RFID读卡程序。硬件工作原理：基站在上电的情况下通过耦合线圈发射频率为125k的正弦波，ID卡的耦合线圈在125k的正弦波的激励下产生感应电动势，它为整个ID卡提供电源。ID卡通过调制电路根据其卡类的数据使ID卡的耦合线圈也发出正弦波，基站的耦合线圈接收到，根据它与125k波的不同来表示不同的数据。并将其通过DATA端以曼切斯特码的形式输出。-RFID reader program. Hardware it works: At the base station on the case of electricity through the coupling coil 125k launch the sine wave frequency, ID card at the coupling coil 125k inspired by the sine wave generated electromotive force sensors, which provide power throughout the ID card. ID card through the modulation circuit in accordance with its type of data card ID card issued sinusoidal coupling coil, the base station to receive the coupling coil, in accordance with the different wave 125k to express different sets of data. And Manchester, through DATA-side code in the form of output.