nRF52 Preview DK v1.1.x

Buttons and LEDs

The four buttons and four LEDs on the nRF52 PDK are connected to dedicated I/Os on the nRF52832 chip.

Table 1. Button and LED connection
Part GPIO Short
Button 1 P0.13 -
Button 2 P0.14 -
Button 3 P0.15 -
Button 4 P0.16 -
LED 1 P0.17 SB5
LED 2 P0.18 SB6
LED 3 P0.19 SB7
LED 4 P0.20 SB8

If GPIO P0.17–P0.20 are needed elsewhere, the LEDs can be disconnected by cutting the short on SB5SB8, see Disconnecting the LEDs. The LEDs and buttons can also be disconnected by using the I/O extender as described in I/O expander for buttons and LEDs.

Figure 1. Disconnecting the LEDs
Disconnecting the LEDs on SB5–SB8

The buttons are active low, meaning the input will be connected to ground when the button is activated. The buttons have no external pull-up resistor, so to use the buttons the P0.13–P0.16 pins must be configured as an input with an internal pull-up resistor.

The LEDs are active low, meaning that writing a logical zero ('0') to the output pin will illuminate the LED.

Figure 2. Button and LED configuration
nRF52 PDK button and LED configuration