Enable 1PPS as an Output on Jetson-GPIO Pin Header

Hi All.
I would like to be able to control an GPIO Output pin on one of the header pins of a Jetson AGX Orin Dev-kit.

A 1PPS signal will arrive as an input to another pin and be bound to the kernel PPS consumer by a “ppsctl” function and sync the internal system clock this way.

(See for ex. linux - PPS: how to adjust system clock from PPS? - Stack Overflow)

May an output pin be latched the same way? I have not found any detailed info on how to do that.

It may be needed to forward the 1PPS signal like this.

Any help will be much appreciated.

BR, Atle

Hi atle.storteig,

What’s the Jetpack version in use for AGX Orin devkit?

Sorry that I’m not clear about your requirement.
Do you want to control a GPIO(Output) as PPS source and connect it to another pin(Input) as PPS input?
Please let us know the exact pin you want to use and the block diagram of your connection.

Hi Kevin - thank for the answer, I find no traces of Jetpack from the suggestions at Google and GitHub - do you have any commands for me to send?

How does JetPack relate to GPIO/1PPS, sorry I do not understand ?

The nVidia itself has no accurate clock itself.
So, the 1PPS is provided from another system (separate module/chip made to be a stable XO), then shall enter a GPIO input-pin at the nVidia for it to sync the internal clock nVidia board.

Secondly, a GPIO output-pin will be used to forward sync to the next controller in the chain - if possible from the kernel functions.

The pin used will be any appropriate output-pin from the pin-mux.

Sorry if I was not clear about this.

thanks again.
BR, Atle

Please just share the result of the following command on your board.

$ cat /etc/nv_tegra_release

Okay, we can start from this.
Please refer to the following topics for the users have enabled PPS on their case.
Enable PPS on Jetson Linux 35.3.1 for Xavier AGX - Jetson & Embedded Systems / Jetson AGX Xavier - NVIDIA Developer Forums
Pps_gpio interrupt not asserted - Jetson & Embedded Systems / Jetson Orin NX - NVIDIA Developer Forums
Custom Device Tree Overlay - Pin Mapping - Jetson & Embedded Systems / Jetson Orin NX - NVIDIA Developer Forums

Hi Kevin, thanks for your answer.

Sorry that command is not valid here, this is a custom-built Linux-distro from Yocto.

This is the Jetson AGX Orin Dev Kit. I will be happy to run any other commands from you.

Do you by any chance know what voltage levels the GPIO need for an 1PPS interrupt?

BR, Atle

Anecdotally, my GPS unit produces a PPS signal with a 3.3V logic level. From what I recall the GPIOs are 3.3V tolerant on Jetson Dev Kits, if you’re using a different carrier that might be different.

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@roo, thanks a lot - most appreciated!
BR, Atle

Sorry that we don’t support for yocto project, but I think there may be similar configurations/drivers to enable PPS.

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