Getting Started with nRF5340 DK

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A comprehensive guide to configuring and configuring the nRF5340 DK (PCA10095) for local development, differentiating between the application and network cores.

Introduction to the nRF5340 DK

The nRF5340 DK (PCA10095) is the premier single-board development kit for evaluating Nordic Semiconductor’s flagship nRF5340 System-on-Chip (SoC).

The nRF5340 is the world’s first wireless SoC with two Arm® Cortex®-M33 processors:

  1. Application Core (High Performance):
    • Arm Cortex-M33F running at up to 128 MHz.
    • Features DSP instructions, FPU, and Armv8-M TrustZone®.
    • Full feature set for complex application logic.
  2. Network Core (High Efficiency):
    • Arm Cortex-M33 running at a fixed 64 MHz.
    • Optimized for low-power wireless protocol handling (BLE, Thread, Zigbee).

Important: For general application development, you will primarily target the Application Core using the board target nrf5340dk/nrf5340/cpuapp.

General Preparation

To get started, ensure you have the following hardware and software stack:

Hardware

  • nRF5340 DK (PCA10095) connected via Micro-USB to the DEBUG port (labeled J2 on most boards, connecting to the on-board J-Link OB).

Software

  1. nRF Command Line Tools (includes SEGGER J-Link drivers).
  2. Development Toolchain:
    • VS Code (Recommended): Install the nRF Connect for VS Code extension pack.
    • Command Line: Python 3, Git, CMake, Ninja, and the Zephyr SDK (refer to the Zephyr Getting Started Guide).

Development in VS Code

The VS Code extension provides the most streamlined workflow.

  1. Setup Toolchain:

    • Open the nRF Connect sidebar.
    • Navigate to Toolchains / SDK management.
    • Follow the prompts to install the recommended nRF Connect SDK (NCS) version and toolchain.

  2. Create a Project:

    • Click Browse Sample or Create New Application.
    • Select zephyr/samples/basic/blinky for a quick test.

  3. Configure Build:

    • Click Add Build Configuration.
    • Board Target: Select nrf5340dk/nrf5340/cpuapp.
    • Tip: Ensure you don’t select cpunet unless you are specifically developing low-level radio firmware.

  4. Flash and Run:

    • Connect your DK.
    • Select the device in the Connected Devices panel.
    • Click Flash.
    • Observe LED1 blinking on the board.

For more details, consult the official nRF Connect for VS Code documentation.

Verification & Troubleshooting

Verifying the Setup

The blinky sample uses Zephyr’s device tree to automatically map the logical LED alias to the physical LED1 pin. No manual pin configuration is needed.

  • To change the blink rate, modify SLEEP_TIME_MS in src/main.c and re-flash.

Common Issues (FAQ)

1. Board not detected

  • Check connection: Ensure the cable is in the DEBUG port, not the nRF USB port.
  • Drivers: Reinstall nRF Command Line Tools / J-Link drivers.
  • Permissions (Linux): Verify udev rules are set up correctly.

2. Compilation fails / missing toolchain

  • Use the Toolchains / SDK management UI in VS Code to repair the installation. Ensure the toolchain version matches the SDK version.

3. LED not blinking

  • Wrong Core: Did you build for nrf5340dk/nrf5340/cpunet? The network core cannot directly control LED1 in standard configurations. Switch to .../cpuapp.

4. Identifying Serial Ports

When connected, multiple serial ports appear (e.g., /dev/tty.usbmodem... on macOS).

  • Run ls /dev/tty.* in the terminal.
  • If you see suffixes like 1 and 3:
    • 3 typically maps to the Application Core UART.
    • 1 typically maps to the Network Core UART.

Useful References