How to let user know that an automatic process in a mobile app can still be triggered from a different screen?

Question

I'm working on a mobile app with Bluetooth Low Energy, that can trigger some hardware by either holding the phone near it (primary action) or trigger the hardware manually by looking for nearby devices and showing them in a list (secondary action).

My 2 screens basically looks like this:

The main tab (Scan) is a simple animation showing the user to hold his phone near the device to trigger it. It will show another animation if it detects a device nearby a phone and sends a signal to trigger it.

The secondary tab (Manual) will show all nearby hardware that can be triggered manually (if applicable). The user can click on the circle to trigger the device.

Now, even if the user is in the "manual" subtab, he can still trigger a device by holding his phone next to the hardware device. But it might look that the user HAS to be in the "SCAN" tab for that to work. This might lead to a case where the user accidentally triggers because he thought that it would not work.

How do i make clear that the SCAN is still active, even if in the other tab. By extension, the trigger can even work if the user is in the application settings, or has the app running in the background.

Answer 1

Maybe just tell them? For example:

Answer 2

Using the same animation from the main tab (Scan) in the secondary tab (Manual) could make clear that the SCAN is still active. It can be smaller to make place for the list of nearby hardware. I've seen something similar in Android with Google Pay NFC using a small animation in different tabs.

Renaming the secondary tab to "Scan and manual" could also be an option, but it's probably too long.

Maybe even using only one tab with Scan and Manual functionalities would make clear that the scan is always active, or putting the manual functionality under the Setting tab, but I like the 3 tabs design (Scan, Manual, Setting).

A different approach would be to place the Scan tab in the middle (where Manual tab is now) so it communicates the idea that the scan is always ready if the phone is near the device.