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RTC

Usage Instructions​

  • Install the battery

    • As shown in the image, install the RTC battery onto the Raspberry Pi Compute Module 4 IO Board.

      RTC

  • Power on to start

  • Check the device

    • RTC is typically mapped to a device file in Linux. You can check the /dev/rtc* or /sys/class/rtc/ directory to verify if the RTC device has been recognized and loaded.

  • Read the current RTC time

    • Use the hwclock command to read the current RTC time. Execute the following command in the terminal:

      sudo hwclock -r

  • Write the time

    • If you need to set the RTC time, you can use the hwclock command and provide a new time value with the --set option. For example, to set it to the current system time, use:

      sudo hwclock --set --date="2024-07-09 15:43:15"

  • Continuous testing

    • Disconnect the Raspberry Pi Compute Module 4 IO Board's network connection and power, and after ten minutes or longer, read the RTC time again. The time should be based on the previously set time, with the elapsed time added.