Prototype research of watering machine in suitable humidity for vegetable plot Onion case study The objectives were to 1) design and develop a model of a watering machine in suitable humidity for vegetable plots. Onion case study 2) Determine the optimal location to place the moisture sensor of the watering machine model in the right humidity for the vegetable plot. Onion case study, Since manual watering with an uncontrolled sprinkler system results in inconsistent watering, it can lead to insufficiency of water throughout the area and underproduction of the onion, resulting in wasted excess water. Therefore, technology has been used in this research and a device has been developed to help in watering the onion plot. by bringing the sensor to develop and improve the sprinkler control to suit the onion plot. which the sensor can control the humidity according to the purpose and with absolute accuracy. The results of the experiments were 2 types of experiments. (1) Comparison of the operation of the two types of sensor systems, with sensor type 1 (Soil Moisure Sensor Module V 1) and type 2 (Soil Humidity Detection Sensor), by checking the operation of both types of sensors, from the data file on the Sd card, the results show that Soil Moisture Sensor Module v1 is more stable and receives faster and more accurate performance than type 2 sensor (2). When a suitable sensor is obtained from experiment 1, it is Sensor Type 1 (Soil Moisure Sensor Module V 1), by placing the sensor in Plot 1, placing the sensor 10 cm from the sprinkler, Plot 2, placing the sensor 30 cm from the sprinkler, Plot 3 placing the sensor 60 cm from the sprinkler. The results showed that plot 3 had the best growth, followed by plot 1 and plot 2, respectively. It was concluded that the sensor placed 60 cm from the springer had more onion growth than the sensor planted. Keep a distance of 10 centimeters and 30 centimeters from the sprinkler.