I. Introduction of Internet of Things devices and Tencent

1. Device classification

The basic concept of the Internet of Things is the infrastructure that connects people to things and things to things, just like the Internet. Things are devices of the Internet of Things. When it comes to devices of the Internet of Things, you may think of the diagram of the rapid growth of devices of the Internet of Things, which is estimated to reach 10 billion yuan in 2020.

This shows that iot devices are growing exponentially and in a blowout way, which also shows that the prospect of iot is very broad.

The connected intelligence mentioned in the topic refers to smart devices, and the general direction is the Internet of Things devices combined with local or cloud AI capabilities. When participating in some forums, people will talk about AI and IoT together, abbreviated as AIoT. Today we’re going to start with basic equipment, which is also good for most listeners.

There are many dimensions to the classification of iot devices. The first dimension is the way the cloud is on the device. Because the Internet of things is the connection between devices and people, the connection must be done through the Internet, and how can the device go to the cloud?

There are basically two ways. First, the device is directly connected to communicate with the cloud. The other is that a sub-device connects to the cloud through a gateway. This is special for Bluetooth devices, which need to be connected to the cloud through bluetooth communication between mobile phones and Bluetooth gateways.

The connection mode between the gateway and sub-devices can be star-like, net-like, or tree-like. It applies to the connection between sub-devices and gateways in many scenarios.

The cloud connection is two-way notification. The cloud needs to control the device, and the device also needs to push messages to the cloud. This involves the basic protocol of the Internet of Things, MQTT protocol, which is actually a network architecture of the subscriber mode. Interested students can refer to the information to understand. On the mobile end, Websocket can also provide corresponding functions to achieve the same effect.

You can see that the gateway in the picture has both wireless signals and some serial ports are wired, which reflects another dimension of device division: communication mode. The broad categories of communications are simple: wired and wireless.

Cable equipment is a cable, through the home network port and USB connection, home has built a home video surveillance system, cable video surveillance system is connected to the central hard disk recorder through USB or network port. The second is serial communication, it is used more in the industrial field, the advantage is that it can be programmed through C++ and some other languages.

Wireless communication is divided into LOCAL area network (LAN) and wide area network (WAN). The devices closest to our life are classified as Wi-Fi devices, which communicate with the cloud through connecting the router at home, and Bluetooth devices, which can form a mesh network topology with devices to achieve communication between devices.

Another part of wireless communications in the area of wan, one is the carrier network, such as 3G, 4G, 5G. There is also a part of the wide area network singled out by the low power wide area network, this kind of equipment power is relatively low, there are two categories, one is NB-iot, the other is Lora. The NB-iot is a low-power network built on carrier networks. Currently, the popularity of nB-iot is relatively high. Each device has its own advantages and disadvantages, which will not be described here.

Some devices have two or three modes of communication, so the combination can play to the strengths and avoid the weaknesses. Take three examples. First, the combination of Wi-Fi and Bluetooth, because Wi-Fi has high power consumption and bluetooth has low power consumption, its connection is reliable and has strong anti-interference. The combination of wi-fi and Bluetooth can improve the success rate and convenience of wi-fi device network allocation.

The second is the combination of Bluetooth and 3G network. Take The 3G version of Apple Watch as an example. The third is the combination with NB-iot. Bluetooth can communicate and precisely locate objects within a short distance, and also take into account long-distance data transmission. Although there are not many categories of devices, they play their advantages in their own fields and their combination can be applied to many application scenarios.

2. Device life cycle

First of all, when developing an Internet of Things device, end-to-end security should be taken into account to ensure that data communication is secure when the device communicates with the cloud. Generally, certificate or key authentication is used, and debugging function improves the efficiency of development obviously.

The second step is how to connect the device after mass production. The connection involves Bluetooth or network configuration to connect the device to the cloud. Another dimension is that the device should be registered in the cloud.

The third step is the control of the device, which needs to be controlled by the cloud. In the field of devices with strong interaction with people, a powerful control panel at the C-terminal is also needed for precise control of certain attributes of the device, as well as the on-off and off-line processing of the device.

In another dimension, the linkage between devices is sometimes analyzed and controlled by the cloud. For example, when the temperature sensor in a home reaches 30 degrees or more, the air conditioner in the home needs to be turned on.

The fourth step is to monitor the health of the device, collect its logs, and analyze its data for business decisions and other purposes.

As the product is iterated, firmware needs to be updated. It is impossible for users to buy a new device after the product is updated. It is not a one-shot deal.

The last step is that the device is no longer used or offline, and the cloud needs to delete and clean up the data.

Although there are six steps, the connection, control and monitoring is the most active period of equipment, corresponding to the human life is like our middle age. Technically speaking, these three stages involve technical points and are relatively difficult.

3. Product Overview of Tencent Lianlian

In terms of products, Tencent Cloud IoT is committed to helping the vast number of Internet of Things developers to do a good job in the infrastructure construction of equipment life cycle management, to ensure the usability, integrity and high availability of functions, so that developers only need to focus on their own business logic, so as to seize the opportunity to release products in the shortest time.

The architecture diagram of the whole Iot product development platform is as follows:

As shown in the figure, developers can develop and debug the device on the Developer platform of the Internet of Things, and see the monitoring logs and data analysis of the device on the console. At the same time, Tencent also launched the C-terminal application Tencent Lianlian to help users do device management, including device connection, interaction, update, delete and so on, which can further shorten the c-terminal product development process of the manufacturer’s device mass production.

Why should Tencent do small program at the beginning? We also have some understanding of the small program, the advantage of the small program is easy to install, give a TWO-DIMENSIONAL code can be opened, unlike the installation of the APP is so tedious, it is strongly bound with wechat inside the chain.

The devices of the Internet of Things are also strongly bound to people. In both the home and enterprise fields, they need to interact with a group of people. Its advantage lies in this. For developers, small programs can use a grammar to run at both ends, do not need to deal with android, IOS side compatibility problems, can greatly reduce and shorten the development cycle, and can simplify the development of intelligent role a front-end can be done before to two end developers to do the work.

If based on users, Tencent lianlian is 2B, developers and users have some appeals must be to achieve. Tencent lianlian also went to interview and survey before doing, and found that the industry has a lot of concerns about the control and management of small programs, because it thinks that the underlying interface provided by wechat small programs is not strong enough and stable.

However, we still believe that there is no impossible thing, only the people who can not do things, so we can basically support the existing ability. Wechat also supports function construction and performance optimization in the field of IoT, so Tencent Lianlian started to do it, and the fact proves that we have also done it. In order to apply to more scenarios, such as foreign users or other scenarios, we also provide lianlian APP version and related SDK.

Ii. Tencent Lianlian’s ability and construction optimization in device connection

1. Configure a network for Wi-Fi devices

First of all, wi-fi devices need to go through 5 steps in the cloud, because Wi-Fi devices don’t know anything at first, they are bought at home, and they need to be told the password and SSID of the router at home. Therefore, the first step is that the mobile terminal needs to tell the device the SSID and password, and the device terminal can connect to the Wi-Fi of the router after knowing it.

The device and mobile phone are both in the LAN of the router. Through the LAN communication, the device terminal can inform the APP of the current device triplet information (basic device information). The device can directly register the device in the cloud, and the mobile terminal can bind the device to its own name in the cloud after successful registration.

The first step is to transmit the SSID and the password. To achieve this step, there are a lot of distribution schemes. We call it narrow distribution network. The second is the generalized distribution network. The generalized distribution network is the successful binding of devices so that devices can communicate with the cloud. This is the concept of the generalized distribution network.

The challenge to the connection of the small program side is mainly how the mobile phone can inform the device of the wi-fi information of the router in the narrow sense of network configuration, and the subsequent binding operation can be directly dialed to an interface.

Wi-fi has a very high application scenario and popularity rate for devices. In some environments with inconvenient wired connection and limited physical space, wi-fi devices can be easily used to access the cloud on devices. When you need to communicate with other devices, because the devices are all on the same LAN, you can communicate with them through TCP or UDC.

Wi-fi is suitable for scenarios with high compatibility. The compatibility has two dimensions. First, the device needs to be connected to any Wi-Fi in the world, which is guaranteed by the Wi-Fi Alliance, because Wi-Fi authentication is backward compatibility and specifies a unified global standard.

Another dimension is that any wi-fi enabled phone can be configured normally, so don’t worry about that. As far as we know, smartphones have been wi-fi capable since the iPhone 4, but of course they have problems and weaknesses, namely very high power consumption. It is based on 2.4g frequency band, the anti-interference ability is relatively weak, so the current market is gradually shrinking, of course, here is just to give you a general concept.

We can look at the narrow definition of Wi-Fi network, the device side to obtain SSID and password mainly divided into two aspects, on the one hand is the standard network configuration, on the other hand is the one-click network configuration.

Standard distribution network is a relatively high compatibility distribution network scheme, the current module manufacturers will generally support. One-click network configuration is a set of network configuration protocols with private protocols and security considerations provided by various manufacturers in order to improve user experience, including wechat AirKiss protocol.

At present, we have taken over the late maintenance of this agreement from wechat. Lexin ESPTouch smartConfI protocol, Realtek Simpleconfig protocol and so on, there are many other, we only list here Tencent lianlian now support network protocol as shown in the figure:

Low-power and Wi-Fi scenarios and dual-mode networking scenarios are also listed in the one-button networking dimension, which we also support.

With the foundation of narrow distribution network, the next step is to investigate whether wechat small program has such technical ability. At present, it is basically based on these three capabilities for development, one is the ability to connect to Wi-Fi, the other is the UDP communication ability, and the third is the bluetooth communication ability. Tencent lianlian also developed based on this technical ability.

The protocol of network configuration is briefly introduced: the device generates a hotspot, and the mobile phone joins the hotspot. After joining the hotspot, the applets can communicate with the device through UDP. The applets send Wi-Fi information and network configuration information to the device, and the device can connect to the router normally. At this time the small program also need to switch their network to the router. After the device has the ability to go to the cloud to register the device, of course, there must be some security considerations involved.

After a device is registered, the mobile phone polls the registration status of the device and binds the device. So why not tell the applet side the registration status of the device directly?

This is the beginning of the process, because the basic interface of the applets is connectWi-Fi, UDP communication has a failure rate, so if the device directly informs the applets of the registration status, there will be some failure rate.

UDP is connection-oriented and has a certain packet loss rate. As a result, it takes a long time for the applets to be informed of the registration status. According to this success rate and time considerations, we changed the process, by the small program end itself polling behind the state, is helpful to the success rate and time.

SoftAP displays the effect and posts logs on the device side. Logs on the device side are very important during Wi-Fi network development, which greatly saves development time and helps locate problems in the later stage. Currently, I am using SecureCRT for device side connection and log capture. I can also switch SoftAP with AT command, and the effect is very intuitive.

This whole process has four steps, which has some impact on user experience. The interface side of the small program needs to call Wi-Fi twice. However, because it is a protocol with strong compatibility, the current popularity is very high.

The basic principle of one-click network configuration is similar. First, the device needs to switch to promiscuous mode to capture all broadcast packet information forwarded by the nearby router. The mobile phone creates a UDP Client to send packets and a UDP Server to capture packets. After that, wi-fi information is broadcast, and the device can only parse the packet header because the device is not added to the router and has no key. After parsing the Wi-Fi information from the packet header, the device connects to the router.

At this time involves the small program side more special place, is the small program side no interface can get the IP of the local, so the device side is not directly to the small program side back package.

There are two ways to do this. After connecting to the router, the device continues to listen to the broadcast packets sent by the small program, because they are all in the same LAN, so you can get the source IP.

In another way, the device side broadcasts the packet back, and the small program side can also receive the packet back normally. After receiving the packet, the small program will verify the validity of the packet, register the device, poll the device status, and so on.

There are a few tricky points, starting with promiscuous mode, which accepts all 802.11 packets in the surrounding environment. On a message, because there is no in LAN communications, equipment side also did not join the router, received packet is encrypted, if you don’t get the router’s key is unable to unpack, so the Body part cannot resolve, explain only in baotou and packet length between the two information, wi-fi information can only be placed on the two.

Multicast addresses are reserved class D addresses that can be mapped to the destination MAC address. They are also fixed header + 23 bits of the IP address.

The packet information printed by the network adapter and the tool can be seen in the following table. The destination MAC address is the broadcast address above and the multicast address below. Can carry information and package size.

At present, Tencent lianlian small program support one-key distribution network protocol with the way of sending packets and carrying information, SmartConfig is multicast and broadcast support. But by putting information in the length of the packet, multicast broadcasting is only used to avoid the success rate of some 5G and 2.4g routers.

SimpleConfig uses multicast where the message is encoded in the target Mac address. Airkiss uses broadcast where the message is encoded in the packet length.

The last two columns, under my research, the industry only lianlian small program support these three ways of one-key network, this is the motivation we did this thing, can achieve differentiation here. Show the effect of one-click network configuration, you can see the most intuitive feeling of its interaction process is less than the previous step, only need to fill in the WI-FI router SSID and password to initiate a connection.

The two network modes are not mutually exclusive. In many application scenarios, they coexist, which can improve the overall success rate.

This part of the implementation below is not easy, encountered many, many challenges, we cut three aspects to illustrate one by one.

It has just been mentioned that the stability and compatibility of the UDP communication interface is strongly dependent on the bottom layer of the small program, and sometimes as the upper layer is very helpless, because it can not be controlled. However, it is not that nothing can be done. The corresponding error can be handled in three ways, including but not limited to:

• Evasive automatic processing scheme;

• Can do to remind users to operate;

• Feedback to wechat for continuous improvement.

These three steps have been done and there are successful cases, so many abstract, give some examples, such as:

Broadcast packets are sent regularly during one-click network configuration, and the frequency is very intensive, requiring between 5 and 10 milliseconds, so that the device side can properly parse the promiscuous mode monitor channel switch. However, when some Android phones send packets, it is found that some frequency can reach more than one second, causing the device cannot parse, and the success rate is very low.

When connecting to a device hotspot, some Android phones will not use the hotspot if the underlying layer determines that the hotspot does not have a Wi-Fi connection. However, UDP packets sent by the upper layer will not report an error, but the packet will be discarded.

When sending UDP packets, an error will be reported if you exit wechat and then open wechat distribution network.

The second challenge is that these vendors did not provide the SDK and source code for the applets when implementing the protocol for the one-click network. Because they have been developing for a long time, they do not have relevant network documents, and their own team is relatively short of experience in binary stream processing and encryption on the small program side.

In view of this dilemma, we sought authorization from the manufacturer together with our product classmates. The manufacturer provided SDK and source code or installation package of the APP side for us to interpret and translate, but the process was also troublesome. When debugging, we needed to run the APP, so as to compare the conversion results of the small program. There will be some interfaces supported by the APP, small programs do not support, such as small programs can not get the IP of the mobile phone, etc., we have combined the device side to solve these problems, also reflected in the overall network distribution process.

The third challenge is to locate the problem, because Wi-Fi network configuration is a long process involving the applets, routers and devices, and the process is also very long, which step is wrong, the device side or the applets side error need to have a strong ability to monitor. In this way, developers or C-terminal users can accurately and quickly locate problems when they feedback problems.

Because the importance of device side log is realized during the development and debugging, the small program log or the background log cannot quickly locate the problem. So how to collect logs on the device side, is there a general solution?

In the face of these challenges, we optimized the overall process of device-side Wi-Fi network, and also involved the solutions to the previous challenges.

At the beginning of the network configuration, the Wi-Fi failure rate is relatively high, with a failure rate of 2% to 3%. The failure also needs to allow users to manually connect on the system Settings page. If there is a manual connection, the network configuration process can continue, which increases the success rate to some extent.

Once successful, it is time to create UDP communication, which involves the difference between IOS and Android packets. At present, ES6 will be used when developing small programs. ES6 supports synchronous writing, but the writing method of mixing Promise and macro task (SetTimeout) on the small program side has a bug, resulting in a frequency of more than one second, not reaching 5 to 10 milliseconds.

Therefore, we send network packets in the asynchronous writing method of Android, while IOS still uses the elegant synchronous writing method to send network packets. After obtaining the packet return address of the device, we send the network of the device, and do so through UDP communication. It should be mentioned that this issue has been fixed in the new version of wechat.

UDP communication is connection-oriented and has the possibility of packet loss. Therefore, after the retry logic is designed, the entire process of binding devices ends. All processes are monitored for error events, and the entire operation track and error details are recorded.

When there is an error, we can judge the type of error and deal with some errors. For example, if Wi-Fi is switched during the actual network configuration, we can identify it and then add it to the correct Wi-Fi surface for automatic network configuration, which can also increase the success rate.

On the other hand, if there is an error, there is a common logic for collecting logs on the device side. The principle is not complicated, that is, a hotspot is set up on the device side, and the device side will send logs to the small program side after the phone side connects to the hotspot and passes the simple verification. After collected by the small program side, the holographic logs of the background, front end and device side will be stored in the log background. This log not only has the function of positioning, but also helps to analyze the success rate and time-consuming important information.

Auxiliary network configuration process, the device side will start a Bluetooth broadcast service, mobile phone side, small program side can connect to this Bluetooth, in the process of bluetooth communication, just Wi-Fi and UDP communication information can be exchanged.

Because all commands of ATT at the bottom of Bluetooth service are required, the reliability of the whole data transmission is very high. Now more and more modules are using this auxiliary distribution network. The downside, however, is that it costs twice as much as a pure Wi-Fi device.

BleCombo has one more step to connect the device to Bluetooth. As mentioned just now, the whole network configuration process will be logged to analyze the success rate and time consumption, so as to continuously improve the connection experience.

2. Bluetooth device access

The interaction process of Bluetooth devices on the cloud is very simple. After the mobile terminal or gateway is connected to the Bluetooth device, the Bluetooth device can exchange triplet information, and the mobile terminal can bind the device to the cloud after collecting it.

Bluetooth devices are suitable for some low-power and short-distance application scenarios, and can also support many-to-many communication scenarios. Location service and device network applications are suitable. However, the problem lies in low compatibility.

Low power Bluetooth compatibility is good, but classic Bluetooth is mediocre. Bluetooth is also becoming the dominant communication protocol for the Internet of Things.

Bluetooth devices challenges, one is the code in the design of the architecture, because open form have bluetooth bluetooth repeatedly plug-in, applied the SDK, and the custom of H5 SDK, bluetooth connection directly because the bluetooth device is a lot of, but each device and there is no universal bluetooth transmission protocol, are each own definition, Tencent lianlian also can not support every family, to customize the H5 open way, let developers to their own analysis of bluetooth protocol.

So how do you achieve reuse? Tencent repeatedly put bluetooth parsing logic in the every kind of bluetooth adapter, and some of the underlying logic, such as equipment management, process equipment binding some cloud logic and bluetooth connectivity and bluetooth state management logic as a at the bottom of the SDK, this right is at the bottom of the SDK, it is ok to go directly to install three open form, Protocol adapters that can be referenced on demand for Bluetooth parsing.

The second challenge is that in the process of Bluetooth communication, the MTU value will be exchanged at the bottom layer, but the small program side does not have a ready-made interface to obtain the MTU of the device side. As a result, the size of transmitted data cannot be determined. The device side can fragment and send data for parsing, but the small program does not know this, resulting in the device side fails to receive the large packet data.

To solve this problem, Tencent Lianlian added the MTU negotiation service on the device side, so that the small program side can get the MTU for manual sharding.

A third challenge is the debugging, because the resolution protocol has a lot of logic, and binary stream processing if need to be placed on real machine debugging, the efficiency is very low, our most basic habit can do is to change the code, code inspection exposed problems and so on, but behind the talk about the custom of H5 can be assisted in the browser debugging, to enhance the efficiency.

Iii. Capacity building and optimization of Tencent Lianlian equipment in interaction

1. Control panel classification

Tencent Lianlian’s control panel is mainly divided into three categories: standard panel, H5 personalized panel and development free panel. The H5 customization panel allows developers to render the entire panel by providing their own business logic in the design specification. Free development panel for more general model to make self-development panel, users directly use.

2. Customize the H5 solution

The bottom layer of custom H5 architecture is based on an H5 framework, opened in the small program embedded webView, from the bottom up, we provide limited application side API to the upper layer call, The middle layer through Bluetooth WebView forwarding and wechat JSSDK to provide wechat support for JSSDK calls in webView, such as scanning code and so on. The upper layer provides customized H5 development SDK, you can run JS, CSS generated by manufacturers.

The custom H5 architecture offers three broad categories of H5, device Control H5, standard/custom Bluetooth Device Search H5 and standard/custom Bluetooth Control H5. Custom Bluetooth search H5, search page to achieve device binding, standard and custom Bluetooth device control to do remote control and event reporting.

So how do you implement Bluetooth communication? Since H5 in WebView cannot communicate directly with Bluetooth, we designed a Websocket layer to forward Bluetooth messages, and the performance reached the millisecond level. The JS and CSS of the manufacturer can accept any technology stack, the whole process is the first debugging, release, after the background audit, after the external network visible, but also can be upgraded and rolled back.

Focus on debug mode, because debugging is very important to developers. Are a little open the entrance to a debug program, it can generate debug address H5, debug address can be WeChat open the browser and the public, verifies the console and login, to verify the current ID, generate a debug device ID, own generated JS agent with local manufacturers, so that you can render the page, Hot updates are also supported, which is the whole debug mode.

3. Stability, safety and performance considerations

As a framework for customizing H5, many things need to be guaranteed, such as stability. The framework of customized H5 uses SCF, which supports monitoring, automatic capacity expansion and real-time alarm analysis of ES system logs.

In terms of security, the whitelist of users should be limited during development and debugging, so that the pages of manufacturers cannot be seen by external users during development and debugging, which can ensure the security of codes and functions.

Application API also has permission restriction, can only control the device management interface of the manufacturer of the ProductID. Release also has audit, but also for manufacturers to upload JS security scan, the whole framework also has XSS, CSRF technology protection.

Iv. Introduction of Tencent’s open source capability

1. Open source ability

Tencent Link provides open source capabilities in three ways, one is the SDK for application development, the other is the small program plug-in, and the third is the custom H5SDK.

SDK for application development manufacturers can develop their own brand small programs based on this SDK. Tencent Lianlian has opened the API of technology distribution network and device management.

The significance of open source is to help people improve efficiency and reduce cost. There are many difficult and tedious parts in the whole equipment connection capacity construction and equipment control capacity construction introduced above.

The hard part can be done for the most part, but the tedious part takes a lot of time to polish, spend a lot of time testing and optimizing. We can solve the tedious part and the difficult part and open source it can improve the efficiency of users greatly, thus reducing the cost.

The Internet of Things is a very special field, and we need not only the success of one product, but also the success of the whole ecosystem. Tencent hopes to cooperate with the whole industry to build an ecology through open source.

Mr. Zhang Jianlin once said, “Maybe in the past five years, the Internet of Things and smart city you played is not the Internet of things thinking at all, but the LAN thinking, which is the dead city thinking. Your first-mover advantage is likely to be the martyr who sets out first.”

Tencent Cloud Internet of Things has been reflecting on itself with such worrying thinking, hoping to cooperate with everyone, collect everyone’s needs and generalize them to realize complementary functions, improve performance and improve experience, so as to lower the access threshold of developers, help locate customer problems and respond positively.

Many customers Tencent Cloud has contacted, including developers of the Internet of Things, have no front-end background, and some of them are from SCM development to front-end. We can also open some front-end ability guidance for such scenarios.

Q&A

Q: Tencent repeatedly follow-up will be a “touch is connected” yao, similar to NFC stick that kind of?

**A: ** is similar to the distribution network of two-dimensional code. We have plans to support it. The last one mentioned is the future planning, and we will carry out capacity building closely around the business needs of developers.

Q: How does Tencent lianlian guarantee large-scale involvement?

**A: ** Because Tencent Link is currently A C-terminal application, there are not many devices for each C-terminal user. The question should refer to whether Tencent Cloud’s message communication supports large-scale access? In fact, the scale of existing Internet of things devices is very large, but I will not disclose the specific number. At present, we support QoS0 and QoS1 guarantee, and concurrent QPS are also very large, and also have multiple disaster tolerance.

Q: Is Tencent Lianlian mainly used for smart home?

A: * * * * just began to apply the scene about equipment classification, applicable scenario is not pick, support is all kinds of communication protocol of access equipment, as to the equipment is used in which the business scenario is smart home, intelligent city, etc, have also launched tencent repeatedly enterprise board, help enterprise users to manage it such as the wisdom of building such A device to connect.

Q: What is the performance of Tencent Lianlian?

**A: ** just mentioned several dimensions, including device connection and device interaction, and each performance indicator is different. If you want to know what kind of performance is available, you can talk to me privately. More in-depth sharing also syncs performance data such as success rate and elapsed time, but I won’t post it today because I don’t have space. Do things must be boutique attitude to do, because support network protocol is also industry leading, I hope the performance of equipment connection is also industry leading, but this lead is also need to cooperate with everyone to achieve.

Q: Are apple and Android bluetooth connected?

* * A: WeChat is to provide such a * * is a wipe flatly differences of bluetooth interface, low power consumption performance reliability, we have access to the bluetooth device also has the evidence, is the classic bluetooth support, small program also see BBS, classic bluetooth is planned AnZhuoDuan support, IOS end system restrict couldn’t support, but the classic bluetooth is suitable for the audio communication and headphones, There are not many applications in the Internet of Things space.

The front end plays an important role in the Web. Web1.0 is the interaction between people and information, 2.0 is the interaction between people and 3.0 is not conclusive. In my opinion, 3.0 should be related to the Internet of Things, which is the interaction between people and things.

At present, the front-end of the Internet of Things is still few, and the Front-end of the Internet of Things needs c-end colleagues to join us to improve the experience of connecting and controlling devices at the C-end. I hope the front-end students who are interested in the Internet of Things can add my wechat to communicate with us.