Rain sensor using optical beam / Mohamad Husni Abdul Manaf

In this project report the design of a rain sensor using optical beam is discussed. This report describes the investigation of appropriate optical sensor and development of suitable circuit to detect visibility on vehicle windscreen. In order to build up automatic wipers, the concept of visibility is chosen for the rain sensor of the vehicles because the raindrop on windscreen gives different levels of visibility. The visibility detection can be made using infrared sensor since its ability to transmit and receive light effectively. The presence of water on the windscreen surface reduces reflected radiation while the presence of substrate increases reflected radiation. The sensor circuit designed produces different level of voltages depending on the visibility, that is the amount of liquid on the surface. The voltages are categorized into three different levels that will be sent to a microprocessor to control and activate wipers for intermittent, slow and fast movement.