I'm using to systemd to launch my application and on starting the application the GPIO07 is configured as Output and set to High I want to set it to low as the system startup.
2 Answers
If you want to ensure the GPIO is low you need to connect a resistor of about 4k7 ohms between the GPIO and a ground pin.
The GPIO will then stay low until it is configured to be an output.
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is there a way to change the default configuration to set it to low on start up ? Commented Oct 10, 2022 at 15:23
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There are several ways. Look at the documentation for config.txt. All software methods will suffer from glitches.– joanCommented Oct 10, 2022 at 15:25
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@joan: A point of clarification, please: Are you including directives in
/boot/config.txtas software methods?– SeamusCommented Oct 11, 2022 at 7:04
On boot ALL GPIO are configured as INPUTS. A few have pull up so may appear as HIGH. Others have pull down.
The easiest solution is to pick a GPIO which is configured to be what you want. The most reliable is to use a resistor to pull LOW.
It is possible to set GPIO state in config.txt but this will have a short delay.
All of the above is documented (and answered many times).
answered Oct 10, 2022 at 21:23
