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BlueZ: How to set up a GATT server from the command line

I would like to know if there is a way to set up a gatt server from the Linux command line. I know that the BlueZ gatttool command allows you to act as a gatt client and interrogate a remote gatt server, however, I do not think that this tool can be used to set up a server.

What I want to achieve is a gatt server, created from the command line, and can be interrogated by any central device (e.g. iOS or Android device) to connect to the GATT server, discover the services and characteristics, and manipulate the data in the characteristics.

Example:

Gatt Server with 1 service which contains 3 characteristics.

  • Service uuid = 0xFFFF
  • Char 1 uuid = 0xAAAA, value = 01, properties = readable
  • Char 2 uuid = 0xBBBB, value = 00, properties = readable & writable
  • Char 3 uuid = 0xCCCC, value = 02, properties = notifiable

I am using kernel version 3.11.0 and BlueZ 5.19

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Youssif Saeed Avatar asked Aug 21 '14 13:08

Youssif Saeed


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What is GATT server Bluetooth?

GATT is an acronym for the Generic ATTribute Profile, and it defines the way that two Bluetooth Low Energy devices transfer data back and forth using concepts called Services and Characteristics.

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1 Answers

So this is now handled with the new bluetoothctl tool. A gatt table can be set up using this tool as follows:-

#bluetoothctl
[bluetoothctl] menu gatt
[bluetoothctl] register-service 0xFFFF # (Choose yes when asked if primary service)
[bluetoothctl] register-characteristic 0xAAAA read       # (Select a value of 1 when prompted)
[bluetoothctl] register-characteristic 0xBBBB read,write # (Select a value of 0 when prompted)
[bluetoothctl] register-characteristic 0xCCCC read       # (Select a value of 2 when prompted)
[bluetoothctl] register-application # (This commits the services/characteristics and registers the profile)
[bluetoothctl] back
[bluetoothctl] advertise on

I've tried this with a few service/characteristic combinations and was able to get it to work. The GAP (0x1800) and GATT (0x1801) services are available by default and will be part of the GATT table when you advertise. You can also use the following command to see the available services:-

[bluetoothctl] show
Controller 00:AA:BB:CC:DD:EE (public)
    Name: MyMachine
    Alias: MyMachine
    Class: 0x000c0000
    Powered: yes
    Discoverable: no
    Pairable: yes
    UUID: Headset AG                (00001112-0000-1000-8000-00805f9b34fb)
    UUID: Generic Attribute Profile (00001801-0000-1000-8000-00805f9b34fb)
    UUID: A/V Remote Control        (0000110e-0000-1000-8000-00805f9b34fb)
    UUID: Generic Access Profile    (00001800-0000-1000-8000-00805f9b34fb)
    UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
    UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)
    UUID: Audio Source              (0000110a-0000-1000-8000-00805f9b34fb)
    UUID: Audio Sink                (0000110b-0000-1000-8000-00805f9b34fb)
    **UUID: Unknown                   (0000ffff-0000-1000-8000-00805f9b34fb)**
    UUID: Headset                   (00001108-0000-1000-8000-00805f9b34fb)
    Modalias: usb:v1D6Bp0246d0532
    Discovering: no
like image 54
Youssif Saeed Avatar answered Sep 23 '22 16:09

Youssif Saeed