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• Target: NXP i.MX RT1050 EVK board with the Bluetooth adapter plugged into the USB (J9) port.
  The Bluetooth <Target address> in the examples below is 04:7F:0E:31:B7:94.

• Host: Any computer with a Bluetooth interface, running Linux with the Bluetooth tools (bluez-utils) installed.
  The Bluetooth <Host address> in the examples below is BC:77:37:5C:32:57.

3.1. Test Connectivity

1. Power-on the NXP i.MX RT1050 EVK board and wait for the Linux to boot on the Target. Run the Bluetooth daemons in the background:

   Code Block
   ... / # hcid -n& [1] 97 hcid -n hcid[97]: Bluetooth HCI daemon / # sdpd -n& [2] 98 sdpd -n / #

2. Plug-in the Bluetooth adapter to the USB1 interface of the NXP i.MX RT1050 EVK board. Observe the messages like these in the Target console:

   Code Block

   usb 1-1: new full-speed USB device number 3 using ci_hdrc usb 1-1: Duplicate descriptor for config 1 interface 1 altsetting 5, skipping hcid[229]: HCI dev 0 regBluetooth: hci0: CSR: Unbranded CSR clone detected; adding workarounds and force-suspending once... isteBluetooth: hci0: CSR: Failed to suspend the device for our Barrot 8041a02 receive-issue workaround red hcid[229]: HCI dev 0 up hcid[235]: Can't set encrypt on hci0: Invalid request code (56) hcid[229]: Starting security manager 0

3. Get the <Target address> Bluetooth address of the adapter you have just plugged-in:

   Code Block
   / # hcitool dev Devices: hci0 04:7F:0E:31:B7:94 / #

4. Add the Serial Port profile to the list of Bluetooth profiles. In the example below the Bluetooth channel number to access this profile is 1:

   Code Block
   / # sdptool add --channel=1 SP Serial Port service registered

5. Start the background listening for raw connections on the channel 1:

   Code Block
   / # rfcomm --raw listen /dev/rfcomm0 1 & [3] 110 rfcomm --raw listen /dev/rfcomm0 1 / # Waiting for connection on channel 1

6. On the Host, open a raw Bluetooth connection to the Target (<Target Address> Bluetooth Device, channel 1):

   Code Block
   $ sudo rfcomm --raw connect 0 04:7F:0E:31:B7:94 1 Connected /dev/rfcomm0 to 04:7F:0E:31:B7:94 on channel 1 Press CTRL-C for hangup

7. In the Target console observe an indication of the connection from the Host:

   Code Block
   Connection from BC:77:37:5C:32:57 to /dev/rfcomm0 Press CTRL-C for hangup

8. Send a text string (command) to the Target over the Bluetooth serial port from the Host:

   Code Block
   $ echo "Hello from Host over the BT Serial" | sudo tee /dev/rfcomm0 Hello from Host over the BT Serial

9. On the Target receive the text string (command) just sent from Host:

   Code Block
   / # cat /dev/rfcomm0 Hello from Host over the BT Serial ^C

10. Send a text string (response) from the Target to Host over the Bluetooth serial port:

    Code Block
    / # echo "Hello from Target over the BT Serial" > /dev/rfcomm0

11. Receive the text string (response) just sent from the Target over the Bluetooth serial port:

    Code Block
    $ sudo cat /dev/rfcomm0 Hello from Target over the BT Serial ^C

12. Disconnect the Host from the Bluetooth serial line by pressing Ctrl-C in the rfcomm --raw connect ... terminal window:

    Code Block
    ^C Disconnected

13. Observe the rfcomm termination on the Target side:

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