1 Introduction GPS is short for GlobalPositioning System. It is a global positioning system that uses navigation satellites to measure time and distance. It has high precision, all-weather and global coverage. The application of GPS in clock countdown system can achieve high-precision time display function. GPS-based high precision, countdown card is a satellite time measuring technology,

Abstract: This paper describes the development and design of hardware/software for a new type of vehicle reverse radar product (Reversing Multimedia Visual Ranging Terminal). Firstly, the advantages and working principle of this product are introduced. It uses the universal car TV as display platform, combines the infrared reverse distance measuring module, the character overlay module, and the main control module for hardware design and software development. Key words: ultrasonic ranging

In recent years, the construction of highways has been progressing rapidly, so scientific management of highways is imperative. For example, the traffic statistics and analysis of vehicles can achieve effective control and management of highway load. At present, some methods of counting vehicles on highways are using ring induction coil detector. The detection system detects the signal with high pulse level, which is easy to amplify and filter.

Summary: This paper mainly introduces the design of a radio frequency identification reader based on MFRC500 of Philips company. First, the composition of the system and the characteristics of MFRC500 are introduced. Then, the design specification of antenna is given. Finally, the interface schematic diagram between MCU89C52 and MFRC500, the operation flow of Mifare card and the program of reading card are given. The Department

Introduction Temperature and humidity control is widely used in people's production and life. People use thermometers and hygrometers to collect temperature and humidity, and control temperature and humidity by manual operation of heating, humidification, ventilation and cooling equipment. This not only has low control accuracy and poor real-time performance, but also has a high labor intensity for operators. Even if some users use semiconductor diodes as temperature sensors, due to their interchangeability