Design & Implementation Of Electric Bicycle Charging System Based On NB-IoT

We Chinese keep a huge amount of electric bicycles,so it will be bright prospects for developing one kind of Electric Bicycle Charging Station which combined with safe charging and centralized parking management function.In this paper,we select a new technology of NB-IoT mobile wireless sensor networks to construct low-cost metro charging station network in which we could control the charging piles by WPAN.This two-level wireless communication networking mode has high cost performance.Three optional login methods include facial recognition,fingerprint recognition and associate ID help to solve the charging problem when the smartphone cannot be used.Hall current measurement technology without insertion loss is able to meter charging accurately which makes users more assured of consumption.In order to realize the system function,we analyze the specific technical requirement after what we proposed the system general structure and functional structure of charging station and pile.The method to use NB-IoT technology,the selection of module and the realization of NB-IoT application are systematically analyzed and tested.At last,we designed detailed hardware circuit and related software program by reasonably choosing practical devices and modules.Considering the actual development of system and the market process,we respectively studied two terminal access modes for NB-IoT communication.The early start,we decided to build the system through One NET cloud platform for shorting the product development cycle.When the market matures,access Data Management and Analysis Center by TCP/UDP technology directly.The Measurement-Control Gateway of charging station is not only the terminal equipment of NB-IoT,but also the central node of WPAN in which modular structure is adopted in the circuit design.The primary MCU is STM32F407,cooperated with PHY chip through MII interface to constitute Ethernet interface,connect to the 4-in-1module of facial recognition,fingerprint recognition,ID-login and touch screen.Connect NB-IoT module and WPAN module by two serial communication interfaces.The modules of NB-IoT and the 4-in-1 function are already mature on market and the module of WPAN is a simplified version of the charging pile circuit so would make it more practicable and stable for the Measurement-Control Gateway.One piece of CC2530 chip is used in the charging pile Measurement-Control circuit to realize three functions: WPAN communication,charging control and sensor detection.Hall current sensor is chosen for adapting to ADC input,and we self-designed electric signal convertor circuit.One type of photoelectric smoke sensor is chosen which is a discrete component available on market.We self-built light-emitting driver and photoelectric detection circuit combined with software and hardware of CC2530 to achieve low-cost and high-performance smoke monitoring.There are 51 images,3 tables,66 references in this paper.