Developing a decentralized application using blockchain technology

Abstract

Blockchain is first introduced by Bitcoin [1] in 2009 and developers all around the world have been trying to apply Blockchain in different areas, like revolutionize finance services, credit and ownership management, resource sharing, investment management, IoT etc. Ethereum [2] is a Blockchain platform that allows developers to build a decentralized application without building a new Blockchain from the scratch. Internet of Things is the technology to embed all the physical devices with sensors and chips to provide automation process via machine-to-machine communication. Blynk is a platform that provides iOS and Android app for the users and developers to collect data from or control microcontroller. This project is aiming to build a system with Ethereum private Blockchain, Raspberry Pi, Blynk platform, DHT11 temperature and humidity sensors. The system is a prototype to simulate the smart home applications. It collects the real-time room temperature and humidity by DHT11 via Raspberry Pi. The sensor data will be updated to the Blynk App and stored on the smart contract deployed on the Ethereum private Blockchain. If the real-time temperature or humidity value exceeds the threshold value set by the users, red or green LEDs will be turned on as warnings. This system can be improved by some possible future work.