The four buttons and four LEDs on the nRF52 DK are connected to dedicated GPIOs on the nRF52832 System on Chip (SoC).
| Part | GPIO | Short |
|---|---|---|
| BUTTON 1 | P0.13 | - |
| BUTTON 2 | P0.14 | - |
| BUTTON 3 | P0.15 | - |
| BUTTON 4 | P0.16 | - |
| LED1 | P0.17 | SB5 |
| LED2 | P0.18 | SB6 |
| LED3 | P0.19 | SB7 |
| LED4 | P0.20 | SB8 |
If P0.17–P0.20 are needed elsewhere, the LEDs can be disconnected by cutting the short on SB5–SB8. See the following figure for more information.
The LEDs and buttons can also be disconnected by using the I/O expander as described in I/O expander for buttons and LEDs.
The buttons are active low, which means that input is connected to ground when the button is activated. The buttons do not have an external pull-up resistor, so the P0.13—P0.16 pins must be configured as input with an internal pull-up resistor to use the buttons.
The LEDs are active low, meaning that writing a logical zero (0) to the output pin turns on the LED.
