7941D2 Dual-Frequency Card Reader Module V1.2 with Wiegand WG26 34-pin UART IC and ID Buzzer. The 7941E card reader module integrates a high-performance card reader RF circuit and antenna, with a user-selectable UART interface. Rich application support, supporting various card reading operations Voltage: DC 5V; Current: 40mA; Supports 125kHz card reading; Interface: UART; Dimensions: 47 x 26 x 5mm; Operating temperature: -20°C to 70°C; EM4100 card reading distance: Greater than 8cm Connection Instructions Power supply: DC 5V. A linear power supply may provide better performance. HE D1 D0: Data output: Data 1, Data 0 Applicable range: NC; Card Type; 0X02 EM4100; 0X01 Mifar 1K; 0X03 Mifar 4K; 0X10 HID card; 0X11 T5567 type; 0X20 Second card; 0X21 ISO14443B standard; 0X22 Felicity card; 0X30 15693 tag; 0X50 CPU card; 0X51 Sector information; 0XFF keyboard data For example, the data received by the serial port tool is 02 0A 02 2E 00 B6 D7 B5 F2 03 The first byte, 0X02, indicates the start of data. The second byte, 0X0A, indicates the total data length is 10 bytes, including the start and end of data. The third byte, 0X02, indicates the card type is EM4100. The fourth to eighth bytes (0X2E 0X00 0XB6 0XD7 0XB5) read the card number; the fourth byte, 0X2E, indicates the hidden card number. The ninth byte, 0XF2, indicates the BCC check for the second to eighth bytes. The tenth byte, 0X03, indicates the end of data. Notice: Stay away from interference sources; strong interference may affect card reading. Selecting a linear power supply can increase the card reading distance and performance; a switching power supply can reduce the distance without affecting normal operation. The module operates normally within the 3-5V range; do not use higher voltages. This module generates high-frequency signals, which may interfere with analog ci