Air Defence System contains: (Three micro-controllers Atmega16) Radar, Wind_Speed meter, Missile_Launcher as inputs and Target_Serine, Alarm_Serine as outputs. Radar gives you the number of detected target, Wind_Speed meter gives you analog signal which is propotional to the measured wind speed, Missile_Launcher has 8 missiles; reads a digital value to determine which missile out of 8 should be launched. when radar detects target, sys immediately activates the Target_Serine. If the reading of radar indicates more than 8 targets; system activates Alarm_Serine.