Manufacturing temperature and turbidity sensor based on ATMega 8535 microcontroller

The manufacturing of temperature and turbidity measurement system based on ATMega 8535 microcontroller has been done. To measure temperature, this system uses LM35 and photodiode to measure water turbidity. The principle of LM35 sensor is comparing temperature based on its resistance. Thus temperature that is converted to voltage can be detected. The Turbidity system in this experiment is using Nephelometer method with the light scattered by suspended particles in fluid, with LED and photodiode parallel to each other. This system can measure turbidity in 1 NTU – 200 NTU with a close distance (1 inch) and a maximum relative error of 3.09% for the temperature measurement and also 3,12 % for turbidity measurement.