Blockchain technology is a distributed database `distributed ledger' and offers features such as autonomy, decentralisation and a trustless environment. These features make blockchain suitable to be applied to different applications within the Internet of Things (IoT) realm. This paper provides a practical implementation of Proof of Authority (PoA) Ethereum blockchain on an IoT system in a real-world use case. This implementation was practically accomplished in order to investigate and highlight some of the possible issues that could affect the integration of blockchain with IoT, to lay the ground for future research and possible solutions to these issues.