Bluetooth Communication

The inhaler/pin and the app will be connected through Bluetooth Low-Energy.

The Inhaler and the Pin are Gatt servers. The Android app is a Gatt Client. The interface between the inhaler/pin and the app are Gatt Services/Characteristics which we need to agree on.

Inhaler-app connection

Ideally, the inhaler will initiate the BLE connection from itself to the app. Once the BLE connection is established, then the inhaler will indicate an IUE to the app. If the inhaler receives an acknowledgement from the app that the indication was transmitted successfully, the inhaler will continue sending IUEs to the app until all IUEs are sent and deleted.

notes:

• Can the inhaler initiate a BLE connection? (probably yes)
• But how does the inhaler know which phone to connect to?
• What did ST mean when they said the MCU can retain connections during standby mode? Ideally, we want to terminate the connection.
• Assuming the inhaler can initiate a BLE connection, can the app accept this connection?
• How will the app know it is connected to an inhaler?
• Will the app be able to receive the indications even though there is a delay in Android between establishing the BLE connection and establishing the GATT connection?
• We need to design a GATT interface so the Android app and the inhaler can communicate.

Pin-app connection

The app should initiate the BLE connection. Once the app and the pin are connected, the pin will be a passive server which waits for read requests. The app will make read requests as necessary.