Sensor Driver Design Of Internet Of Things Node In Linux

Based on the application of the Internet of Things in the health monitoring of large structures,this paper designs the Internet of Things sensor system based on Zynq-7000 System-on-Chip.The programmable logic is used to provide the excitation signal for the actuator on the structure,and to collect the structural response signal obtained by the sensing element.The processor system is used to achieve data processing and network communications,so that to provide support for the dynamic characteristic test of large structures.This paper designs the Internet of Things sensor system based on Zynq-7000 System-on-Chip,it implements FPGA logic design and embedded Linux driver and application design.The work of this paper mainly includes the following four sections:1)The logic design of waveform generation module and data acquisition module,they will implement pumping signal output and response signal acquisition respectively;2)Achieving sensor device driver of user space based on UIO driver subsystem,to implement of character device file operation function and device memory mapping;3)Achieving sensor device driver of kernel space based on IIO driver subsystem,to implement user character device registration and file operation function,to achieve multi-level data cache;4)Developing embedded Linux application to achieve both data processing and network programming.The driver of user space based on UIO subsystem makes it possible for application to read from or write to the device memory directly,eliminating the time consumption caused by multiple system calls.We also achieved kernel space driver for data acquisition module based on the IIO subsystem,adding a new module to the IIO subsystem to register the user character device and implement the file operation function,we also realize the kernel data multi-level cache,it changes the data transfer mode of multiple " device-kernel space-user space" into once system call of " kernel space-user space " through multi-level cache,thereby enhancing the read efficiency.The experimental results show that the sensor device drivers in both ways can improve the efficiency of the sensor device accessing,and can realize high-speed data transmission.