Zephyr uses the thingy53/nrf5340 board configuration for building for the Thingy:53 board. The board has the nRF5340 MCU processor, a set of environmental sensors, a pushbutton, and RGB LED.

The nRF5340 is a dual-core SoC based on the Arm® Cortex®-M33 architecture, with:

  • a full-featured Arm Cortex-M33F core with DSP instructions, FPU, and Armv8-M Security Extension, running at up to 128 MHz, referred to as the application core

  • a secondary Arm Cortex-M33 core, with a reduced feature set, running at a fixed 64 MHz, referred to as the network core.

The thingy53/nrf5340/cpuapp build target provides support for the application core on the nRF5340 SoC. The thingy53/nrf5340/cpunet build target provides support for the network core on the nRF5340 SoC.

The Nordic Thingy:53 Hardware guide [1] contains the processor’s information and the datasheet.

Programming and Debugging


Flashing Zephyr onto Thingy:53 requires an external J-Link programmer. The programmer is attached to the P9 programming header.


Thingy:53 does not have an on-board J-Link debug IC as some other nRF5 development boards, however, instructions from the Nordic nRF5x Segger J-Link page also apply to this board, with the additional step of connecting an external debugger. A development board with a Debug out connector such as the nRF5340 DK can be used as a debugger with Thingy:53.