Android BluetoothGatt - status 133 - register callback

Android OS < 6.0：

mBluetoothDevice.connectGatt(context, false, callback);

Android OS >= 6.0：

mBluetoothDevice.connectGatt(context, false, callback, BluetoothDevice.TRANSPORT_LE);

Ultimately, hardware equipment is needed to completely solve this problem.

Alright I have figured it out. The issue was mainly an oversight of when I was reading through the BluetoothGatt documentation. I was calling .disconnect(), but not .close(). Since the Galaxy s4 can only handle 6 connections at a time, my service was only running 6 times. Adding the .close() to my code allowed it to properly shut down the connection and freed up those used connections.

Source that made me re-read the docs more carefully!

So remember to use .close() on your BluetoothGatt object if you have a recurring connection to the same device(s)!!

• On some devices, it got fixed with mBluetoothDevice.connectGatt(context, false, callback, BluetoothDevice.TRANSPORT_LE);

• on some devices like Samsung S7, A8, it was a problem with the ScanSettings.Builder().setReportDelay(400) // or 500ms. it should not be 0 or more like 1000ms. ScanSettings settings = new ScanSettings.Builder() .setScanMode(ScanSettings.SCAN_MODE_BALANCED) .setReportDelay(400) .build();

After months of research and pulling my hair out, I have found a solution that is not normally talked about.

Your normal connect request looks something like this:

cGatt.connectGatt(this, false, gattCallback);

There is another version of the connectGatt command, with a 4th parameter. This parameter specifies what type of bluetooth device you are connecting to. I added a "2" to specify that I am connecting via Bluetooth LE. (it's called "transport", forgive me if my explanation is incorrect, but it solved all my problems)

Try this:

cGatt.connectGatt(this, false, gattCallback, 2);

And BAM, now my #133 nightmare is over (I pray)!