I am working on Android BLE as a peripheral connected to a custom device that runs Nordic NRF51 as a central. The project requires Android peripheral to connect to two NRF51 central devices.
Android is advertising two different Advertisement UUIDs one for left and other for right Nordic NRF51 devices. Ideally, I would like to have both Nordic Centrals to connect to the Android at the same time.
I have two main issues.
First issue. Android can get both connections fine. The problem occurs when Android sending notification or Android sending reply back as result of Write Request from the central. When both Centrals are connected, often notification nor the send reply works. I confirmed that the Nordic central does not receive the notification nor the reply. Does anyone have experiences in Android as a Peripheral supporting multiple connections at the same time? I have tried two BluetoothGattServer instances (one for each device) as well as one instance of BluetoothGattServer and based on the connected device, I can tell which Central the event if for and handle it correctly. It is sending notification or send reply to Write Request that at times it does not get sent from Android. I am using synchronized methods on the GattServerCallback event handlers.
Second Issue. Due to the first issue, I am now only advertising one UUID at a time. The idea is to switch between two advertising UUIDs, thus have only one connection at time. The problem now is switch advertising. About 1 out 3 times, when I start advertising with first UUID with its name (LFDroid), it appears that it is actually advertising second UUID with its name (RTDroid) briefly (1 or 2 seonds) and then advertises what was requested. Note that second UUID advertising was stopped on previous switching. It almost looks like when I ask to advertise, it starts to advertise with the last advertised UUID and name and then quickly advertises what is requested. This now causes problem because both Nordic Centrals sees the advertisement and connects.
Any suggestions would be appreciated.
