A smart Bracelet usually consists of RF unit, clock circuit, memory circuit unit circuit unit, sensor circuit unit and MCU control unit and other components, and the circuit of PCB are usually concentrated in a small range, for single or double sided patch, circuit board for 4 or 6 for the lord.
First, the layout of the layout, pay attention to line protection.
From the PCB circuit board above can be seen in various parts of the circuit of smart Bracelet (different color box mark) have a good partition: because the smart bracelet is a digital circuit elements together in circuit design as long as the good resistance and capacitance distribution matching, circuit module can complete some functions, which makes the circuit design more concise and easy to find. Although some of the sensor circuit unit using analog circuit technology for data acquisition, once the module is designed as a module, then through the corresponding connection interface to complete the data communication and information transmission.
In the circuit layout, on the one hand need to pay attention to the clock circuit and oscillator circuit through the shortest path to reach the goal of discipline, on the other hand, the clock line must pay attention to avoid the data line, to prevent interference affects the stability of the system.
In the line, the need for the protection of key line, such as clock generation circuit, crystal oscillator circuit etc. are copper protection, whether ring protection, generally in the design of protection, for part of the crystal is to dig copper processing.
Second, deal with RF circuit
Smart Bracelet in the use of mobile phones and need to be linked, therefore, the radio frequency part is a key part of this part of the design, we must pay special attention to. Now the market is no more than the smart bracelet is based on Bluetooth wireless data transmission, so the focus of Bluetooth radio frequency processing. If the smart bracelet is just used for data transmission without the need for transmission of voice and music, so low power Bluetooth is the best choice in the design of Bluetooth antenna, antenna shape, layout, smart Bracelet shell materials are the important factors influencing the performance of smart bracelet.
Again, do ESD protection
In the previous article, I also wrote some of the technical aspects of the circuit ESD and knowledge, today, said the importance of ESD smart Bracelet products. Different countries and regions have different standards for different products or products of the same ESD requirements, in order to make the products through the relevant test in the design of ESD protection design, but also for the detection of ESD after the design is completed, to ensure the products meet the electronic detection of the local market.
Finally, the system upgrade interface.
Whether the function of a smart bracelet is convenient for users to upgrade or smart Bracelet enthusiasts have important significance. Now there are two ways to upgrade the smart Bracelet: USB interface and wireless push method. As to which approach to use, the need for early planning and software and hardware planning is to be identified.