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
I just had the same problem. If you see the source code of BluetoothGatt.java you can see that there is a method called refresh() /** * Clears the internal cache and forces a refresh of the services from the * remote device. * @hide */ public boolean refresh() { if (DBG) Log.d(TAG, “refresh() – device: … Read more
No, this is not a bug. This issue was brought up to Google where they responded saying that this was the intended behavior and they won’t fix it. They directed developers to this site where it points out that location permission is now needed for hardware identifier access. It is now the developer’s responsibility to … Read more
Try this… Run gatttool -b <MAC Address> –interactive like you did before. You’ll get a prompt and then you type connect. You should see a CON in the prompt indicating that you’ve connected to the device. Then type char-read-uuid 2902. You should get a list of all CCC (Client Characteristic Configuration) attributes on the device. … Read more
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
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 send less than 160 characters (160 bytes). p/s : Let edit following as you want. Do not follow … Read more
Important implementation hints (Perhaps some of those hints aren’t necessary anymore due to Android OS updates.) Some devices like Nexus 4 with Android 4.3 take 45+ seconds to connect using an existing gatt instance. Work around: Always close gatt instances on disconnect and create a fresh instance of gatt on each connect. Don’t forget to … Read more
The distance estimate provided by iOS is based on the ratio of the beacon signal strength (rssi) over the calibrated transmitter power (txPower). The txPower is the known measured signal strength in rssi at 1 meter away. Each beacon must be calibrated with this txPower value to allow accurate distance estimates. While the distance estimates … Read more
For an iBeacon with ProximityUUID E2C56DB5-DFFB-48D2-B060-D0F5A71096E0, major 0, minor 0, and calibrated Tx Power of -59 RSSI, the transmitted BLE advertisement packet looks like this: d6 be 89 8e 40 24 05 a2 17 6e 3d 71 02 01 1a 1a ff 4c 00 02 15 e2 c5 6d b5 df fb 48 d2 b0 … Read more