自己设计的一个双向防盗器，用315M的发射/接收头来发射和接收板，可以做车辆防盗用、家庭防盗等。51汇编，附电路图和PCB。-Designed a two-way alarm with the 315M Tx/Rx head transmitting and receiving plates, can be done with the vehicle anti-theft, home security, etc.. 51 compilation, with circuit diagram and