Raspberry Pi based photonics interrogator for fiber Bragg grating sensing applications in vending machines

Abstract

Optical fibre sensors and Internet-of-Things capabilities are attracting interest in many industries in recent years. Optical fibre sensors are being implemented as strain and temperature sensors where traditional electrical sensors have not performed well, like medical, transportation and infrastructure industries. Internet-of-Things capabilities are highly sought after as the world looks to automate many of their tedious and labour-intensive processes and to continuously weed out inefficiency in their work process. Such technology should not only be limited to specialised fields, both optical fibre sensors and Internet-of-Things have been successfully implemented in many areas and it is not too expensive to consider. To use optical fibre sensors and include the Internet-of-Things together on a machine that is commonly seen and used daily, like vending machine, is still largely unheard of. But, the benefits it can bring to the companies that manages the vending machines can be substantial to motivate them to adopt the integration of these technology into their products. In this project, it is investigated to see if optical fibre sensors can be made to detect weight change in a vending machine and use a Raspberry Pi to function as photonics interrogator to track the quantity in the vending machine and introduce the Internet-of-Things capabilities. Using an analog-to-digital converter to simulate the change from optical signals to voltage to digital readings, the readings will be used to determine the quantity of the product. The Raspberry Pi will be programmed to read values from the analog-to-digital converter and display the values on a web page that is hosted on an internal web server. The outcome is a successful web page display of real-time readings, and a database of all the past recorded readings. The quantities can be easily tracked on the web pages.