Can anyone give me an idea of how a bluetooth device like silent beacon can send a command to the phone while the screen is closed

Question

I am talking the silentbeacon.com personal safety alarm device. How is it able to connect with the phone with bluetooth while the screen is locked. I am looking for an IOS solution.

Answer 1

Just because the screen is locked on the iOS device doesn't mean it cannot do any Bluetooth functionality. iOS devices have a special background mode that allows them to continuously read BLE adverts and also communicate with remote BLE devices. You can find more about this here:-

• CoreBluetooth background processing for iOS apps
• BLE device keeps connecting with iPhone when app terminates
• iOS - BLE scan and connect to peripheral in background