Segger Tools

The firmware is set up to use the Segger RTT logging and debugging. Debug output is written using NRF_LOG et al and the makefile is set up to use the RTT logger.

Download the JLink tools at Segger

Debugging in macOS

Launch the JLinkExe in one terminal:

$ JLinkExe -if swd -device nrf52 -speed 4000

…then type connect to connect to the device.

Launch the JLinkRTTClient command in a separate terminal to view the RTT log. When you redeploy you have to relaunch the JLinkExe and JLinkRTTClientcommands.

info Tip

Download an improved JLinkRTTClient command from It will reconnect to the JLinkExe server whenever it is restarted.