Design And Implementation Of CCD Spectral Acquisition Terminal Based On ESP32

In the field of visible light illumination,the failure of the production process or the aging of the lamp during using will result in too much blue light in the light source,which will cause certain damage to the human body.Therefore,it is necessary to perform spectral quality detection and analysis on visible light sources such as illumination lamps.However,most of the spectral instruments are traditionally integrated with the spectral data acquisition module and the spectral data analysis display module or connected through the USB interface.The overall size of the instrument is large and difficult to expand.There is also a spectrum instrument that separates the data acquisition module and the data analysis module based on WiFi for data transmission,but it requires an additional microcontroller for data acquisition.The WiFi module only performs data transmission,the resource utilization of the instrument is not high,and additional communication considerations of multi-microcontrollers need to be considered,thereby increasing design difficulty and resource consumption.In recent years,with the development of electronic technology and wireless communication technology,WiFi wireless communication chips have flourished,and ESP32 is an excellent WiFi chip.The ESP32 WiFi module has a built-in high-performance microcontroller that can be used to implement spectral data acquisition functions,and provides a wireless AP using its own WiFi function.The spectral data client can access the AP and establish a connection through the TCP protocol.So,both parties can perform signaling communication.Therefore,this paper only selects an ESP32 as the spectrum acquisition terminal microcontroller module,avoiding the introduction of additional microcontrollers to consume resources and increase design complexity.At the same time,the data acquisition module and the data analysis display module are separated and work independently.This paper introduces the design and implementation method of a CCD spectrum acquisition terminal based on ESP32,which is mainly used to help spectral data analysts to perform rapid spectral quality detection and analysis.Firstly,it introduces the research background and significance of the spectrum acquisition terminal,analyzes the development status of key technologies at home and abroad,and then introduces the related principles and key technologies involved in the spectrum acquisition terminal,including the working principle of the micro spectrometer and the MicroPython firmware driver and the IOT platform related component technology.Based on ESP32,the design and implementation of the spectrum acquisition terminal circuit is designed and implemented on the hardware.The modules such as ESP32 and spectrum sensor are integrated on one circuit board.In order to improve portability,the acquisition terminal is combined with the charging and discharging integrated module and lithium battery.It can work independently from the external power supply for a period of time;provide spectral data acquisition function,spectral data transmission function,and spectral data IoT cloud storage function on the software.In order to avoid the shortcomings of ESP32 directly using Python to complete the data acquisition module can not guarantee the spectral sensor timing,this paper uses MicroPython firmware to complete the sensor timing driver,obtain accurate spectral data,and provide a call interface to Python;in the process of spectral data transmission,this paper adopts select multiplex technology to listen multiple clients,and uses session technology to manage client sockets,avoiding frequent establishment and destruction of a connection with a client,consuming resources;due to the rise of IoT technology and the IOT cloud platform,and to make the spectrum acquisition terminal has a wider range of applications,and uses ESP32 to work in STATION mode,and uploads spectral data to the IOT platform through the MQTT protocol to realize cloud storage.Finally,the modules of the spectrum acquisition terminal are tested.The test results show that all modules of the system can operate normally and meet the functional design with good performance.