The nRF528540 Dongle is equipped with a green LED (LD1), a multicolor RGB LED (LD2), a user configurable button (SW1), and a reset button (SW2).
The LEDs and buttons are connected to dedicated I/Os on the nRF52840 SoC.
Figure 1. nRF52840 Dongle buttons and LEDs
| Part | Description | GPIO |
|---|---|---|
| SW1 | Button | P1.06 |
| SW2 | Reset | P0.181 |
| LD1 | Green | P0.06 |
| LD2 | Red | P0.08 |
| LD2 | Green | P1.09 |
| LD2 | Blue | P0.12 |
The buttons are active low, which means that the input will be connected to ground when the button is activated. The SW1 button has no external pull-up resistor, but the reset button (SW2) has a 10 k pull-up resistor. To use SW1, P1.06 must be configured as an input with an internal pull-up resistor.
The LEDs are active low, which means that writing a logical zero '0' to the output pin will illuminate the LED.