| Pin number | Name | Functions |
| 1 | VCC | The module power supply pin needs to be short connected to pin 2 to supply power to the module |
| 2 | 3.3V | 3.3V power pin |
| 3 | 3.3V | 3.3V power pin |
| 4 | VIO | MCU power supply pin, needs to be shortedto pin 3 to supply power to the MCU |
| 5 | GND | Base board reference ground |
| 6 | REST | MCU external reset pin |
| 7 | SWIM | MCU SWIM pin |
| 8 | VIO | MCU power supply pin |
| 9 | PC0 | Module reset pin |
| 10 | PB7 | Module MISO Pin |
| 11 | PB6 | Module MOSI Pin |
| 12 | PB5 | Module SCLK Pin |
| 13 | PB4 | Module NSS Pin |
| 14 | TXD | MCU Serial TXD |
| 15 | RXD | MCU serial RXD |
| 16 | M1 | Module mode switching pins (see module product manual for details) |
| 17 | GND | Base board reference ground |
| 18 | M0 | Module mode switching pins (see module datasheet for details) |
| 19 | GND | Chassis reference ground |
Product Descriptio