You may use parts from TXC, https://www.txccrystal.com/crystal.html
Size is probably your only consideration and our reference is a 3.2x.2.5x0.7 mm, and also 20ppm.
RTC is turned off during HIDOFF, therefore system time is reset.
内部的24mhz ,RTC 的时间误差很大。所以需要外接高精度的32K晶振。另外一个问题,当HIDOFF 唤醒后,系统时间会丢失吗?
You may use parts from TXC, https://www.txccrystal.com/crystal.html
Size is probably your only consideration and our reference is a 3.2x.2.5x0.7 mm, and also 20ppm.
RTC is turned off during HIDOFF, therefore system time is reset.
好的,谢谢!
我进入 HIDOFF 的模式代码如下:
/* Enable low power mode operation */
wiced_sleep_config( WICED_TRUE, 0, 0 );
/* Initialize the power save mode by passing the wakeup sources as the input parameter */
wiced_allow_sleep(TRUE);
wiced_power_save_start(WICED_WAKE_SOURCE_ALL, 60000);
我这样设置的wake up 时间,也会关闭RTC ?我需要 deep sleep 模式下,唤醒后RTC 不会重置系统时间怎么配置?
这个算是timed wakeup sleep,不会关闭rtc。HIDOFF比这个更彻底,所以会把rtc也关掉。
那为什么唤醒后,起来后RTC 的时间会丢失?
In HIDOFF, both LPO and RTC will be turned off.
In Timed-Wake, LPO and RTC are still active.
This is the definition for the two low power mode. Therefore if you specify 60s in your function call, then it is technically
a time-wake event, and not a hidoff.
Thanks.
So Why dose the device wake up has a not right RTC time with Timed-wake Mode?
Please help me use which API can make the right RTC when device wake up.
I am using these code.
/* Enable low power mode operation */
wiced_sleep_config( WICED_TRUE, 0, 0 );
/* Initialize the power save mode by passing the wakeup sources as the input parameter */
wiced_allow_sleep(TRUE);
wiced_power_save_start(WICED_WAKE_SOURCE_ALL, 60000);
Please refer to the following thread: cyw20706 怎么同步系统时间
I have attached a project for the RTC in the timed wakeup mode. You need to do some configuration when the system wakes up.