Design And Implementation Of Internet Of Things Terminal Tester Adapter Board

With the gradual maturity of the related technologies of the Internet of Things,the massive,multi-type and multi-form Internet of Things terminals put forward higher requirements for the Internet of Things terminal test equipment.The existing terminal test equipment has a single function,and multiple sets of equipment need to be combined to complete the diversified test of the Internet of Things terminal.As a result,the system becomes complicated and unreliable,which not only reduces the reliability of the test,but also increases the cost.Relying on the national major special project "Research and Standardization of Key Technologies of the Internet of Things Terminal Evaluation Platform",a universal Internet of Things terminal tester is designed,which can complete a variety of terminal test projects through rich interfaces.It has high integration,high precision,strong compatibility and scalability.According to the requirements of the subject,the thesis designs and implements the power card and main control card of the Io T terminal tester.Analyze the functional requirements and performance indicators of the power supply card and the main control card by combining the test requirements of the Internet of Things terminal and the functions of the Internet of Things terminal tester.Based on requirements analysis,the design architecture of the power card and the main control card is proposed.The power card uses STM32 to control the low-cost step-down switching regulator LM2596 S,which realizes a programmable power output with high resolution,wide voltage range and large drive current.It achieves a wide voltage range and high Highprecision sine wave or rectangular wave output by high-performance DDS chip AD9854.In addition,data can be transmitted transparently through RS485 interface.The power card is connected to the infrared transceiver through the infrared interface to learn and send infrared control codes.Based on FPGA and ARM,a voltage acquisition module with adjustable FIR filter parameters is designed and implemented.ARM calculates the filter coefficients according to the filter indicators such as sampling frequency and cut-off frequency,quantizes the filter coefficients,and then sends them to FPGA for FIR filter configuration.FPGA controls ADC to collect voltage signals,and completes filtering operation.The lightweight Lw IP protocol stack is transplanted and optimized on ARM,the Ethernet transmission function is realized.In order to solve the problems of network congestion and memory leakage when the network is disconnected and reconnected,the hot swap function of network cable is designed and implemented by polling method to ensure the stability and reliability of Ethernet communication.The software on PC with simple operation and rich functions is designed,which can control the test process and analyze the data.In this subject,a test platform was built to test the functions of each module of the power supply card and the main control card.The test results show that the modules of the power supply card and the main control card studied in the thesis can work normally,and the performance indicators can meet the design requirements.