| serial number | pin | Pin direction | Remark |
| 1 | GND | Input | Module ground |
| 2 | VCC | Input | Positive reference of module power supply, voltage range: 3.3～5.5V DC |
| 3 | AUX | output | Used to indicate the working status of the module; the user wakes up the external MCU, and the output is low during the initialization of the power-on self-test
Level; (can be suspended) |
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| 4 | TXD | output | TTL serial port output, connected to external RXD input pin; |
| 5 | RXD | enter | TTL serial port input, connected to the external TXD output pin; |
| 6 | M1 | Input (very weak pull-up) | Cooperate with M0 to determine the 4 working modes of the module (not floating, if not used, it can be grounded) |
| 7 | M0 | Input (very weak pull-up) | Cooperate with M1 to determine the 4 working modes of the module (not floating, if not used, it can be grounded) |
| 11 | ANT | output | Antenna interface (high frequency signal output, 50 ohm characteristic impedance) |
| 12 | GND | - | Fixedly |
| 13 | GND | - | Fixedly |
| 14 | GND | - | Fixedly |
| 18 | NC | - | Empty feet |
| 19 | NC | - | Empty feet |
| 20 | NC | - | Empty feet |
| 21 | NC | - | Empty feet |
| 22 | RESET | Input | Module reset pin, low level trigger, it is recommended that customers use a single chip microcomputer connection, reset processing and resume work in unexpected situations
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| 23 | GND | - | Fixed ground |
| 24 | NC | - | Empty feet |
