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Questions tagged [gatt]

GATT: Generic Attribute Profile

Provides profile discovery and description services for Bluetooth Low Energy protocol. It defines how a set of ATT attributes are grouped together to form services.

See Bluetooth Profile

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BlueZ 5.30: D-Bus GATT API - Simply Discover and Connect to a BLE device in C

With the last release of BlueZ (5.30) the highlight was the completion of the GATT D-Bus apis. My goal is to programmatically (in C), as a BLE client: scan for ble devices (which I can do with the hci layer) Connect to an advertising BLE device Get…
s2c97
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changing bluetooth low energy gatt timeout or flushing read stream to detect disconnect event quicker

I am looking for an android way to flush the characteristics the app receives from a Ble device, or at least know from the data that the connection has been lost as soon as it actually is except around 15 seconds after it disconnected. If there is a…
btelman96
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Bluetooth GATT disconnect onConnectionStateChange not called

I'm trying to implement my own timeout on my bluetooth GATT services by schedule a timer and call BluetoothGatt.disconnect() manually. But the callback is not called like what usually happen if the disconnect is triggered from the remote devices.…
Niko Adrianus Yuwono
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Reading multiple characteristics from a BLE device synchronously (Recommended Method for Android)

I am working on an android application which reads data from a BLE device. I came across plenty of solutions here on how to read multiple characteristics and most of them suggested Queues. I did implement the Queue method and everything is working…
Vikram Ezhil
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How to decode a Bluetooth LE Package / Frame / Beacon of a FreeTec PX-1737-919 Bluetooth 4.0 Temperature Sensor?

The Sensor advertises these Bluetooth LE Packages: > 04 3E 26 02 01 03 01 B8 AB C0 5D 4C D9 1A 02 01 04 09 09 38 42 42 41 43 34 39 44 07 16 09 18 47 08 00 FE 04 16 0F 18 5B B3 > 04 3E 26 02 01 03 01 B8 AB C0 5D 4C D9 1A 02 01 04 09 09 38 …
André Fiedler
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Understanding the GATT protocol in BLE

I have recently started to learn developing a mircocontroller-based device which will have BLE module. The device is supposed to send analog reading fetched from sensor to an android application that I am going to develop. For what i have studied…
user2045557
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How do you build a BLE app when you don't have access to the official GATT XML files?

To build a BLE app, you need service UUID the service's characteristic UUIDs the characteristic's permissions (read / write / notify ...) If you are sending any data, you need to know the value type (uint8_t, uint16_t ...) For an instance, if it…
kukrt
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Connect to gatt server not working on Samsung Galaxy Core Prime (Android 5.1.1)

I have a BLE app which works on devices with Android 6.0 and higher but I have issues on Samsung Galaxy Core Prime (Android 5.1.1). After calling connectGatt nothing happens and the callback receives only disconnected state. I have cut out…
Matej Procházka
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How to extract SFLOAT value from Bluetooth LE data for 1822 PulseOximeter using CoreBluetooth

I'm working on an iOS app that is to read pulse oximeter data from a Bluetooth LE enabled device, using CoreBluetooth on iOS 11.4 in Swift 4.1. I've got the CBCentralManager searching for peripherals, I find the CBPeripheral I am interested in, I…
drewster
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Looping 133 status in BluetoothGattCallback onConnectionStateChange

So I haven't been able to figure out what's causing this issue or how to work around it. I'm developing an app that stays connected to a BLE peripheral all day and collects data from sensors on the device. At times, the device will disconnect, and…
salbury
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Android Bluetooth LE - Read float characteristic

I am trying to read the float characteristic of a connected Bluetooth LE device(Genuino 101). For testing purposes, the device provides a FloatCharacteristic with the hardcoded Value '55.3'. While I am able to receive a string that somehow resembles…
UnbescholtenerBuerger
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Is it possible to establish multiple BLE connections to one GATT-Server?

Is it possible to have multiple GATT-clients connecting to one GATT-server? For example, a sensor can be the GATT-server. And I want to have multiple smartphones connecting at the same time, in order to access different services stored on the…
Noodles
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Android BLE: List of discovered characteristics in service is incomplete

Attempting to read characteristics from a GATT service, the list is incomplete compared to the list I get from an iOS device, or the manufacturer guide. I am reading the characteristics as follows: private final BluetoothGattCallback mGattCallback =…
zed
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Issues with Android Bluetooth Gatt Server/Client Simultaneous Connection

I am working on creating an app that can act as both a client and server for gatt connections simultaneously, but I am getting an unknown status and a disconnected state every time I run the server while it is behaving as a client. This is the…
user1634494
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GATTTool fails to read/write characteristics

I'm trying to use bluez's gatttool to write to some demo characteristics on a BLE custom board. Specifically I'm hoping to write to a characteristic and read the value back out. Here's what I'm doing (where 0x25 is the handle for the…
WKleinberg
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