River Water Quality Analysis Using Arduino-Based Sensor of the Cikapundung River, Indonesia

River water is essential for people’s lives and environmental health. There is a need to manage river water to maintain river water quality. This research aims to develop a river water quality analysis system that is practical, easy, and capable of storage and processing using several sensors connected to a computer system. The tools used in this research are Arduino UNO R3 board and sensors. River water samples with various characteristics were taken from four spots of the Cikapundung River. The results showed that river water quality analysis can be done using sensor-based Arduino UNO R3. The temperature at the four spots ranges from 27–32oC and is included in the safe category for sanitation use. Judging from the turbidity factor, the turbidity value of river water is in the high category, namely 49.2–58.1 NTU, which is unsuitable for sanitary use. Regarding the TDS factor, the TDS range in river water is 150–222 ppm, indicating that river water is not polluted. Meanwhile, the pH value shows that the pH range of river water is alkaline and can be used for sanitation with a range of 7.93–8.16. This indicates that the water quality in the Cikapundung River that needs attention is the turbidity factor. It takes awareness of the surrounding community and government agencies to work together to improve the river’s environmental health sustainably.