Enable PPS on Nvidia Jetson Orin Nano 8GB (SD) Devkit NVME

Product support
1

Hello, I am trying to connect a GPS to the Nvidia Jetson Orin Nano 8GB (SD) Devkit NVME, to enable the PPS functionality.
Is there any documentation on configuring the Balena OS to allow it to?
For example, I see that in other devices we can enable it with the dtOverlay

dtoverlay: "pps-gpio,gpiopin=18"

Thanks in advance.

2

Hello @pgiotis good to see you here!

could you please share more details on how are you connecting the GPS?

what error do you get?

thanks

3

Hello Mpous,
Thanks for your reply.
I am not getting any error. I am just trying to find documentation on how to configure it like the dtoverlay that does not exist on Jetson.

The GPS is connected to 5.0v, GND, UART1_TX, UART1_RX and GPIO09

4

Thanks @pgiotis could you please share the balenaOS version that you are running?

In the other hand, I don’t think dtoverlay is available in NVIDIA Jetsons. However let me check with the team to confirm the next steps for you.

5

I am using balenaOS 6.4.0.
dtoverlay is not available in NVIDIA Jetsons.

6

@pgiotis could you please confirm what do you see running this?

dmesg | grep -i tty
ls /dev/ttyTHS*

Thanks!

7

Below you can see the results

root@balenauuid:~# chronyc sources
MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^- chronos.physics.uoc.gr        2  14    17   136   +515us[ +895us] +/-   71ms
^+ time.cloudflare.com           3  14    17   136  -5270us[-4890us] +/-   31ms
^- tara.castrovalva.org          2  14    17   137    -59us[ +321us] +/-   86ms
^* office.ipacct.com             1  14    17   136  +4474us[+4854us] +/-   13ms

root@balenauuid:~# dmesg | grep -i tty
[    0.000000] Kernel command line: mminit_loglevel=4 console=ttyTCU0,115200 firmware_class.path=/etc/firmware fbcon=map:0  video=efifb:off console=tty0  console=null quiet splash vt.global_cursor_default=0 consoleblank=0 l4tver=36.4.3 rootdelay=1 roottimeout=60  sdhci_tegra.en_boot_part_access=1 rootwait video=efifb:off root=LABEL=resin-rootB bl_prof_dataptr=2031616@0x271E10000 bl_prof_ro_ptr=65536@0x271E00000 
[    0.000374] printk: console [tty0] enabled
[    0.089890] 31d0000.serial: ttyAMA0 at MMIO 0x31d0000 (irq = 117, base_baud = 0) is a SBSA
[    0.200558] printk: console [ttyTCU0] enabled
[    2.382109] printk: console [tty0]: printing thread started
[    2.383319] printk: console [ttyTCU0]: printing thread started
[    2.418164] 3100000.serial: ttyTHS1 at MMIO 0x3100000 (irq = 112, base_baud = 0) is a TEGRA_UART
[    2.418718] 3140000.serial: ttyTHS2 at MMIO 0x3140000 (irq = 113, base_baud = 0) is a TEGRA_UART

root@balenauuid:~# ls /dev/ttyTHS*
/dev/ttyTHS1  /dev/ttyTHS2

Thanks

8

Hi, dtoverlay is not supported for Jetson Orins, but you can create your custom device-tree with that overlay applied and then configure the board to use it. For details, please see I2C and Other Interfaces | balena

1 Like
9

The PPS device is recognised.
The only thing that we need to play the PPS as a priority is to change
the chrony.conf.

So we login to the host and add the line below to /etc/chrony.conf

refclock SHM 0 refid NMEA offset 0.000 precision 1e-3 poll 0 filter 3
refclock PPS /dev/pps0 refid PPS lock NMEA offset 0.0 poll 3 trust

Thanks

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