Abstract : This system used Pyroelectric infrared sensor. Its manufacture is simple, and its cost is low, and fixing is convenient. Besides, the system has many merits, such as steady guard against theft, and strong antijamming ability, and high thesensitivity, and high reliability. The fixxing of this alarm is covert, which is discovered easily by cracksman. After has been processed by SCM, the signal of alarm communicates with PC, which is convenient for uniform management. This design includes hardware part and software part. The hardware part includes the control circuit of SCM, and the infrared probe circuit,and the alarm circuit, and LED control circuit. The SCM uses AT89C51, the overall system works under the control of the systemsoftware.
Key words: SCM; infrared sensor; data collection; alarm circuit