Reset button SW5 is connected to the interface MCU on the Development Kit (DK). It resets the nRF52840 System on Chip (SoC) or any device connected to the external programming connectors.
During normal operation, the button functions as a reset button for the nRF52840 SoC. For this to work, pin reset on P0.18 must be enabled in embedded firmware.
Note: Pin reset can be enabled by adding the
CONFIG_GPIO_AS_PINRESET variable to the compiler preprocessor macros. This depends
on the Integrated Development Environment (IDE)/toolchain in use:
- When using SEGGER Embedded Studio, go to and add the CONFIG_GPIO_AS_PINRESET variable.
- When using Keil, go to and add the CONFIG_GPIO_AS_PINRESET variable.
If your program does not enable pin reset, this functionality can also be
enabled on a previously programmed device by calling
nrfjprog.exe with argument
--pinresetenable. To disable pin reset again, reprogram
with --chiperase.