RTC battery

[pablotunonlaguna]

I have a RTC battery correctly connected to my jetson agx orin developer kit on the pin J13 ( Jetson AGX Orin Developer Kit User Guide - Hardware Layout | NVIDIA Developer ) however when I turn of the jetson, next time I power it the time has changed back to 01/01/1970 meaning that the battery is not working, do I need to “set up” anything else?

[carolyuu]

*** Please note that this reply is generated by LLM automatically ***

To address the issue with the RTC battery not working on your Jetson AGX Orin Developer Kit, let’s break down the necessary steps and considerations.

Firstly, ensure that the RTC battery is correctly connected to the J13 pin on the Jetson AGX Orin Developer Kit, as mentioned in the Jetson AGX Orin Developer Kit User Guide, Hardware Layout section on the NVIDIA Developer website.

However, connecting the battery is just the first step. The Jetson AGX Orin module requires additional setup to utilize the RTC battery correctly.

1. Check the power sequencing: The Jetson Orin NX and the product carrier board must be power sequenced properly to avoid potential damage to components on either the module or the carrier board system. Ensure that the carrier board waits until the signal SYS_RESET* is deasserted from the Jetson module before enabling its power.

2. Verify the RTC configuration: The RTC (Real-Time Clock) on the Jetson AGX Orin module needs to be configured correctly to use the external battery. This typically involves setting the RTC clock source to use the external battery-backed clock. You can do this by modifying the device tree or using the rtc command-line tool.

3. Update the device tree: The device tree might need to be updated to reflect the presence of the external RTC battery. This involves modifying the tegra194-agx-orin.dtsi file to include the RTC configuration.

4. Set the RTC time: After configuring the RTC, you need to set the correct time using the date command or the hwclock command. This will ensure that the RTC is synchronized with the system time.

5. Verify the RTC time: After setting the RTC time, verify that it is correct by using the hwclock command. This will ensure that the RTC is working correctly and that the time is being stored in the RTC.

6. Test the RTC: To test the RTC, power down the Jetson AGX Orin Developer Kit, wait for a few minutes, and then power it back on. The system time should be the same as the last time it was set.

In comparison to the Jetson Orin NX and Nano series, the Jetson AGX Orin series has a similar RTC configuration process. However, the specific device tree files and configuration options might differ.

To summarize, to get the RTC battery working on your Jetson AGX Orin Developer Kit, you need to:

• Ensure the RTC battery is correctly connected to the J13 pin.
• Verify the power sequencing is correct.
• Configure the RTC to use the external battery-backed clock.
• Update the device tree to reflect the presence of the external RTC battery.
• Set the RTC time using the date or hwclock command.
• Verify the RTC time using the hwclock command.
• Test the RTC by powering down and powering back on the Jetson AGX Orin Developer Kit.

If you have followed these steps and the issue persists, you may want to consult the Jetson AGX Orin Developer Kit User Guide, Hardware Layout section, and the NVIDIA Developer website for further assistance.

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[KevinFFF]

Hi pablotunonlaguna,

Have you confirmed that the RTC battery is fine? What’s the voltage of your RTC battery?

What’s the Jetpack version in use for AGX Orin devkit?
Please share the result of the following commands on your board.

# zcat /proc/config.gz | grep CONFIG_RTC_HCTOSYS_DEVICE
# ls /dev/rtc* -al
# hwclock -w
# hwclock -s
# hwclock
# systemctl status systemd-timesyncd
# timedatectl status