The Design And Experiments Of Network Node Based On A New Monolithically Integrated Multichannel Spectral Sensor

Internet of things (IOT) is a kind of network based on the sensor technology and communication networks, in which almost everything in our life has the abilities of data processing and information exchange. Nowadays, IOT can sense many kinds of physical parameters except the chemical compositions. The near infrared spectroscopy is a fast and precise tool for the nondestructive analysis. By the spectral sensing node, IOT can have the analysis ability of chemical compositions. Compared with the large spectral analysis equipment, spectral sensing node has the advantage of miniaturization and low power consumption.The content of this thesis focuses on the design and performance of the spectral sensing node. First of all, the significance and prospect of the spectral sensing network was introduced. In this part, not only the development status and tendency of IOT, but also the near infrared spectroscopy are presented. The frequently-used technologies are compared to choose the suitable designing scheme. The spectral sensing node is based on a new monolithically integrated multichannel spectral sensor, which is developed by Shanghai Institute of Technical Physics of The Chinese Academy of Sciences. A multichannel integrated narrow-band filter array, an uncooled InGaAs detector array and a readout circuit are integrated into the spectral sensor, and its wavelength coverage is from 1350 nm to 1538 nm. A field programmable gate array (FPGA), functioning as a microcontroller unit, generates proper driving pulses for spectral sensor and controls the measurement process of spectrum signals. The wireless communication module is composed of an MSP430 family microprocessor and a transceiver IC nRF905 from Nordic Semiconductor. In order to check the precision of wavelength, a Xenon lamp and a laser diode (LD) with 1526.2 nm peak wavelength are used to evaluate the performance of the spectral sensing node. The performance of the spectral sensing node is proved to be stable and accurate.Benefiting from the monolithic design of the spectral sensor, the size and complexity of the spectral sensing node is reduced. The size of node is 9.0 cm×8.5 cm ×5.0 cm. The total supply current of the spectral sensing node is less than 60 mA, while the communication distance can be as long as 150 meters.