Ultrasonic sensor moudle Low cost, small size, switching signal output For alarm system, proximity switch etc. . Ultrasonic sensor1.TU-001 Ultrasonic sensor ... setting value to a EEPROM chip. C. Detecting obstacleIf the system detects a distance less than this setting value, it will ... a relay, buzzer directly, or connected to a alarm system to active a alarm or action also. special mini ultrasonic ...