A method and system for realizing countdown by wireless low-power device

Abstract

The present application discloses a countdown method for a wireless low-power device, including: setting the initial timing time of the first timing system; setting the timing cycle; obtaining the n-1th timing cycle in the first timing system The remaining time of the countdown at the end; the time difference between the two timings at the end of the n-1th cycle and the end of the nth cycle in the second timing system; when n=0, the countdown of the first timing system The remaining time is the initial time of the countdown; when n>0, the remaining time of the countdown of the first timing system is obtained according to the following formula: Tn=T n‑1 ‑(t1‑t2), compared with the prior art, this application has the following beneficial effects: the low power consumption device realizes the local countdown function, and the cumulative countdown error caused by task blocking can be corrected by the system clock calibration method to achieve low The countdown error of the power consumption device is within the acceptable range.

Description

technical field [0001] The present application relates to the field of smart home, and in particular, to a method for counting down a wireless low-power device. Background technique [0002] In the prior art, low-power devices need to enter a sleep mode due to battery power supply for power saving requirements, but in the sleep mode, some basic functions need to be maintained to be able to respond quickly. Therefore, it is necessary to set the wake-up source. Before the task-driven device enters the sleep state, it will judge how long the next task needs to be performed. After entering the sleep mode, it relies on the sleep RTC to calculate when to wake up to execute the latest task. However, when the two tasks are close in time and there is no preemption mechanism, the task that should be running will be blocked by the executing task. Therefore, if the periodically running task requires high time accuracy, there will be errors over time. ever-expanding problem. [0003] S...

AI Technical Summary

Problems solved by technology

[0007] But task B itself also has execution time and there is no task preemption mechanism

For example, if the countdown task B is executed for 300ms, it will cause the countdown task A to be executed after 1100ms, which will cause a time error of 100ms.

[0008] Subsequent tasks blocked before the countdown task A will also cause the execution time error of the countdown task A to increase, making the cycle of the countdown task A longer

The above-mentioned problems in the countdown function will lead to continuous time error accumulation. Assuming that there will be an error of 100ms each time, after running ten times, there will be a countdown error of 1 second.

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