Does anyone know how to make an HC-05 Bluetooth module automatically connect to an android device when in range? I know how to enter AT command mode, but I do not know how to set up auto connect. Here is a link to a website that has helped me enter into AT command mode on the HC-05. HC-05 FC-114 and HC-06 FC-114. First Look | Martyn Currey
I think you need the app to repeatedly attempt to connect with the Bluetooth module.
I plan to revisit this in a few days and I'll post an example of how I think you'd do it.
I haven't used App Inventor 2 for a while but I think a timer set to attempt a connection every few seconds would work.
You'll want to save the Bluetooth's ID to string so the app knows which device to attempt connecting.
If these suggestions aren't enough to figure out how to do this, I'll go into more detail in near future (assuming I'm correct about how to do this).