sounds like you want to patch overo.h to change the default muxing (and pullup) of your pin.
Check out Scott Ellis' page:

Good luck,

From: Geoffrey Atkinson <>
To: General mailing list for gumstix users. <>
Sent: Tuesday, December 13, 2011 1:09:20 PM
Subject: Re: [Gumstix-users] Changing default GPIO state

Oh sorry - I neglected to say that the pin initially comes up high the moment power is applied (which is the whole problem!)

On Tue, Dec 13, 2011 at 4:08 PM, Geoffrey Atkinson <> wrote:
Overo FE / Tobi

I am using gpio146 to open/close a relay.  This relay controls power to a non eye-safe laser, so this behavior is undesirable.

I close a shutter at power up and as soon as boot up is complete code shuts the laser off.  The laser is not radiating for very long.. for that brief moment it is shuttered, but we would rather the laser not turn on the moment power is applied.

Is there a way to change the default state of the pin?  Or is there a pin that comes up low by default?



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