HOW to Increase GNNS timing module on Xavier?

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
9

Hi chengjingbo,

You can use GPIO as PPS interface.

Here are the steps:

  1. Enable CONFIG_PPS and CONFIG_PPS_CLIENT_GPIO configs in kernel
  2. Add Device tree node in kernel dtb anywhere inside dtb like following:
    pps {
    gpios = <&tegra_aon_gpio TEGRA194_AON_GPIO(AA, 0) GPIO_ACTIVE_LOW>;
    compatible = “pps-gpio”;
    assert-falling-edge;
    status = “okay”;
    };
    You can choose any GPIO present on 40-pin (J30) for this purpose.
    Compile, update dtb and flash system with above changes.

After system boots, you will see sysfs node for PPS.
$ ls /sys/class/pps/pps0/
Whenever interrupt occurs on falling edge of signal, timestamp will be captured and seen using:
cat /sys/class/pps/pps0/assert

If you want events to generate on rising edge of signal then remove assert-falling-edge; property from device node.
Let me know if you need any help.

Thanks,
Shubhi Garg