This document specifies the design of a rangefinder to measure distances based on a PSOC (Programmable System-on-Chip) device of Cypress for two environmental applications: • Optimization of the addiction to the amount of product for the protection of plants during the growing season • Water level control for irrigation canals or water tanks The detection range is between 0.15 m and 1 m obtained through ultrasonic sensors, MA40B8S and MA40B8R, from Murata. Evaluation kit CY8CKIT-014 has been used in the the which contains PSoC CY8C5588AXI, both from Cypress, the last one is the most important component of the master, because on this device is set up, through PSoC Creator application, all the functions and objectives of the master. Giving more freedom in locating the rangefinder, it has been designed two prototypes: one which is the own rangefinder and another which receive the distance data, through wireless communication with AWP24S device from Artaflex, and send to a PC. Both designs are autonomous power supply through 9 V lithium batteries. Finally, it is implemented an application in LabView to represent graphically and store data in PC.