| .. _bluetooth-hci-spi-sample: | 
 |  | 
 | Bluetooth: HCI SPI | 
 | ################## | 
 |  | 
 | Overview | 
 | ******** | 
 |  | 
 | Expose Zephyr Bluetooth Controller support over SPI to another device/CPU using | 
 | the Zephyr SPI HCI transport protocol (similar to BlueNRG). | 
 |  | 
 | Requirements | 
 | ************ | 
 |  | 
 | A board with SPI slave, GPIO and Bluetooth Low Energy support. | 
 |  | 
 | Building and Running | 
 | ******************** | 
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 | You then need to ensure that your :ref:`devicetree <dt-guide>` defines a node | 
 | for the HCI SPI slave device with compatible | 
 | :dtcompatible:`zephyr,bt-hci-spi-slave`. This node sets an interrupt line to | 
 | the host and associates the application with a SPI bus to use. | 
 |  | 
 | See :zephyr_file:`boards/nrf51dk_nrf51422.overlay | 
 | <samples/bluetooth/hci_spi/boards/nrf51dk_nrf51422.overlay>` in this sample | 
 | directory for an example overlay for the :ref:`nrf51dk_nrf51422` board. | 
 |  | 
 | You can then build this application and flash it onto your board in | 
 | the usual way; see :ref:`boards` for board-specific building and | 
 | flashing information. | 
 |  | 
 | You will also need a separate chip acting as BT HCI SPI master. This | 
 | application is compatible with the HCI SPI master driver provided by | 
 | Zephyr's Bluetooth HCI driver core; see the help associated with the | 
 | :kconfig:`CONFIG_BT_SPI` configuration option for more information. | 
 |  | 
 | Refer to :ref:`bluetooth-samples` for general Bluetooth information, and | 
 | to :ref:`96b_carbon_nrf51_bluetooth` for instructions specific to the | 
 | 96Boards Carbon board. |