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Gimzo 2 custom On/Off button?

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Ideally I'd want to modify the BIOS to autostart without pressing any button. But if nobody ends up knowing how to do that, I'd like to at least have a custom proper button on my device's case for turning the Gizmo on. I've read one of the pin pairs can be used, but which ones?

 

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    Hi Mark,

     

    The information is in this thread: http://www.element14.com/community/community/designcenter/single-board-computers/gizmo2/blog/2015/07/30/gizmo2--flash-bios-to-autostart-on-power-up .

    In summary you can either solder your custom switch directly across the switch on the circuit board (not ideal) or access the same connections on a PCIe connector or use the debug connector which

    is probably easiest (this is all in the schematic PDF doc).

    You can see in the PDF in the page 3 block diagram that the power button circuit is on page 21 in the PDF, and that the relevant signal is called PWR_BTN and that it is connects to ground via a 10 ohm resistor.

    So you'll need an external switch and a 10 ohm resistor in series.

    By doing Ctrl-F and searching for the text 'PWR_BTN' in the PDF, you'll see that the signal is brought out to the debug connector marked J13, pin 10.

    You can use pin 15 as the ground end of the switch. Pin 1 of the debug connector will be indicated with a square shaped pad, and the pin numbering is in a zig-zag fashion as shown in the

    schematic (I don't have a Gizmo2 near me to confirm with a multimeter, but you could easily confirm by putting one end on pin 10, and the other at the power button on the board, and you should measure

    10 ohms resistance.

  • 0 in reply to shabaz

    I'm more a programmer and the schematics are a bit confusing. I understood the part about connecting a button and 10 Ohm resistor in series, but not which pin to which pin (yes I prefer the pins over soldering on the PCIe or across the stock button).

    Sorry. I didn't expect to do have to do any hardware mods for something this trivial, but luckily it seems the only hardware modification I'll be doing.

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  • 0 in reply to shabaz

    I'm more a programmer and the schematics are a bit confusing. I understood the part about connecting a button and 10 Ohm resistor in series, but not which pin to which pin (yes I prefer the pins over soldering on the PCIe or across the stock button).

    Sorry. I didn't expect to do have to do any hardware mods for something this trivial, but luckily it seems the only hardware modification I'll be doing.

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