Smart inventory using acoustic and radio communications

Abstract: The world is getting connected in both small and bigger systems. Internet of Things (IoT) has flourished the past years and we no longer just connect our computers and phones but also our cars, wallets, keys and even the furniture and lighting in homes are talking. It is time to take things one step further, give your food and supplies a voice. This master thesis has the purpose to construct a smart inventory using the IoT. Its outcome is a prototype that consists of three main parts: 1) a number of sensor nodes to measure what products are left, 2) a hub to collect the inventory from the sensor nodes through acoustic communication and store it, and 3) an app on a mobile device to receive the inventory from a hub via Bluetooth and display it in a list for the user. The acoustic communication between the sensor node and the hub are thoroughly investigated taking into account the distance and angle as well as reliability. The Bluetooth communication between the hub and the mobile device with the app can be established automatically when the app is opened or when the user requests an update. The finished prototype has been tested and its performance evaluated. The results show that it functions with great satisfaction, being capable of measuring inventory, storing it and display it on the app. The sensor node and hub have highly reliable communicate within the distance of 1.9 m, a horizontal angle of 25 degrees and a vertical angle of 30 degrees. When the system is exposed to a lot of disturbance it has a reliability of 66% and the Bluetooth connection between the hub and the app can automatically connect about 70% of the times. This smart inventory system can be used in homes, storage rooms, offices, workshops and stores without Internet connection so that no one outside of Bluetooth coverage can get the information, or be expand with Internet connection so that the inventory can be updated anywhere and anytime around the world.