Smartphone-based environmental sensing network using bluetooth low energy device
Date of Issue2016-05-13
School of Mechanical and Aerospace Engineering
Singapore-MIT Alliance Programme
Nowaday, smartphones play an imperative role in our daily lives. As smartphones have become more pervasive, the technology will move from “connecting people” to “connecting things”. Smartphones contain not only internal sensors but also some communication modules (i.e. Blutooth) to communicate with external sensing devices. The increasing popularity of smartphones, with their embedded sensing capability, provides an opportunity to collect sensing data on a large scale, that is useful to individuals for improving their daily lives. At the same time, wireless communication technology is able to connect external sensing devices to smartphone. In the indoor enviroment, wireless sensor nodes can be distribued to collect environmental information，which can be transmitted to smartphone wirelessly. The concept of indoor environmental sensing with smartphone requires the small size sensor node with low-power wireless communication module. After comparing different wireless communication modules, Bluetooth is selected in this project for the wireless sensor platform. Firstly, the average current draw of Bluetooth low energy chip is only 20 uA. Secondly, the maximum data rate (1Mbit/s) of Bluetooth Low Energy (BLE) chip can meet the requirement for most environmental sensors. Thirdly, the mobility of the smartphone allows the opportunistic communication with BLE based sensing devices. This thesis provides a detailed analysis of the pros and cons of combining Bluetooth Low Energy devices with smartphone. The research goal is to create a BLE communitoon framework to handle multiple bluetooth connections at the same time. The BLE commnunication framework contains the Android APP design and embedded BLE module programming. According to the experiment conducted in this project, the three sensor nodes are able to send data concurrently at the rate of 10Kbps to smartphone without data loss.