Linux BLE

From Variscite Wiki

Scanning for BLE devices

Use btmgmt tool to scan for BLE devices and report their MAC address type (random vs public).

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

In this example a single BLE device was detected, having MAC address 74:B9:AB:CF:13:A9 and random MAC address type

Connecting to BLE devices

Use gatttool to connect to BLE devices. Pass "-t random" parameter if scan reported 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:~# 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]>