Difference between revisions of "Using the real-time clock"
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Joost.Weijs (talk | contribs) (Created page with "The Open.OC 2 carrier board contains a realtime clock (RTC) with battery backup: the PCF8563. The custom kernel+DT automatically integrates the clock functionality into the OS...") |
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The Open.OC 2 carrier board contains a realtime clock (RTC) with battery backup: the PCF8563. | The Open.OC 2 carrier board contains a realtime clock (RTC) with battery backup: the PCF8563. | ||
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| − | ... | + | == Test == |
| + | |||
| + | * Check: <code>dmesg | grep rtc-pcf8563</code>. It should show: | ||
| + | : <syntaxhighlight lang="bash">rtc-pcf8563 1-0051: rtc core: registered rtc-pcf8563 as rtc1</syntaxhighlight> | ||
| + | : An extra error message about low voltage can show up when the rtc is not configured. | ||
| + | : rtc is accessible in /dev/rtc1 | ||
| + | |||
| + | * In Linux, <code>date</code> should show the current date. If it needs to be set, use: <code>sudo date --set "2021-07-27 9:34:00".</code> | ||
| + | |||
| + | * To write the current time to the rtc: <code>sudo hwclock -w -f /dev/rtc1</code> | ||
| + | |||
| + | * To read the current time from the rtc: <code>sudo hwclock -r -f /dev/rtc1</code> | ||
Latest revision as of 11:33, 27 October 2021
The Open.OC 2 carrier board contains a realtime clock (RTC) with battery backup: the PCF8563.
Test
- Check:
dmesg | grep rtc-pcf8563. It should show:
rtc-pcf8563 1-0051: rtc core: registered rtc-pcf8563 as rtc1
- An extra error message about low voltage can show up when the rtc is not configured.
- rtc is accessible in /dev/rtc1
- In Linux,
dateshould show the current date. If it needs to be set, use:sudo date --set "2021-07-27 9:34:00".
- To write the current time to the rtc:
sudo hwclock -w -f /dev/rtc1
- To read the current time from the rtc:
sudo hwclock -r -f /dev/rtc1