# Perform Bluetooth Low Energy GATT client functions Source: [https://docs.qualcomm.com/doc/80-70017-13/topic/bluez-perform-bluetooth-low-energy-gatt-client-functions.html](https://docs.qualcomm.com/doc/80-70017-13/topic/bluez-perform-bluetooth-low-energy-gatt-client-functions.html) You can perform Bluetooth Low Energy GATT client functions using the GATT submenu options and `bluetoothctl` commands. ## Connect to a remote device To connect to a remote device, run the following command from the `bluetoothctl` menu: connect Copy to clipboard **Parameters** `` is the Bluetooth address of the remote device. Note: To get the Bluetooth address of the remote device, run a [Bluetooth Low Energy GATT scan](https://docs.qualcomm.com/doc/80-70017-13/topic/bluez-perform-bluetooth-low-energy-gatt-client-functions.html#bluez-perform-bluetooth-low-energy-gatt-client-functions__section_oyf_kts_lcc_navyanka_08-21-24-1425-50-130). **Example** To connect to a server device with `` `6D:38:AF:C6:B5:62`, run the following command: connect 6D:38:AF:C6:B5:62Copy to clipboard **Sample output** [bluetooth]# connect 6D:38:AF:C6:B5:62 Attempting to connect to 6D:38:AF:C6:B5:62 [CHG] Device 6D:38:AF:C6:B5:62 Connected: yes Connection successful [NEW] Primary Service (Handle 0x0000) /org/bluez/hci0/dev_6D_38_AF_C6_B5_62/service0001 00001801-0000-1000-8000-00805f9b34fb Generic Attribute Profile [NEW] Characteristic (Handle 0x0000) /org/bluez/hci0/dev_6D_38_AF_C6_B5_62/service0001/char0002 00002a05-0000-1000-8000-00805f9b34fb Service Changed [NEW] Characteristic (Handle 0x0000) /org/bluez/hci0/dev_6D_38_AF_C6_B5_62/service0001/char0004 00002b3a-0000-1000-8000-00805f9b34fb Server Supported Features [NEW] Characteristic (Handle 0x0000) /org/bluez/hci0/dev_6D_38_AF_C6_B5_62/service0001/char0006 00002b29-0000-1000-8000-00805f9b34fb Client Supported Features [NEW] Characteristic (Handle 0x0000) /org/bluez/hci0/dev_6D_38_AF_C6_B5_62/service0001/char0008 00002b2a-0000-1000-8000-00805f9b34fb Database Hash [CHG] Device 6D:38:AF:C6:B5:62 UUIDs: 00001800-0000-1000-8000-00805f9b34fb [CHG] Device 6D:38:AF:C6:B5:62 UUIDs: 00001801-0000-1000-8000-00805f9b34fb [CHG] Device 6D:38:AF:C6:B5:62 ServicesResolved: yesCopy to clipboard ## Start Bluetooth Low Energy GATT scan To start a Bluetooth Low Energy GATT scan, run the following command from the `bluetoothctl` menu: scan leCopy to clipboard Note: To get the scan results, the remote device must advertise using any Bluetooth Low Energy application. **Sample output** [MyDeviceB]# scan le Discovery started [CHG] Controller 22:22:9B:2C:79:1E Discovering: yes [CHG] Device F8:7D:76:9D:9B:6B RSSI: -70 [NEW] Device A4:30:7A:EE:AF:EF [TV] MyDeviceA (43) [NEW] Device 52:2F:07:6F:AA:93 52-2F-07-6F-AA-93 [CHG] Device A4:30:7A:EE:AF:EF ManufacturerData Key: 0x0075 [CHG] Device A4:30:7A:EE:AF:EF ManufacturerData Value: 42 04 01 01 e7 a4 30 7a ee af ef a6 30 7a ee af B..... 0z....0z.... ee 01 3b 00 00 00 00 00 ...... [CHG] Device A4:30:7A:EE:AF:EF Modalias: bluetooth:v04E8p8080d0000 [CHG] Device A4:30:7A:EE:AF:EF UUIDs: 0000110a-0000-1000-8000-00805f9b34fb [CHG] Device A4:30:7A:EE:AF:EF UUIDs: 0000110b-0000-1000-8000-00805f9b34fb [CHG] Device A4:30:7A:EE:AF:EF UUIDs: 0000110c-0000-1000-8000-00805f9b34fb [CHG] Device A4:30:7A:EE:AF:EF UUIDs: 0000110e-0000-1000-8000-00805f9b34fb [CHG] Device A4:30:7A:EE:AF:EF UUIDs: 00001112-0000-1000-8000-00805f9b34fb [CHG] Device A4:30:7A:EE:AF:EF UUIDs: 0000111f-0000-1000-8000-00805f9b34fb [CHG] Device A4:30:7A:EE:AF:EF UUIDs: 00001200-0000-1000-8000-00805f9b34fb [CHG] Device A4:30:7A:EE:AF:EF ManufacturerData Key: 0x0075 [CHG] Device A4:30:7A:EE:AF:EF ManufacturerData Value: 42 04 01 01 e7 a4 30 7a ee af ef a6 30 7a ee af B..... 0z....0z.... ee 01 3b 00 00 00 00 00 ...... [CHG] Device A4:30:7A:EE:AF:EF ManufacturerData Key: 0xff19 [CHG] Device A4:30:7A:EE:AF:EF ManufacturerData Value: 00 75 00 09 01 00 00 00 06 01 00 00 00 00 00 00 .u.................. 00 00 00 00 00 00 00 00 ................ [CHG] Device F8:7D:76:9D:9B:6B RSSI: -60 [CHG] Device A4:30:7A:EE:AF:EF ManufacturerData Key: 0x0075 [CHG] Device A4:30:7A:EE:AF:EF ManufacturerData Value: 42 04 01 20 e7 20 0d 00 02 01 2b 01 01 00 01 00 B .. ..... ....... 00 00 00 00 00 00 00 00 ........ [CHG] Device A4:30:7A:EE:AF:EF ManufacturerData Key: 0xff19 [CHG] Device A4:30:7A:EE:AF:EF ManufacturerData Value: 00 75 00 09 01 00 00 00 06 01 00 00 00 00 00 00 .u............. 00 00 00 00 00 00 00 00 ....... [NEW] Device 4A:04:87:DF:CB:35 4A-04-87-DF-CB-35 [DEL] Device 52:2F:07:6F:AA:93 52-2F-07-6F-AA-93Copy to clipboard ## Stop Bluetooth Low Energy GATT scan To stop a Bluetooth Low Energy GATT scan, run the following command from the `bluetoothctl` menu: scan offCopy to clipboard **Sample output** [MyDeviceB]# scan off Discovery stopped [CHG] Device A4:30:7A:EE:AF:EF RSSI is nil [CHG] Device F8:7D:76:9D:9B:6B RSSI is nil [CHG] Controller 22:22:9B:2C:79:1E Discovering: noCopy to clipboard ## Get the list of attributes To get the list of attributes of the remote device, run the following command from the `menu gatt` menu: list-attributes Copy to clipboard **Parameters** `` is the address of the remote device. **Example** To list the attributes of the remote device with the address `6D:38:AF:C6:B5:62`, run the following command: list-attributes 6D:38:AF:C6:B5:62Copy to clipboard **Sample output** [MyDeviceB]# list-attributes 6D:38:AF:C6:B5:62 Primary Service (Handle 0x0000) /org/bluez/hci0/dev_6D_38_AF_C6_B5_62/service0001 00001801-0000-1000-8000-00805f9b34fb Generic Attribute Profile Characteristic (Handle 0x0000) /org/bluez/hci0/dev_6D_38_AF_C6_B5_62/service0001/char0002 00002a05-0000-1000-8000-00805f9b34fb Service Changed Characteristic (Handle 0x0000) /org/bluez/hci0/dev_6D_38_AF_C6_B5_62/service0001/char0004 00002b3a-0000-1000-8000-00805f9b34fb Server Supported Features Characteristic (Handle 0x0000) /org/bluez/hci0/dev_6D_38_AF_C6_B5_62/service0001/char0006 00002b29-0000-1000-8000-00805f9b34fb Client Supported Features Characteristic (Handle 0x0000) /org/bluez/hci0/dev_6D_38_AF_C6_B5_62/service0001/char0008 00002b2a-0000-1000-8000-00805f9b34fb Database HashCopy to clipboard ## Get attribute information To get the information of an attribute, run the following command from the `menu gatt` menu: attribute-info Copy to clipboard **Parameters** `` is the UUID or the attribute path. **Example** To get the information of an attribute with the UUID `00002b29-0000-1000-8000-00805f9b34fb`, run the following command: attribute-info 00002b29-0000-1000-8000-00805f9b34fbCopy to clipboard **Sample output** [MyDeviceB]# attribute-info 00002b29-0000-1000-8000-00805f9b34fb Characteristic - Client Supported Features UUID: 00002b29-0000-1000-8000-00805f9b34fb Service: /org/bluez/hci0/dev_73_F4_3F_FA_0A_DF/service0001 Flags: read Flags: write MTU: 0x0205Copy to clipboard ## Select an attribute To select the attribute using the UUID or path, run the following command from the `menu gatt` menu: select-attribute Copy to clipboard **Parameters** `` is the UUID or path of the attribute. **Example** - To select an attribute using the UUID `00006677-0000-1000-8000-00805f9b34fb`, run the following command: select-attribute 00006677-0000-1000-8000-00805f9b34fbCopy to clipboard **Sample output** Characteristic User Description [MyDeviceB]# select-attribute 00006677-0000-1000-8000-00805f9b34fb "Copy to clipboard **Parameters** `` is the value to be written. **Example** To write the attribute value as `0x11`, run the following command: write "0x11"Copy to clipboard **Sample output** [MyDeviceB:/service0028/char0029]# read 0b Attempting to read /org/bluez/hci0/dev_64_8C_C7_03_C4_B0/service0028/char0029 [CHG] Attribute /org/bluez/hci0/dev_64_8C_C7_03_C4_B0/service0028/char0029 Value: 22 22 [MyDeviceB:/service0028/char0029]# write "0x11" Attempting to write /org/bluez/hci0/dev_64_8C_C7_03_C4_B0/service0028/char0029 [MyDeviceB:/service0028/char0029]# read 0 Attempting to read /org/bluez/hci0/dev_64_8C_C7_03_C4_B0/service0028/char0029 [CHG] Attribute /org/bluez/hci0/dev_64_8C_C7_03_C4_B0/service0028/char0029 Value: 11 11 [MyDeviceB:/service0028/char0029]#Copy to clipboard ## Read a descriptor value To read a descriptor value, do the following from the `menu gatt` menu: 1. [Select the intended attribute.](https://docs.qualcomm.com/doc/80-70017-13/topic/bluez-perform-bluetooth-low-energy-gatt-client-functions.html#bluez-perform-bluetooth-low-energy-gatt-client-functions__section_orr_wsr_mcc_navyanka_08-25-24-052-26-396) 2. Read the selected attribute by running the following command: read 0Copy to clipboard **Sample output** [MyDeviceB]# select-attribute 00006677-0000-1000-8000-00805f9b34fb "Copy to clipboard **Parameters** `` is the value to be written. **Example** To write the attribute value as `0x11`, run the following command: write "0x11"Copy to clipboard **Sample output** [MyDeviceB]# select-attribute 00006677-0000-1000-8000-00805f9b34fb "Copy to clipboard **Parameters** `` is the value to be written. **Example** To write the attribute value as `0x11`, run the following command: write "0x11"Copy to clipboard 3. Enter `yes` when prompted to confirm writing. ## Turn on notifications for an attribute To turn on notifications for an attribute, do the following from the `menu gatt` menu: 1. [Select the intended attribute.](https://docs.qualcomm.com/doc/80-70017-13/topic/bluez-perform-bluetooth-low-energy-gatt-client-functions.html#bluez-perform-bluetooth-low-energy-gatt-client-functions__section_orr_wsr_mcc_navyanka_08-25-24-052-26-396) 2. Enable notifications for the attribute by running the following command: notify onCopy to clipboard You are notified of any changes to the attribute. **Sample output** [MyDeviceB:/service0028/char0029]# notify on [CHG] Attribute /org/bluez/hci0/dev_44_38_FB_67_B2_E2/service0028/char0029 Notifying: yes Notify started [CHG] Attribute /org/bluez/hci0/dev_44_38_FB_67_B2_E2/service0028/char0029 Value: 55 U [CHG] Attribute /org/bluez/hci0/dev_44_38_FB_67_B2_E2/service0028/char0029 Value: 88 . [CHG] Attribute /org/bluez/hci0/dev_44_38_FB_67_B2_E2/service0028/char0029 Value: 55 55 UU [CHG] Device D4:8A:39:78:27:41 RSSI: -74 [CHG] Attribute /org/bluez/hci0/dev_44_38_FB_67_B2_E2/service0028/char0029 Value: 55 U [CHG] Attribute /org/bluez/hci0/dev_44_38_FB_67_B2_E2/service0028/char0029 Value: 11 U [CHG] Attribute /org/bluez/hci0/dev_44_38_FB_67_B2_E2/service0028/char0029 Value: 66 fCopy to clipboard ## Turn off notifications for an attribute To turn off notifications for an attribute, do the following from the `menu gatt` menu: 1. [Select the intended attribute.](https://docs.qualcomm.com/doc/80-70017-13/topic/bluez-perform-bluetooth-low-energy-gatt-client-functions.html#bluez-perform-bluetooth-low-energy-gatt-client-functions__section_orr_wsr_mcc_navyanka_08-25-24-052-26-396) 2. Disable notifications for the attribute by running the following command: notify offCopy to clipboard **Sample output** [MyDeviceB:/service0028/char0029]# notify off [CHG] Attribute /org/bluez/hci0/dev_44_38_FB_67_B2_E2/service0028/char0029 Notifying: no Notify stoppedCopy to clipboard **Parent Topic:** [General Attribute Profile](https://docs.qualcomm.com/doc/80-70017-13/topic/bluez-gatt.html) Last Published: Dec 26, 2024 [Previous Topic Perform Bluetooth Low Energy GATT server functions](https://docs.qualcomm.com/bundle/publicresource/80-70017-13/topics/bluez-perform-bluetooth-low-energy-gatt-server-functions.md) [Next Topic Human Interface Device over GATT Profile](https://docs.qualcomm.com/bundle/publicresource/80-70017-13/topics/bluez-hogp.md)