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Hackable Badge and wrong polarity (#20100) — Parallax Forums

Hackable Badge and wrong polarity (#20100)

BartintoshBartintosh Posts: 6
in General Discussion
Hi there,

not awaken this morning.. put the the battery the wrong side.. run to remove it but the badge seems dead already (at least power ON button)
He still can charge, can startup (don't ask me why, but he did once, run firmware.. fine..) but he did not answer the power ON button 99% of the time.

What did I fried? can he be saved from the recycle bin?

Thanks! ):

Vincent

Comments

  • VonSzarvasVonSzarvas Posts: 3,450
    edited 2018-11-02 10:03
    With battery inserted the correct way, try momentarily touching a wire between two pads near the bottom right of the Badge.

    One is marked "bP", the other VBATT

    Does that power up the badge and get things working ?
    HEB_Pwr_MOD.png
    1847 x 1384 - 181K
  • BartintoshBartintosh Posts: 6
    Hi,

    yep, he "boot" but turns OFF as I release the bridge..
    But funny it booted once when I tryed powering ON and worked till I powered OFF again.
  • VonSzarvasVonSzarvas Posts: 3,450
    edited 2018-11-02 14:27
    Sounds like the switch controller has blown, highlighted in the attached img.

    Dual inverting Schmitt trigger, SOT-363
    74LVC2G14

    Some ideas...
    Replace the blown part
    Add a manual switch across the bridge wire contacts
    Fix the wire bridge permanently and remove the battery when not using the device.
    HEB_Pwr_FlipFlop.png
    1366 x 1067 - 125K
  • BartintoshBartintosh Posts: 6
    I vote for the replacement, but I must get a fine tip.. mine would be too large for such surgery..
    By the way, I've found where to "touch" to make it work using the switch.. but this is weird and must be fixed anyhow.
    Thanks a lot for that quick diagnostic :)
  • PublisonPublison Posts: 12,366
    @Bartintosh,

    Welcome to the forums!

    You were lucky to get the attention of one of the designers! And he is in the same time zone as you. :)
  • Buck RogersBuck Rogers Posts: 2,185
    Second the motion!
    VonSzarvas I did not know that important bit of trivia about you. Oh and mine says "HELLO!". I wear it during Hack A Day NYC events to see who notices it. Answer very few sadly.

    And you sir(?) will find truly amazing and helpful, also talented people in here.
  • BartintoshBartintosh Posts: 6
    Yes, can't expect better answer really :)
  • BartintoshBartintosh Posts: 6
    Hm... maybe one more question regarding the SOT-363 swap.
    New chips seems to have a white point painted on the top, as chip sens matter probably (I'm newbie).. is there any way for me to detect the way/sens to place the new chip? Thanks :)

  • VonSzarvasVonSzarvas Posts: 3,450
    Pin 1 is marked with a little dot. It's not so easy to spot (ahem!), so here's a zoomed in image, with the mouse hand hovering over the pin-1 dot.

    If the new part has some other marking, just check the datasheet for how that relates to pin1 and you'll be good.

    If it's a slightly different version (part-number) or manufacturer, do make sure the pin order and functionality in both datasheets match. There's a whole range of these buffers, and there'll be subtle differences, like inverted vs non-inverted, open drain vs push-pull. Sorry if I'm stating the obvious, but as you mentioned the marking differences I figured better to be sure anyone in the future doesn't get stuck on these little details.
    HEB_FlipFlop_Orientation.png
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  • BartintoshBartintosh Posts: 6
    True, I saw a lot of different one.. Is this one from Nexperia?

    Additional tech background inputs are welcome by everyone I'm sure :)
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