SMART DISTRIBUTED ENVIRONMENTAL MONITORING USING WIRELESS SENSOR NETWORK

Existing ad hoc network implementations are complex, costlier and lack flexibility due to requirement of monitoring equipment that are different depending on the surrounding environment. Therefore, a system is proposed to design a low cost wireless sensor network to measure temperature and relative humidity, to detect rain and the presence of CO gas. Anyhow, the node hardware can be easily arranged to detect also many different environmental conditions, thus, making the system flexible.
For determining temperature and relative humidity of atmosphere we are using DHT11 sensor. MQ7 sensor is used for detecting the ppm level of carbon monoxide gas in the environment, whereas FC-37 sensor is used for detection of rain. These 3 sensors are connected to the NodeMCU which is powered by a 9V battery or we can even use high capacity power banks to power the NodeMCU for better battery backup. Now, the nodes(comprising of NodeMCU, battery, DHT11, MQ7, FC-37) are placed in 3 different locations and data from each location is collected by the cloud servers. Here firebase is used for collecting DHT11, MQ7, FC-37 data and Ubidots is used for only collecting MQ7 data. Temperature and relative humidity values are used for predicting the weather condition like if temperature is less and relative humidity is more then there are chances of rain. Firebase database is integrated to the android application to make monitoring user friendly and also it gets rid of always opening the Firebase server through browser to monitor the data. To monitor data through android application, authorized user must enter secret login details(email ID and password). Once the entered login details are matched to the details saved in Firebase, we can monitor the data. In case if a authorized user forgets his password, the app provides a functionality to send a password reset link to the authorized email ID. This is done using Firebase’s API. An alert message is sent to the authorized user’s mobile number if carbon monoxide gas ppm level increases above 35 ppm. This is done using Ubidots. Firebase database is also integrated to Dialogflow which enables us to monitor the data of the nodes using Google Assistant.
Overall, environmental monitoring is a tricky activity as the environmental conditions can easily change from point to point even at small distances. This is especially true inside buildings where temperature, humidity, and pollutants can be different not only in different rooms but also within the same room especially when showcases and closed furniture are used. While several architectures have been proposed that can manage many sensing nodes, often there is low attention given to its flexibility and also they are quite costly. Therefore, the components developed within the framework described in this work is designed flexible enough to adapt to the change in different environmental parameters. It is a smart and simpler system with minimal cost which uses battery-operated sensors equipped with a wireless transmission protocol, which ensures real time monitoring.