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Arduino Core for Nordic Semiconductor nRF5 based boards

Build Status OpenCollective OpenCollective

Program your Nordic Semiconductor nRF51 or nRF52 board using the Arduino IDE.

Does not require a custom bootloader on the device.


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Supported boards





Board Manager

  1. Download and install the Arduino IDE (At least v1.6.12)
  2. Start the Arduino IDE
  3. Go into Preferences
  4. Add as an "Additional Board Manager URL"
  5. Open the Boards Manager from the Tools -> Board menu and install "Nordic Semiconductor nRF5 Boards"
  6. Select your nRF5 board from the Tools -> Board menu

NOTE: During installation it takes the Arduino IDE a few minutes to extract the tools after they have been downloaded, please be patient.

OS Specific Setup


No additional setup required.


For 64-bit Linux users, libc6:i386, libstdc++6:i386, libncurses5:i386 and libudev1:i386 need to be installed :

  • sudo dpkg --add-architecture i386
  • sudo apt-get update
  • sudo apt-get -y install libc6:i386 libstdc++6:i386 libncurses5:i386 libudev1:i386
Driver Setup for mbed devices

Download mbed Windows Serial driver

Driver Setup for Segger J-Link
  1. Download Zadig
  2. Plugin Segger J-Link or DK board
  3. Start Zadig
  4. Select Options -> List All Devices
  5. Plug and unplug your device to find what changes, and select the Interface 2 from the device dropdown
  6. Click Replace Driver

NOTE: To roll back to the original driver go to: Device Manager -> Right click on device -> Check box for "Delete the driver software for this device" and click Uninstall

Driver Setup for Black Magic Probe
  1. Download .inf file drivers from blacksphere github
  2. Plugin Black Magic Probe
  3. Point the installer to the folder containing blackmagic.inf

NOTE: If using Windows 10 or Linux then two UART COM ports will be visible without requiring additional drivers

Selecting a SoftDevice

SoftDevices contain the BLE stack and housekeeping, and must be downloaded once before a sketch using BLE can be loaded. The SD consumes ~5k of Ram + some extra based on actual BLE configuration.

  • SoftDevice S110 v8.0.0 supports Revision 2 and 3 of nRF51 in peripheral role. It is 96k in size.
  • SoftDevice S130 v2.0.1 supports Revision 3 of nRF51 in peripheral and central role. It is 108k in size.
  • SoftDevice S132 v2.0.1 supports nRF52 in peripheral and central role. It is 112k in size.

Flashing a SoftDevice

  1. cd <SKETCHBOOK>, where <SKETCHBOOK> is your Arduino Sketch folder:
  • OS X: ~/Documents/Arduino
  • Linux: ~/Arduino
  • Windows: ~/Documents/Arduino
  1. Create the following directories: tools/nRF5FlashSoftDevice/tool/
  2. Download nRF5FlashSoftDevice.jar to <SKETCHBOOK>/tools/nRF5FlashSoftDevice/tool/
  3. Restart the Arduino IDE
  4. Select your nRF board from the Tools -> Board menu
  5. Select a SoftDevice from the Tools -> "SoftDevice: " menu
  6. Select a Programmer (J-Link, ST-Link V2, or CMSIS-DAP) from the Tools -> "Programmer: " menu
  7. Select Tools -> nRF5 Flash SoftDevice
  8. Read license agreement
  9. Click "Accept" to accept license and continue, or "Decline" to decline and abort
  10. If accepted, SoftDevice binary will be flashed to the board

From git (for core development)

  1. Follow steps from Board Manager section above
  2. cd <SKETCHBOOK>, where <SKETCHBOOK> is your Arduino Sketch folder:
  • OS X: ~/Documents/Arduino
  • Linux: ~/Arduino
  • Windows: ~/Documents/Arduino
  1. Create a folder named hardware, if it does not exist, and change directories to it
  2. Clone this repo: git clone sandeepmistry-github/nRF5
  3. Restart the Arduino IDE


This Arduino Core does not contain any Arduino style API's for BLE functionality. All the relevant Nordic SoftDevice (S110, S130, S132) header files are included build path when a SoftDevice is selected via the Tools menu.

Recommend BLE Libraries

  • BLEPeripheral
    • v0.3.0 and greater, available via the Arduino IDE's library manager.
    • Supports peripheral mode only.

Low Frequency Clock Source (LFCLKSRC)

If the selected board has an external 32 kHz crystal connected, it will be used as the source for the low frequency clock. Otherwise the internal 32 kHz RC oscillator will be used. The low frequency clock is used by the delay(ms) and millis() Arduino API's.

The Generic nRF51 and nRF52 board options have an additional menu item under Tools -> Low Frequency Clock that allows you to select the low frequency clock source. However, Nordic does not recommend the Synthesized clock, which also has a significant power impact.


This core is based on the Arduino SAMD Core and licensed under the same LGPL License

The following tools are used: