---
id: rak-gpio-mapping
title: RAK GPIO Pin Mapping
sidebar_label: RAK GPIO Mapping
sidebar_position: 5
---

## RAK GPIO Pin Mapping

The RAK4631 uses symbolic labels for its I/O Pins on the module and baseboard silk screens. The following table shows the mapping of the RAK4631 GPIO pins to the corresponding Arduino pins and the MCU Port numbers.

| RAK Pin | nRF52840 Pin | Arduino GPIO | Remark                                                                   |
| ------- | ------------ | ------------ | ------------------------------------------------------------------------ |
| IO1     | P0.17        | 17           | used for GPS PPM signal if GPS module is connected                       |
| IO2     | P1.02        | 34           | used to power all peripheral modules, not available for user application |
| IO3     | P0.21        | 21           |
| IO4     | P0.04        | 4            |
| IO5     | P0.09        | 9            | The 'User Button' is mapped here.                                        |
| IO6     | P0.10        | 10           |
| IO7     | P0.28        | 28           |
| SW1     | P0.01        | 1            |
| A0      | P0.04/AIN2   | A2           |
| A1      | P0.31/AIN7   | A7           |
| SPI_CS  | P0.26        | 26           |

When configuring GPIO pins in your device settings, the Arduino GPIO numbers should be used.

```shell title="Example"
meshtastic --set external_notification.output 10
```

This will use IO6 on a RAK4631

:::caution Note
There is no usable GPIO pin on any RAK base board except the 'big' baseboard RAK19001 without adding a RAK13002 IO module or a third party IO sensor breakout.
:::
