MCU为整个系统的核心，控制着整个系统的运行，让MCU稳定的运行是非常必须的，MCU原理图如图2.2所示。MCU控制部分主要由STM32F103RBT6、晶振电路、复位电路、启动模式选择电路、独立按键电路以及LED指示组成。电源部分包括一个后备电源BAT1，一个主电源VCC3.3和一个模拟电源，模拟电源通过从VCC3.3加LC滤波电路得到。-MCU as the core of the entire system, controls the operation of the system as a whole, so that the stable operation of the MCU is very necessary, as shown in MCU schematic is shown in Figure 2.2. MCU control part is mainly composed of STM32F103RBT6, crystal oscillator circuit, reset circuit, the startup mode selection circuit, composed of independent key circuit and LED indicator. The power supply section includes a back-up power BAT1 a main power VCC3.3 and an analog power supply, analog power through get from VCC3.3 an LC filter circuit.