Overview of WeChat's method for implementing LED lighting intelligent control

With the development of the Internet and the advent of the 3G era, cloud computing and cloud networks have emerged. Big data videos can be directly downloaded to smart phones for online viewing without any stagnation. In this environment, smart home technology is also undergoing earth-shaking changes. At present, the smart control products of well-known brands are still mainly wired, such as Schneider 's C-BUS[1], ABB's I-BUS, Honeywell's H-BUS, Emer's M-BUS, and Legrand TCL's SCS-BUS, which are basically all fieldbus technologies. With the increasing maturity of civil radio frequency wireless communication technologies, such as WiFi and ZigBee[2], they have obvious advantages over wired technologies, such as easy installation and disassembly, simple network structure, and low cost. These advantages, coupled with the speed of cloud networks and the transmission of big data storage, will set off a vigorous wireless smart control revolution in the fields of lighting, home appliances, security, etc.

　　Since the official launch of Tencent WeChat public platform on August 23, 2012, the number of users has exceeded 300 million, and the penetration rate in cities is extremely high. Almost everyone is using WeChat. WeChat's new functions are especially popular among contemporary young people. Convenient voice message sending and receiving consumes very little data, which is more economical and cooler than phone calls. There is no need to activate the GPRS function for sending and receiving pictures, and there is no need to worry about the pictures being too large to send. Everything can be done easily in a snap.

　　The technology described in this article is an intelligent control technology grafted onto the WeChat public platform and its cloud network, hereinafter referred to as WeChat Intelligent Control. WeChat Intelligent Control technology is powerful and covers a wide range of applications, and can be applied to most intelligent control occasions. This article takes smart home as an example to elaborate on its basic principles and powerful functions.

　　The basic application of WeChat smart control in smart home is shown in Figure 1. When the user sends text, voice, and picture information to the application end through WeChat on the mobile phone or computer, the information will be quickly transmitted to the router near the application end through the 3G network. Through the network cable TCP/IP protocol, the router then transmits the information to the WeChat smart control gateway (a gateway specifically used for WeChat smart control communication). The gateway stores data while performing protocol conversion and quickly converts the information into new instructions [3]. The new instructions have different forms and transmission methods in smart lighting, smart home appliances, and smart security applications. They are discussed below.

　　1. WeChat Intelligent Control - Smart Lighting

　　1. Introduction to ZigBee protocol

　　Every family needs to use lamps for lighting, but at present, the method of controlling lamps in China is still mainly ordinary switches, with a few using infrared remote control, 315MHz and 433MHz radio frequency remote control, etc. The WeChat intelligent control system uses the 2.4GHz ZigBee protocol [4], and ZigBee uses the on-demand routing AODV algorithm, which can easily realize intelligent networking and intelligent routing between lamps, and long-distance wireless information transmission. As shown in Figure 2(a), when the ZigBee remote control switch (node ​​1) issues a command to the table lamp at node 12, according to the AODV algorithm, the command will be transmitted to node 3, then node 7, node 10, and finally to the table lamp. The table lamp performs corresponding actions according to the command, such as turning on, off, dimming, timing, etc. When nodes 2 and 7 are removed from the network, as shown in Figure 2(b), when the command issued by node 1 switch is sent, the route will be recalculated. The new route will pass through nodes 3, node 6, node 11, and finally reach the table lamp at node 12. It can be seen from this that as long as every two nodes can maintain communication, the increase or decrease of nodes will not affect the communication.

　　2. Principle of smart lighting

　　(1) Remote control method

　　When you are thousands of miles away from home and want to control the lighting of your home lamps using WeChat on your mobile phone, you only need to tap the keyboard to enter text, or directly speak and record, and the command can be sent to your home router through the Internet. The router then transmits the command to the WeChat smart control gateway through the network cable. As shown in Figure 3, the WeChat smart control gateway packages the command according to the ZigBee protocol and radiates it outward through the ZigBee antenna. The application-side ZigBee wireless transceiver module [5] is built into the lamp, and two adjacent lamps can communicate with each other. A large number of lamps can form a lighting network. The network will find the optimal transmission route using the on-demand routing algorithm AODV and finally send the command to the target lamp. The target lamp will immediately respond to the command, such as turning on, off, dimming, timing, or returning the current working status.

　　(2) Remote control method

　　The smart lighting system of WeChat smart control not only supports long-distance control of lamps, but is also fully compatible with short-distance remote control. As can be seen from Figure 3, there are four main control terminals for short-distance remote control: WeChat smart control host, computer, mobile phone and remote control. Their control methods are as follows: The first control method. It is mainly designed for WeChat smart control host, computer and mobile phone. These three machines are installed with corresponding APP application software, which can directly turn on, off, dim and delay each lamp in the home. These three machines are interconnected with the router through WiFi. The instructions they send to the router are transmitted to the WeChat smart control gateway through the network cable. The gateway then transmits the instructions to the target lamp through the ZigBee antenna and the lighting network. The lamp makes corresponding actions according to the requirements and can send back the working status at that time. It can be seen that in this control method, when the instruction reaches the router, it is basically the same as the remote control method. The second control method is the remote control method. Each lamp has a corresponding position button on the remote control, while function keys such as dimming and delay are shared. To illustrate, if you turn on a desk lamp and adjust it to 50% brightness, you first press the button on the remote control that corresponds to the desk lamp. This indicates that the following function settings are for the desk lamp and have nothing to do with other lamps. When the desk lamp receives a "roll call" command, it will reverse its current state. That is, if the desk lamp was originally on, it will now be turned off; if the desk lamp was originally off, it will now be lit. After the desk lamp is lit, use your finger to directly click on the 50% position of the continuous dimming ring. This method is the simplest and can easily control lamps without the need for routers, gateways and other equipment. 　　2. Smart home appliances controlled by WeChat

　　1. Remote control method

　　The remote control method is similar to that of smart lighting. When you use WeChat to send commands to control home appliances such as air conditioners, color TVs, and rice cookers on your mobile phone or computer, the commands will be quickly transmitted to the router at home through the Internet, and the router will then transmit the commands to the WeChat smart control gateway through the TCP/IP protocol. As shown in Figure 4, the WeChat smart control gateway repackages the commands and irradiates them through infrared LEDs . The infrared rays will be reflected by the wall, and the signal will eventually reach the target appliance. The target appliance will take corresponding actions according to the command requirements, and the communication ends.

　　However, the situation of controlling the rice cooker here is a bit special, because most rice cookers currently do not have remote control function, so a ZigBee relay switch is connected in series at the power supply of the rice cooker. In this way, when the WeChat intelligent control gateway receives the command to control the rice cooker, it will use ZigBee communication to send the command to the wireless relay switch, which will turn on or off the power supply to the rice cooker according to the command.

　　2. Remote control method

　　As shown in Figure 4, there are also four control terminals in smart home appliances, which are similar to smart lighting. When the WeChat smart control host, computer and mobile phone are controlled, they use the wireless network, passing through the router and WeChat smart control gateway, and finally the WeChat smart control gateway infrared remote control home appliances to complete the corresponding actions, but omitting the LAN and cloud network communication part. The specific principle is mentioned above.

　　The use of remote controls to control home appliances is quite common and familiar to everyone, so I will not go into details here.

　　3. WeChat Intelligent Control: Smart Security

　　How can you know what is going on at home when you are away on a business trip? How can you sing a song for your family member's birthday? If there is a burglary, gas leak, or intrusion at home, how would you know? And what should you do? The answers are in the following chapters.

　　1. Remote control method

　　(1) Understand the family situation

　　When you are on a business trip in another city, you can open your mobile phone and log in to WeChat, and ask your friend's "home" for surveillance video. This information is first transmitted to the nearby communication base station, and then to the communication satellite in the sky. The communication satellite then transmits the information to the nearest communication base station to your home, and then the base station transmits the information to your home router via Ethernet. As shown in Figure 5, the router sends the information to the WeChat smart control gateway via the network cable. The gateway immediately reads the last video of the surveillance video in the disk array storage and transmits the video to the router. The router then transmits the video to your mobile phone WeChat via Ethernet. After seeing this video, you will have a general understanding of the situation at home.

　　(2) Send birthday wishes songs

　　If you want to sing a song for your family member on his/her birthday, you can do it as usual in a WeChat voice chat, press and hold the record button to start singing, release your hand after drinking, and click send. After the WeChat smart control gateway receives your voice message, it will play it through the home speakers. When your family hears the song you sing while away from home, they will definitely be very moved at this moment.

　　(3) Alarm system

　　Once there is a theft, gas leak, or intrusion at home, the corresponding vibration sensor, smoke alarm, gas leak alarm, and infrared detector will send an alarm signal to the WeChat smart control gateway using the ZigBee protocol. The latter will send the alarm signal and the current surveillance video to your mobile phone through the router and Ethernet, triggering the mobile phone alarm event, and at the same time send instructions to the wireless sound and light alarm to order it to start working to warn on the spot. You can also issue a warning on WeChat and let the speakers at home play your warning. You can also call relatives or friends to come to your home, or call the police at the place where the incident occurred.

　　When the smoke alarm is triggered, the sluice gate will be opened to start spraying water to extinguish the fire. When the gas leak alarm is triggered, the exhaust fan will be turned on to exhaust the gas. The system is intelligent, complete, easy to use, fast, low-cost, safe and reliable, and can minimize losses.

　　2. Remote control method

　　Similarly, security equipment can also be controlled at home. Commonly used control terminals include WeChat smart control host, computer and mobile phone. They all use WiFi protocol to communicate with the router. The router, WeChat smart control gateway and disk array storage are connected by network cable, as shown in Figure 5. The surveillance video is recorded at all times and the data is transmitted to the WeChat smart control gateway via WiFi. The latter stores the video in the disk array storage. If necessary, the control terminal reads the last video or picture and transmits it.

　　The alarms at home are divided into three categories according to the needs of theft, fire and intrusion: vibration sensors, smoke alarms and infrared detectors. As long as the triggering conditions exist, these three types of alarms will continuously send alarm signals to the WeChat Intelligent Control Gateway, which will transmit the alarm signals to the router, and the router will send the alarm signals to the control end. The WeChat Intelligent Control Gateway also sends signals to the sound and light alarm to command it to work. If the triggering conditions of all three types of alarms are cleared, the WeChat Intelligent Control Gateway will command the sound and light alarm to "sleep" and return to normal. Of course, you can also send a "shut up" command through the control end to stop the sound and light alarm from alarming; or disconnect the power supply of the sound and light alarm to stop it from working.

　　IV. Conclusion

　　The WeChat intelligent control system integrates smart lighting, smart home appliances and smart security. It uses WeChat's existing network and cloud services. It has the advantages of simple networking, low cost and maintenance cost, simple operation, complete functions, perfect system, safety and reliability. It is one of the most suitable smart home systems for ordinary families.