The Colombian National Army conducts military operations against armed groups aimed at defending sovereignty, independence and territorial integrity. One of the armed groups strategies involved the creation of groups called “pisa-softs”, whose mission was to infiltrate the patrols and kill the sentinels. Various responses were developed to stop this type of attacks; One of them makes use of technological tools with programmable electronic devices and the use of sensors. A review of perimeter activity detection devices to detect intruders with systems applicable to hostile environments to define the most practical technology for building an effective device usable in the military posts. Subsequently, the functional modules of the device were defined, including a PIC microcontroller, a module with four infrared sensors, a receiving module and a tablet under Android for enhanced Tablet can be used for its construction. The result is a tool capable of generating a tactical advantage to military posts with a data reception at 60 ± 5 m and high sensitivity of 80% to 90% for intrusion detection.