30 lines
821 B
Markdown
30 lines
821 B
Markdown
Testing system time using 32k clock
|
|
=====================================
|
|
|
|
If 32k crystal is correctly configured, then system time (as measured against realworld time measured by stop watch)
|
|
should match onboard RTC time. It is a good idea to disable networking to prevent NTP from adjusting time behind our back.
|
|
|
|
you need a stop watch, and linux shell prompt on board:
|
|
|
|
```
|
|
cd /sys/class/rtc/rtc1
|
|
cat time;sleep 120;cat time
|
|
```
|
|
|
|
Start stop watch at the time of pressing enter - it should print time = 120 seconds (+1 second to account for milliseconds).
|
|
|
|
```
|
|
debian@BeagleBone:/sys/class/rtc/rtc1$ cat time;sleep 120;cat time
|
|
06:40:32
|
|
06:42:32
|
|
```
|
|
|
|
Test onboard RTC as well (to ensure 32k crystal for that rtc is working)
|
|
|
|
```
|
|
debian@BeagleBone:/sys/class/rtc/rtc0$ cat time;sleep 120;cat time
|
|
06:47:02
|
|
06:49:02
|
|
|
|
```
|