The pins allocated purpose
| GPIO | Function |
|---|---|
| 2 | Expansion Port |
| 3 | Expansion Port |
| 4 | Expansion Port |
| 5 | Expansion Port, Analog Output ALERT |
| 6 | Expansion Port |
| 7 | Expansion Port, Analog Output (CS0) |
| 8 | Expansion Port, Analog Output (CS1) |
| 9 | Expansion Port, Analog Output (MISO) |
| 10 | Expansion Port, Analog Output (MOSI) |
| 11 | Expansion Port, Analog Output (CLK) |
| 12 | Fast Transistor Output 1 |
| 13 | Fast Transistor Output 2 |
| 14 | RS-485 Tx_D, GSMLTE Modem (S_RXD) |
| 15 | RS-485 Rx_D, GSMLTE Modem (S_TXD) |
| 16 | Expansion Port, GSMLTE Modem (Powerkey) |
| 17 | Expansion Port, Analog Output (CS3) |
| 18 | RS-485 Direction Control, Digital Input & Transistor Output (IO Expander chip (INTERRUPT)) |
| 19 | Fast Transistor Output 3 |
| 20 | GSMLTE Modem (RESET) |
| 21 | GSMLTE Modem (STATUS) |
| 22 | Fast Input 4 |
| 23 | Fast Input 2 |
| 24 | Fast Input 1 |
| 25 | Fast Input 3 |
| 26 | Fast Transistor Output 4 |
| 27 | Analog Output (CS2) |
| SCL | |
| SDA | |
| SCL1 | IO Expander chip (Digital Inputs), IO Expander chip (Transistor Outputs), ADC chip (Analog Inputs 0-10V), Thermocouple Inputs |
| SDA1 | IO Expander chip (Digital Inputs), IO Expander chip (Transistor Outputs), ADC chip (Analog Inputs 0-10V), Thermocouple Inputs |
| HD1_P | GSMLTE Modem (USB_DP) |
| HD1_N | GSMLTE Modem (USB_DN) |
| HD2_P | |
| HD2_N |