Smart bracelet, as a more popular form of product in the last two years, more and more attention from people, although it can not be accepted by all people, but its creation, it does make the electronic product market has produced some changes. Especially young people, the pursuit of fashion, but because the price is not pro-people. Although the smart bracelet hype is hot, but few people use it. To popularize the public, you also need to use PCB copy board reverse research technology.
A smart bracelet is usually composed of RF circuit unit, clock circuit unit, memory circuit unit, sensor circuit unit and main control MCU unit, etc., and the circuit PCB is usually concentrated in a smaller range, single-sided or double-sided SMD, circuit board copy board to 4 or 6 layers. We have to pay extra attention to the layout and wiring of the bracelet, and now summarize some notes for reference.
First, partition layout, pay attention to the alignment protection.
From the above PCB circuit board can be seen, the various parts of the smart bracelet circuit (marked by different color boxes) has a good partition: as the smart bracelet is a collection of digital circuit components together, in the PCB copy as long as the matching resistor and capacitor distribution, you can complete a certain function of the circuit module, which makes the PCB copy more concise and easy to find. Although some sensor circuit units use analog circuit technology for data acquisition, once the module is designed as a module, then the communication of data and the transfer of information can be completed through the corresponding connection interface.
In the layout of the circuit module, on the one hand, need to pay attention to the clock circuit and crystal circuit to go through the shortest path to reach the target tube teaching, on the other hand, in the clock alignment also pay attention to avoid data lines to prevent interference affect the stability of the system. In the alignment, the need for protection of key alignments, such as clock generation circuit, crystal circuit and so on whether the copper laying protection, whether the ring ground protection, etc., generally in the design will be protected, for the crystal part is required to dig copper processing.
Second, deal with the RF circuit.
Smart bracelet in use need to link with the phone, therefore, the radio frequency part is the key part, in this part of the design, must pay extra attention. Now the smart bracelet on the market is nothing more than wireless data transmission based on Bluetooth, so focus on the processing of Bluetooth RF. If the smart bracelet is only used for data transmission without the need for sound and music transmission, then low-power Bluetooth is the optimal choice, in the design, Bluetooth antenna shape, antenna layout, smart bracelet shell materials are important factors affecting the performance of the smart bracelet. In the smart bracelet PCB copy process, an excellent RF antenna engineer is particularly important.
Third, good ESD protection.
In previous articles I have also written some of the circuit ESD technology and knowledge, today it is important to say that the importance of ESD on smart bracelet products. Different countries and regions on different products or the same product ESD requirements have different standards, in order to make the product through the relevant testing, in the design of ESD protection design, after the design is completed, but also to carry out ESD testing to ensure that the product through the local market to adapt to the electronic testing.
Fourth, set aside system upgrade interface.
A smart bracelet is convenient to upgrade the function of the user or smart bracelet fanatic fans have an important significance. If a product at the appropriate time for software upgrades (may be pre-hardware design to certain functions and in order to catch up with the market software did not keep up, may also be to fix some software bugs), which indicates that the product is still in the process of non-stop research and development, which is a good psychological compensation for the user. Now there are usually two ways to upgrade the software of the smart bracelet: through the USB interface and wireless push method. As for which method to use, need to be in the pre-planning and hardware and software planning is to determine.
