LCD1602 is used as the display screen in this system. In LCD1602, the first line shows the ambient temperature and infrared detection data, where the temperature is accurate in one place. The second line of the LCD1602 display realizes the rotation level of the current fan. Because there are many interfaces and regular data transmission ports in single-chip microcomputer, the port P0 is directly used as the data port of single-chip microcomputer, which makes the production of circuit board more convenient. Due to the weak driving ability of the iop0 port of the single chip microcomputer, it can be seen in the minimum system diagram of the single chip microcomputer that there is a pull-up on the P0 port. The specific connection diagram between lcd160 2 and MCU is shown in 2.4 in the figure