I struggled with the same issue. To fix it you have to enable “Location” (GPS) in the settings of the phone as well as request location permission in the app at runtime. Both need to be done for scanning to work properly. To request the location permission put the following in a dialog or the … Read more
Using the class UUID An example like this: UUID.randomUUID().toString()
This functionality has all been moved to the open source Android Beacon Library which will: wake up/launch your app when iBeacons matching a desired pattern are detected perform beacon scanning in the background even if the user has not launched your app yet reduce the scan rate automatically in the background to 30 seconds every … Read more
I finally figured this problem out. The device I am using is a Samsung Galaxy S4 and the actual problem (thanks Wibble for guidance in your answer, but you are slightly off in your conclusion) appears to be a threading issue. In Wibble’s answer, he stated that adding a button to connect fixed his issue. … Read more
You have to wait until the [-CBCentralManagerDelegate centralManagerDidUpdateState:] callback has been called. And then, verify that the state is PoweredOn before you start scanning for peripherals.
That happens often really often to me. I’m developing with it and it just happens from time to time. I was also able to reproduce your error within 5 minutes 😉 I’m running bluez v.5.17. However i can run lescan more than one time without this error. hcitool lescan Set scan parameters failed: Input/output error … Read more
With your Bluetooth dongle plugged in, running the following command will tell you the device name and give its state: $ hciconfig The output should look something like this: hci0: Type: BR/EDR Bus: USB BD Address: 00:01:02:aa:bb:cc ACL MTU: 1021:8 SCO MTU: 64:1 DOWN RX bytes:1000 acl:0 sco:0 events:47 errors:0 TX bytes:1072 acl:0 sco:0 commands:47 … Read more
CBPeripheral’s identifier property will serve your purpose, available from a still-unconnected device in CBCentralManager’s didDiscoverPeripheral delegate method: – (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI CBPeripheral *peripheral … NSUUID* serverId = [peripheral identifier]; I have a half dozen LE devices I’m experimenting with, including multiple sets of identical devices. I just confirmed that across … Read more
With disconnect() you can later call connect() and continue with that cycle. Once you call close() you are done. If you want to connect again you will have to call connectGatt() on the BluetoothDevice again; close() will release any resources held by BluetoothGatt.
UPDATE : Please see more answer to know there is other way to achive your expect. At 2014, BLE allows you transfer maximum of 20 bytes. If you want to send more than 20 bytes, you should define array byte[] to contain how many packets you want. Following example worked fine if you want to … Read more