Docs for P9-9 and P9-10

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1

Can somebody point me in the direction of docs for the use of P9-9 (pwr_but) and P9-10 (sys_resetn)? I’d like to bring the power button out to a panel mounted momentary switch. I’ve set up a button with a 1k pulldown like you would normally do with a GPIO pin but that doesn’t seem to be working.

2

Did you look on the Support WIKI?

http://www.elinux.org/Beagleboard:BeagleBoneBlack

Gerald

3

Thanks Gerald… sometimes I just need a push.

I did search the Wiki but didn’t find any references about how to hook up to those pins. (So my assumption was to treat them like the GPIO pins.)

However you prompted me to tray again and searching on the term ‘pwr_but’ I can now see that the Battery cape implements a power button. The schematic shows it shorting to ground. Makes sense. I’ll give that a try.

4

It is in the System Reference Manual. How you hook them up depends on which of the pin mux options you plan to use and the resulting mode of operation.

Gerald

5

Ah, I see it now. I searched on P9.9 and missed the reference to pwr_but. I’m pasting it in here in case somebody else searches the forums in the future:

“PWR_BUT is a 5V level as pulled up internally by the TPS65217C. It is activated by pulling the signal to GND.”