ZigBee TI ZStack CC2530 5.3 Instance (ii) Terminal equipment low power consumption and battery life 01-theory

(Supporting source code , software , development boards and other resources, can be the blog of the same name QQ group: Napoleon 940911)

This section and the next section will tell about the low power consumption of ZigBee terminal equipment.

This section focuses on the low-power theory portion of ZigBee technology based on the CC2530 chip.

First, the application of the background

" Power consumption " is a very important issue in the areas of smart home, healthcare, or industrial control. Because in many practical cases, the device can only use battery power, and can not use 220V AC or 24V DC power and so on to keep the device constant power. At this point, low-power technologies are especially important. Otherwise, frequent battery replacement will cause great waste to human and material resources.

and " Low power " is one of the many important features and advantages of ZigBee technology, so ZigBee technology in many areas have a very wide range of applications.

Second, the basic concept of ZigBee review

When it comes to the low power consumption of ZigBee technology, here we have to reiterate some basic concepts of ZigBee. There are three logical devices in the ZigBee Network: Coordinator (Coordinator), Router (Router), and Terminal (Enddevice).

Coordinator Node : is the first device in a network. Responsible for creating, maintaining and managing the network, etc., must be powered by the main power supply.

Router Node : mainly responsible for routing discovery, message transmission, allowing other devices to join the network through it, etc., generally also use the main power supply often.

End Node : generally responsible for data acquisition or control functions, only through the coordinator or router to join the network, and other devices can not join the network through it. Because it does not have the responsibility of maintaining the network structure, it can sleep or wake up, consumes less power, and generally uses battery power.

Thus, the real low power consumption in ZigBee technology is only for the terminal equipment . For the normally powered ZigBee coordinators and ZigBee routers, we generally do not consider their power consumption.

PS: "Equipment" mentioned later in this article, non-special instructions, refers to "ZigBee terminal equipment".

Three, dynamic power consumption and static power consumption

For ZigBee terminal equipment, sometimes it is "something to do", but more often it is "nothing to do". Here, we put ZigBee terminal equipment in "something to Do" and "nothing to do" two different situations of power consumption, respectively, called " Dynamic Power" and " static power consumption ." In this way, the power consumption of ZigBee terminal equipment is mainly composed of " dynamic Power" and " static power consumption " two parts.

Here we will use a diagram in the following section to briefly explain:

Above is a ZigBee terminal equipment in the network and the network after the real-time power consumption diagram, you can see as shown in the intersection of the current at the size of 8.087mA.

From the figure can see a lot of " Burr ", in fact, at this time, ZigBee terminal equipment is interacting with its parent node, or is collecting sensing data, etc., this time the power consumption is what we call " dynamic power "; more often, even 90. % of the time, it is actually "nothing to do", which is shown in the figure " Smooth zone ", this time the power consumption is what we call " static power ."

This shows that the actual dominant position is actually " static power consumption ".

Four, CC2530 sleep mode

As described in the manual "Cc253x User's Guide" 4.1 Power Management Introduction:

There are 5 modes of operation in CC2530, 3 of which are sleep modes, PM1, PM2, and PM3, respectively.

In addition, the manual mentions that although CC2530 has three different sleep modes, only two of the Z-stack protocol stacks are used.

The code in the protocol stack is exactly the same, using only PM2 and PM3, respectively, called Timer_sleep (timed sleep) mode and deep_sleep (deep sleep) mode .

The documentation also has the following instructions:

Since deep_sleep (deep sleep) mode must be " reset" or " external interrupt " to wake up, it is generally only suitable for devices that require a key type. If an external interrupt cannot be generated, the PM2 mode is generally used, i.e. timer_sleep(timed sleep) mode .

(Supporting source code , software , development boards and other resources, can be the blog of the same name QQ group: Napoleon 940911)