1.4 The rise of the Internet of Everything
The connection between people has become increasingly close, at least in China, which is an indisputable fact. People's busyness has also reached an unprecedented level, when people's communication ability has become a bottleneck, and the way people exchange information with the outside world is nothing more than mouth, ear listening, eye viewing, finger tapping, and the transmission rate per second is nothing more than a few bytes. Therefore, when coordinating transactional work, human intervention greatly reduces the speed of data processing.
At this time, the Internet of Everything is emerging, which is the Internet of Things that we are learning now. In fact, he also has two other academic English names, one is called m2m and the other is called iOT. The full name of m2m is machine to machine, which is direct communication between machines. The full name of iot is the Internet of things, which is the Internet of Everything. This technology is to bypass people, directly establish communication between machines and machines, so that machines can maintain high-speed data transmission throughout the whole process, people are only responsible for data transmission rules, operation authorization, presentation of these work, thereby improving the operation efficiency of automation equipment.
In essence, the Internet of Everything is the embodiment of intelligent automation in human society. People's roles in many areas are shifting from direct participants in the social run to overseers of the social run. You may not believe it, but here I will give you an example. In the production line of chips, from the wafer to the final chip, there is almost no human participation. Don't say it's the factory workers, even the factory director, it's not clear how the intermediate steps are done. It is precisely because of the automation of the whole process that the chip can achieve the same price as cabbage. In fact, the whole society is the same, why our daily necessities are so cheap, this is done by a high degree of production automation, that is, complete de-artificialization. Thorough cross-regional automation must rely on high-speed, long-distance, and reliable m2m communication. That's what the IoT module does.
2 Introduction to IoT modules
Although the name of the IoT module sounds relatively unfamiliar, in fact, it does not have much mystery in itself, that is, a pcba (printed circuit board assembly), in layman's terms, it is a miniature circuit board. As a circuit board design, the design difficulty varies greatly depending on the type of circuit. In general, the higher the operating frequency, the higher the density, the greater the power, and the higher the signal accuracy requirements, the more difficult the design of the circuit. Like the Internet of Things communication circuit, because it involves high frequency, ultra-miniature, high sensitivity and other design goals at the same time, so the design difficulty is quite large, can be regarded as the "crown of the pearl" in the field of circuit design, just because the design is difficult, the general customer can not control, so the need for top-level design experts to complete. Since most customers cannot afford to independently design this part of the circuit, this part of the work is also independent, forming a subdivided industry.
The module is to put the high-precision high-density RF circuit and other logic control circuits with relatively low design difficulty independent of each other, and packaged on a miniature circuit board, which has become the Internet of Things module that we usually buy in the market. In general, the circuit inside the module adopts multilayer board, ultra-small volume original, and high-frequency impedance matching circuit design. After the IoT modules of regular manufacturers reach the design indicators, they must also pass rigorous performance tests and pass the certification of the Ministry of Industry and Information Technology before they can be sold in the market.
One IoT module = one ultra-high density pcba + one metal shield, image source: Hezhu Community doc.openluat.com
2.1 Ideal module
If there is such an object as an ideal module, as if Tang Monk will somersault, the entire IoT industry will have only one module. The ideal module would be an infinite transmission distance, an unlimited transmission speed, no delay in data, no energy consumption, and no money. Of course, this kind of object does not exist, the reason why we now have several different varieties of modules, mainly based on the following practical reasons 1 The transmission distance is not far enough, 2 The transmission speed is not fast enough, 3 The data delay is not low enough, 4 The module is not cheap enough, or need to pay data traffic fees, 5 Energy consumption is not small enough. Therefore, when users choose a module, they mainly have to consider the above points
2.2 The main performance indicators of the module
Usually the performance indicators mentioned in the data sheet are industry-specific indicators specified for the performance of a certain characteristic module, such as standby current, transmit power, and receive sensitivity. This article is a popular science article, and I did not intend to follow this routine. I'm going to talk about the performance metrics of the module from the perspective of the average user.