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General discussion • GPIO output voltage at startup

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Setup Details + Intent:
My PI, in the current setup, controls a few peripherals depending on whether GPIO14 is a 1(3.3V) or a 0(0V).
What I hope to do is for PI to boot-up, and automatically run a python script (let's call it sense.py) to continually sense environment, and set GPIO14 depending on sensed value.

Experiment:
I connected a multimeter to GPIO14 to check the voltage that appears on this pin as PI boots. As PI boots, I see voltage readings as follows on GPIO14:
(a) first 3-4 seconds 3.29V, and
(b) once PI boots -- I can see login screen -- 0.7 to 0.8V

Question + concerns:
How do I avoid (a)? I don't want things to turn on during PI boot up process.
(b) is not such much of an issue. Once PI boots, I can set GPIO initial voltage to zero or one during the GPIO.setup() and later drive 1 or a 0

Statistics: Posted by microberry — Tue Sep 03, 2024 12:13 am



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