Research And Implementation Of Wireless Charging Communication System Based On Qi Standard

With the popularization of electronic products such as smart phones and tablets,people’s life is more convenient and richer than before.The development of technology makes their functions more and more powerful,and the experience brought to users is also upgrading.But at the same time,it also increases the power consumption of equipment,users need to charge all kinds of equipment frequently every day.The traditional way of Hot-Plug charging,charging inconvenient problem is becoming increasingly prominent,all kinds of chargers and data lines make people tired,but also caused a waste of resources.As a new charging method,there is no physical direct connection between equipment and charger,which overcomes the disadvantages of traditional charging method and makes the charging process more flexible,convenient and safe.Based on the advantages of wireless charging technology,it has a wide range of application prospects in mobile devices,household appliances,industrial automation,medical implants and wearable devices,so it has attracted more and more attention.Based on the most popular wireless charging specification Qi standard in the field of wireless charging technology,this paper deeply studies the communication related content in the protocol,analyzes the communication principle and implementation mechanism between the transmitter and the receiver,and designs and implements a set of communication modulation and demodulation scheme.The scheme mainly adopts digital implementation,which has the characteristics of high efficiency,stability and easy transplantation.The specific contents of this paper are as follows:(1)This paper introduces the research status of wireless charging technology at home and abroad,and briefly describes the principle and implementation of three kinds of wireless charging technology.Then it introduces the current three mainstream wireless charging standard organizations and their wireless charging standards,and focuses on the analysis of Qi standard and its communication process.(2)According to the communication principle and signal modulation characteristics of Qi standard,the theoretical analysis and system modeling of the whole communication system are carried out.Compared with the existing demodulation schemes,an optimized scheme is proposed,in which the transmitter uses quadrature demodulation to realize digital ASK demodulation,and the receiver uses optimized width measurement method to realize digital FSK demodulation.(3)Complete the hardware circuit design and software design.In the part of hardware circuit,the design of communication circuit between transmitter and receiver is completed.The RTL design of digital circuit is mainly introduced,including three modules: digital ASK demodulator,PWM&FSK generator and digital FSK demodulator.In the part of system software,the software architecture of wireless charging communication is designed,and the system control program and the driver of each hardware module are completed.(4)Function verification of digital circuit,three digital circuit modules are simulated and verified by EDA tools.The function test points are decomposed by the module characteristics and working scenarios,and the verification environment is built.The modules are verified according to the test points,and the verified errors are modified.(5)The system test platform is built based on FPGA development board and peripheral circuit board.In the test,five factors that may affect the effect of communication demodulation are classified and verified,and then the test results are analyzed.The system optimization is completed,and the function of pattern recognition is added to improve the success rate of communication demodulation.The final test results show that the system can work normally,and the communication demodulation effect is good,which verifies the feasibility of this scheme.This paper has reference significance for the research and commercialization of wireless charging.