Access to the nRF52840 General-Purpose Input/Output (GPIO)s is available from connectors P2, P3, P4, P5, P6, and P24.
The P1 connector provides access to ground and power on the nRF21540 DK.
Some of the signals are also available on connectors P7, P8, P9, P10, P11, and P12, which are on the bottom side of the Development Kit (DK). By mounting pin lists on the connector footprints, the nRF21540 DK can be used as a shield for Arduino motherboards (only 3.3 V Arduino boards) or other boards that follow the Arduino standard.
For easy access to GPIO, power, and ground, the signals can also be found on the through-hole connectors P13–P17.
Some pins have default settings:
- P0.00 and P0.01 are used for the 32.768 kHz crystal and are not available on the connectors. For more information, see 32.768 kHz crystal.
- P0.05, P0.06, P0.07, and P0.08 are used by the Universal Asynchronous Receiver/Transmitter (UART) connected to the interface MCU. For more information, see Virtual COM port.
- P0.09 and P0.10 are by default used by NFC1 and NFC2. For more information, see NFC antenna interface.
- P0.11–P0.16 and P0.24–P0.25 are by default connected to the buttons and LEDs. For more information, see Buttons and LEDs.
When the nRF21540 DK is used as a shield together with an Arduino standard motherboard, the Arduino signals are routed as shown in the following figure.
