IMX Bluetooth Krogoth
Bluetooth boot messages
During boot the following Bluetooth kernel messages are received:
$ dmesg | grep -i Bluetooth Bluetooth: Core ver 2.18 Bluetooth: HCI device and connection manager initialized Bluetooth: HCI socket layer initialized Bluetooth: L2CAP socket layer initialized Bluetooth: SCO socket layer initialized Bluetooth: HCI UART driver ver 2.2 Bluetooth: HCI H4 protocol initialized Bluetooth: HCI BCSP protocol initialized Bluetooth: HCIATH3K protocol initialized Bluetooth: RFCOMM TTY layer initialized Bluetooth: RFCOMM socket layer initialized Bluetooth: RFCOMM ver 1.11 Bluetooth: BNEP (Ethernet Emulation) ver 1.3 Bluetooth: BNEP filters: protocol multicast Bluetooth: BNEP socket layer initialized Bluetooth: HIDP (Human Interface Emulation) ver 1.2 Bluetooth: HIDP socket layer initialized
Device identification
After the File system is up 'hciconfig' should show the connected bluetooth module.
hciconfig
hci0: Type: BR/EDR Bus: UART
BD Address: 64:A3:CB:5B:69:F0 ACL MTU: 1021:8 SCO MTU: 64:1
UP RUNNING PSCAN
RX bytes:1772 acl:0 sco:0 events:69 errors:0
TX bytes:1152 acl:0 sco:0 commands:65 errors:0
The hcitool can be used to show the Bluetooth MAC address of the Bluetooth module with the respective hci connection. Type help to show commands.
root@var-som-mx6:~# hcitool dev
Devices:
hci0 64:A3:CB:5B:69:F0
Connecting to classic Bluetooth devices
You can manage bluetooth with bluetoothctl, type 'bluetoothctl' and enter the interface. Type help to show commands.
For connecting a device do the following:
$ bluetoothctl [bluetooth]# power on [bluetooth]# agent on [bluetooth]# default-agent [bluetooth]# pairable on Push the connect button in the device (if exists) [bluetooth]# scan on Copy mac address [bluetooth]# scan off [bluetooth]# pair <mac address> Approve pairing on Device if required [bluetooth]# trust <mac address> [bluetooth]# connect <mac address> [bluetooth]# quit
For example when connecting a microsoft bluetooth mouse the following is done:
root@var-som-mx6:~# bluetoothctl
[NEW] Controller 50:72:24:11:EF:B0 BlueZ 5.37 [default]
[bluetooth]# power on
Changing power on succeeded
[bluetooth]# agent on
Agent registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# pairable on
Changing pairable on succeeded
[bluetooth]# scan on
Discovery started
[CHG] Controller 50:72:24:11:EF:B0 Discovering: yes
[NEW] Device 00:1D:D8:39:93:46 Microsoft Bluetooth Notebook Mouse 5000
[bluetooth]# scan off
[CHG] Device 00:1D:D8:39:93:46 RSSI is nil
Discovery stopped
[CHG] Controller 50:72:24:11:EF:B0 Discovering: no
[bluetooth]# pair 00:1D:D8:39:93:46
Attempting to pair with 00:1D:D8:39:93:46
[CHG] Device 00:1D:D8:39:93:46 Connected: yes
[CHG] Device 00:1D:D8:39:93:46 Modalias: usb:v045Ep0700d0100
[CHG] Device 00:1D:D8:39:93:46 UUIDs:
00001000-0000-1000-8000-00805f9b34fb
00001124-0000-1000-8000-00805f9b34fb
00001200-0000-1000-8000-00805f9b34fb
[CHG] Device 00:1D:D8:39:93:46 Paired: yes
Pairing successful
[CHG] Device 00:1D:D8:39:93:46 Connected: no
[bluetooth]# trust 00:1D:D8:39:93:46
[CHG] Device 00:1D:D8:39:93:46 Trusted: yes
Changing 00:1D:D8:39:93:46 trust succeeded
[bluetooth]# connect 00:1D:D8:39:93:46
Attempting to connect to 00:1D:D8:39:93:46
[CHG] Device 00:1D:D8:39:93:46 Connected: yes
[bluetooth]# hid-generic 0005:045E:0700.0001: unknown main item tag 0x0
input: Microsoft Bluetooth Notebook Mouse 5000 as /devices/soc0/soc.0/2100000.aips-bus/21e8000.serial/tty/ttymxc1/hci0/hci0:1/0005:045E:0700.0001/input/input1
Connection successful
[bhid-generic 0005:045E:0700.0001: input: BLUETOOTH HID v1.00 Mouse [Microsoft Bluetooth Notebook Mouse 5000] on 50:72:24:11:ef:b0
[bluetooth]# quit
[DEL] Controller 50:72:24:11:EF:B0 BlueZ 5.37 [default]
root@var-som-mx6:~#
Connecting to BLE devices
Connecting to BLE devices requires different command sequence. The btmgmt tool is used to scan for LE devices and report MAC address type (random vs public).
$ btmgmt find Copy MAC address of LE device, use "-t random" gatttool parameter if scan reports random MAC address. $ gatttool -b <MAC> [-t random] -I
For example when connecting to "BLE Peripheral Simulator" on Android phone the following is done:
root@var-som-mx6:~# btmgmt find Discovery started hci0 type 7 discovering on hci0 dev_found: 74:B9:AB:CF:13:A9 type LE Random rssi -90 flags 0x0000 AD flags 0x1a name Galaxy S5 hci0 dev_found: 00:1A:7D:DA:71:0B type BR/EDR rssi -79 flags 0x0000 name SMTBT hci0 dev_found: 00:1A:7D:DA:71:11 type BR/EDR rssi -96 flags 0x0001 eir_len 5 confirm_name succeeded for 00:1A:7D:DA:71:11 hci0 type 7 discovering off root@var-som-mx6:~# gatttool -t random -b 74:B9:AB:CF:13:A9 -I [74:B9:AB:CF:13:A9][LE]> connect Attempting to connect to 74:B9:AB:CF:13:A9 [74:B9:AB:CF:13:A9][LE]> Connection successful Indication handle = 0x0003 value: 01 00 ff ff [74:B9:AB:CF:13:A9][LE]>
Sending Files
Sending a file from the board to the bluetooth device using the obex transfer.
1) First, perform pairing with the device as described above. Ne need to establish connection
2) Start obexctl. Type help to show commands.
$ obexctl
3) connect to Device
[obex]# connect <mac addr>
4) Send a file from obexctl to the device
[<mac addr>]# send <file>
5) Once it's done, close the session
[<mac addr>]# disconnect [<mac addr>]# quit
For example, sending file to Ubuntu PC:
root@imx6ul-var-dart:~# obexctl
[NEW] Client /org/bluez/obex
[obex]# connect 00:1A:7D:DA:71:0B
Attempting to connect to 00:1A:7D:DA:71:0B
[NEW] Session /org/bluez/obex/client/session0 [default]
[NEW] ObjectPush /org/bluez/obex/client/session0
Connection successful
[00:1A:7D:DA:71:0B]# send /etc/fstab
Attempting to send /etc/fstab to /org/bluez/obex/client/session0
[NEW] Transfer /org/bluez/obex/client/session0/transfer0
Transfer /org/bluez/obex/client/session0/transfer0
Status: queued
Name: fstab
Size: 637
Filename: /etc/fstab
Session: /org/bluez/obex/client/session0
[CHG] Transfer /org/bluez/obex/client/session0/transfer0 Status: complete
[DEL] Transfer /org/bluez/obex/client/session0/transfer0
Receiving Files
Receiving files from paired devices is also supported. The files are stored under /tmp/bluetooth-inbox.