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Questions tagged [bluetooth-gatt]

The Generic Attribute Profile (GATT) defines the way that two Bluetooth Low Energy (BTLE) devices transfer data back and forth using concepts called Services and Characteristics.

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Why Android BLE gatt callback method onCharacteristicChanged callback is called in lower rate in Wear OS device than on smartphone?

I develop an application designed for Wear OS devices that received data using BLE as Gatt client. I set the mtu size the maximum possible (517 bytes), and need to transfer some large amount of data - so I set the connection priority to…
user2993539
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Decode Ble data raw flutter

I'm developing a flutter app using the flutter_blue library to interface a BlueNRG-tile from STMicroelectronics. I'm receiving the the raw data from the desired caracteristics then i'm note able ble to convert them to string using the utf8.decode()…
thilor
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BLE Heart Rate Senser Value Interpretation

I have an Android App where I get Heart Rate Measurements from a Polar H10 Device. I'm totally lost on how to interpret the heart rate. Various links to the bluetooth.com site are resulting in 404 errors unfortunately. The characteristics value is…
Emanuel
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Getting Exception when calling notifyCharacteristicChanged() on GattServer

calling notifyCharacteristicChanged() will throw this Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference at android.os.Parcel.readException(Parcel.java:1698) at…
Arya
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Is there a way to save variables(BluetoothGatt objects) in android

I want save BluetoothGatt objects to manage BLE connections in my android app. Currently i am using a static android class to save those variables. But someTimes application vanishes those static variables. public class ConnectedDevicesService { …
Shehan Karunarathne
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Reading heart measurement from Android bluetooth fails with some models

I wrote an Android app to study the variations on heart rate. Wrote the Bluetooth services, callbacks, etc. With the Polar H10 band, everything worked fine. Now trying with the Polar OH1+ and also with another watch, the heart rate was not reaching…
Baltasarq
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How to get notification using BLE, always getting Error

I am trying to get notification from Kotlin on React Native using BLE (Bluetooth Low Energy) connection. Devices are connected each other and I am trying to send notification from Android device to iPhone device. I am using react-native-ble-plx in…
Grigoriy Park
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Is BLE suitable for sending images

I've managed to write a Python program for my Raspberry Pi that interacts with BLE via D-Bus and can register GATT services and store data in chatacteristics that external devices can read. However, my goal is to send images from my Raspberry Pi…
Salivan
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BLE communication data type

Bluetooth newbie here. Is there a best practice among the data type used for BLE communication? In my case I am setting up a ESP32 that acts as Server: it has a single Characteristic with a Notify property, so it repeatedly sends data to all the…
Panda
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Android BLE: onCharactersticChanged not called

I have an issue regarding Android BLE. It is the following: This issue occurs on Samsung Galaxy S10e, Android 10, OneUI 2.5. It comes up when the Smartphone is connected to some Wifi. If the Smartphone is connected to Wifi, onCharacteristic Changed…
Markus
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How to discover android ble services after successful pairing with pin entry?

Inside the BluetoothGattCallback method onConnectionStateChange I am checking for the successful connection with the BLE device and calling the discoverServices method afterwards. The BLE device needs a pin entry (prompt by Android) for an…
DanLand
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onCharacteristicChanged not being hit. Android BLE

I have an app that is using BLE connectivity with my device. Everything works from connecting to the device, discovering the services, writing the characteristic and descriptor. But for some reason, onCharacteristicChanged is not triggering. The…
Jake Levine
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Bluetooth LE Current Battery Percentage

Good day! Cant get battery percentage in percent. Ive successfully connected to GATT services, thed did this: public override void OnServicesDiscovered(BluetoothGatt Gatt, [GeneratedEnum] GattStatus Status) { …
Alexander Man
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Setup password on a Bluez BLE beacon

I am running a BLE beacon in bluez5.52 on a linux machine(ubuntu 14.04) using the default gatt-service and the beacon using the btmgmt provided in the tools folder. Following are the commands I run to setup the beacon: Terminal…
danny
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Does apple read the BLE device before they share the data with BLE devices?

Does apple read the BLE device before they share/advertise the data with BLE devices? I am asking this question because I tried to connect the android device via Bluetooth to the iPhone. I am able to connect successfully but when I tried to…
Harsh Shah
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