Zigbee Journey (9): Several important basic CC2430 experiments - systematic sleep and interrupted wakefulness

In this article, we will discuss the sleep function and wake-up method of CC2430. In actual use, the CC2430 node is generally powered by batteries, so the control of its power consumption is crucial.

As you can see from the table above, the CC2430 has a total of 4 power modes:PM0(fully awake),PM1(a little drowsy),PM2(half awake and half asleep),PM3(Sleeping very hard). The further back, the more functions are turned off, and the power consumption is lower and lower. The conversion relationship between them is as follows:

putPM1、PM2Wake upPM0, there are three ways: reset, external interruption, sleep timer interruption; But putPM3Wake upPM0, there are only two ways: reset, external interrupt (this is because inPM3All oscillators stopped working, and of course the sleep timer was turned off~)

Let's go through a small experiment to introduce how to enter sleep mode and how to wake upPM0state.

[url=] [/url]
/*
    Experimental description: Interrupted wake-up sleep experiment, which introduces wakefulness in three sleep modes
*/

#include
#define LED_ON  0
#define LED_OFF 1#defineled1 P1_0         
#defineled2 P1_1         
#defineled3 P1_2         
#defineled4 P1_3   [url=] [/url]

How to use a sleep timer to wake up the system can be summarized as follows:Open Sleep Timer Interrupt → Set the Sleep Timer's Timing Interval → Set the Power Mode

(Note: "Set the Sleep Timer Interval" step must be before "Set Power Mode", because the system will not continue to execute the program after entering sleep)

Next, let's focus on the subfunction that sets the sleep timer interval:setSleepTimer

First of all, a brief introduction to the sleep timer: it runs on32.768kHzof24th placeTimer, when the system is runningIn addition to PM3In all power modes, the sleep timer will beUninterrupted operation。

The registers used by sleep timers are:ST0，ST1，ST2。 The following is a detailed introduction to its functions from the CC2430 Chinese manual:

It can be seen that their functions include two aspects:Read，write。

　　Read: Used to read the count value of the current timer, the order in which the readings must be followed:Read ST0 → Read ST1 → Read ST2

　　write: Used to set the timer's comparison value (when the timer's count value = comparison value, an interrupt occurs), the writing order must follow:Write ST2 → write ST1 → write ST0

OK, let's explain it in combination with the source code:

(1) First, define an unsigned long variable (32-bit) sleepTimer to receive the current count value of the sleep timer:

(2) Then add the required time interval:

Here's a little explanation:

Why does 1s represent 32768? Because the timer is working below 32.768kHz, it takes 1/32768 s for every 1 added to the timer; Add 32768, and you will need 1s;

(3) Finally, the value of sleepTimer is used as the comparison value of the timer:

In this way, you can successfully set the timing period of the timer~

(Note: As for the other parts of the source code, I believe that combined with detailed annotations, you can easily understand, and I will not repeat it here)

Oh~ After taking 2 days of spare time, I finally got this log. I really found that writing a blog, especially a "reader-friendly" blog post, is indeed a physical job: rigor, aesthetics, logic... It's all about consideration.

Each time I post the code, I think it's too long, but I'm reluctant to use the folding tool that comes with the blog garden. Therefore, in this blog post, the author tentatively added some JQuery elements to achieve smooth folding of the code, and there is still a small sense of accomplishment, hehe (JQuery rookie, don't laugh at the master~). But I don't know if this really enhances the readability of the article, and readers and friends are welcome to comment:)

This month, the author really decided to take root in the blog garden, so I spent a lot of spare time writing blog posts. When I wrote a blog for the first time, although there were few comments, most of the logs had a click-through rate of more than 500, which was a small encouragement to me! It does take courage to publish content about microcontrollers in the blog garden, but I will stick to it~

The nine blog posts from the beginning to the present focus on the use of basic hardware modules on the CC2430 chip. So far, we have basically gone through most of the peripherals on the CC2430, but there are still things such as Flash access, random number generator, AES coprocessor, RF communication, etc., which have not been touched upon. However, the Zigbee journey is not over, and the author intends to selectively fill in these omissions in the next topic (implementation of the Z-Stack protocol).

In the next blog post, I plan to end Zigbee's first trip with a slightly more comprehensive and extended experiment - "temperature monitoring system", and explain how to comprehensively apply the knowledge points learned earlier.

In fact, it is not qualified to be called "ExplanationAs a beginner, the author only hopes to encourage each other and make progress together in the process of writing a doctorate!