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My Pi Zero is powered by a small ATX PC power supply that is also powering a few other components: projector, audio amplifier. I'm using the gpio-shutdown device tree overlay to add a power button on the BCM pin 3 interrupt.

This works great, except that the Pi initiates the boot sequence when the PC power supply is turned on. This is not what I want; I want the boot sequence to start only after power is applied AND the power button attached to BCM 3 is pressed.

Is there a way to accomplish this - to start the Pi when the power button attached to BCM 3 is pressed?

Seamus
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RyanScottLewis
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1 Answers1

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IBM computers have circuitry to hold the processor in HALT state until voltage is stable.

You could do similar on the Pi by pulling the RUN header low. This will require additional circuitry, but as we don't know what you are using this is up to you.

PS ATX power supplies are a poor choice for the Pi. They are designed to supply large currents, and perform poorly if lightly loaded!

Milliways
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