bluetooth-lowenergy | 易学教程

Trying to retrieve previously paired bluetooth device in IOS app will not respond with failure if device is off

阅读更多关于 Trying to retrieve previously paired bluetooth device in IOS app will not respond with failure if device is off

问题 Sorry for the long title, but we are having a pretty interesting issue with using corebluetooth for ios. We are issuing a call to retrievePeripherals in CBCentralManager and are able to find the previously paired device. This happens though regardless if the device is on or off though. I can't find anything in apple's documentation as to why it's able to find the device when it is off though and it isn't showing up in Settings -> Bluetooth -> Devices. I'm suspecting that Apple is caching this

Is it possible (and does it make sense) to have a bluetooth iOT device in peripheral mode listening to both, BLE and Bluetooth Classic connections

阅读更多关于 Is it possible (and does it make sense) to have a bluetooth iOT device in peripheral mode listening to both, BLE and Bluetooth Classic connections

We are currently building a device that needs to be compatible with newer smartphones that run BLE but also be backwards compatible with Bluetooth 2.1. We are using a Mediatek Linkit ONE board for our prototype which can operate in dual mode. They have Bluetooth classes available, however it seems that I would have to pick between either running 1) Bluetooth Classic 2.1 OR 2) BLE The classes and docs are here: http://labs.mediatek.com/site/znch/developer_tools/mediatek_linkit/api_references/Lib_Bluetooth.gsp We basically want to make our device compatible with as many Smart phones as possible

Android BLE characteristics getValue returns null

阅读更多关于 Android BLE characteristics getValue returns null

问题 I am trying to write text data to my BLE device. So , i am following Android Bluetooth GATT classes to do the task. But i found writing the text to the Characteristics is fine but while trying to retrieve the Characteristics value , it returns null. MyCode : public void writeCharacteristic(BluetoothGattCharacteristic characteristic, String text) { String TAGS ="MyBeacon"; if (mBluetoothAdapter == null || mBluetoothGatt == null) { Log.w(TAGS, "BluetoothAdapter not initialized"); return; } else

Scanning for BLE devices on Android 8+ in the background

阅读更多关于 Scanning for BLE devices on Android 8+ in the background

I'm using the following method from BLE scanner API on Android 8+ to scan for BLE Beacons startScan(List<ScanFilter> filters, ScanSettings settings, PendingIntent callbackIntent) The problem is that after sometimes I can see Scan Logs but nothing is delivered by the callbackIntent any idea why is this happening? This is the expected behavior on Android 8+. if you need to scan continuously a periodic mechanism is needed in this case. For more information about scanning on different Android versions and different ways. Have a look here 来源： https://stackoverflow.com/questions/52777982/scanning

BluetoothGatt.writeCharacteristic() always returns false.

阅读更多关于 BluetoothGatt.writeCharacteristic() always returns false.

问题 I am writing an Android app to talk with an Arduino using BLE. I have been able to scan devices, connect to the target, discover services, get characteristics, and read those that are readable. However, when I try to write a writeable characteristics, the method always returns false. When I debugged into the android.bluetooth code, the following sequence occurs: characteristic.getService().getDevice always returns null, which causes the writeCharacteristic to fail. Any help is greatly

Bluetooth Low-Enery on Linux API

阅读更多关于 Bluetooth Low-Enery on Linux API

问题 I have a device with a few custom GATT services, and I would like to write a Linux program to interact with it. After some searching I found out that Linux is using BlueZ to handle the Bluetooth LE protocol. I'm using Ubuntu 15.10 with BlueZ 5.35, but I cannot figure out how use this BlueZ from a user-space program. I cannot find an API documentation anywhere, no tutorials, examples, nothing. Is it even possible to use this BlueZ stack to do anything other than just connecting to Bluetooth

How do you get data from a Bluetooth LE device

阅读更多关于 How do you get data from a Bluetooth LE device

问题 I have a bluetooth barcode scanner that supports bluetooth LE and I am trying to get the barcode information from it when one is scanned. I can connect to it fine onServicesDiscovered gets called in my BluetoothGattCallback but I am not sure what to do from there. With a classic bluetooth connection you would get a InputStream from a BluetoothSocket and you would just wait for the read() to give you data but I am not sure how it works with Bluetooth LE. I tried looping through the

Node.js - how to set environment variables in code

阅读更多关于 Node.js - how to set environment variables in code

问题 I am fairly new to node.js, and have a program that I have to set an environment variable in order to run (using the noble library, my bash command is: sudo NOBLE_HCI_DEVICE_ID=x node program.js , to tell my code which Bluetooth adapter - HCI device - to use). The reason behind this is that I have a number of modules, each needing their own Bluetooth adapter, and I wish to specify in my code which adapter each module should use. I've found lots of articles telling me how to consume

Bluetooth Low Energy device scanning Failed with an exception

阅读更多关于 Bluetooth Low Energy device scanning Failed with an exception

问题 I am referring to developer docs to scan BLE devices - http://developer.android.com/guide/topics/connectivity/bluetooth-le.html In my activity class LookUpActivity , I called a method findBLE() on a button click- //This will scan BLE devices public void findBLE() { Intent intent = new Intent(LookUpActivity.this, DeviceScanActivity.class); startActivity(intent); } But got the following exception - Could not find class 'com.testapp.main.DeviceScanActivity$1', referenced from method com.testapp

Windows does not answer BLE parameter update request

阅读更多关于 Windows does not answer BLE parameter update request

问题 I have a custom embedded device with a Bluetooth low energy stack. The device is advertising itself until a connection is requested, I pair and connect to it via the Bluetooth menu in Windows 10, I can read/write to my custom GATT services using the following BLE GATT functions from the Win32 API. For my application I need to receive high frequency data using notifications on a characteristic so I enable it using the same API as stated above and receive the correct data but too slow. The