Making android bluetooth app send a warning when out of range

I have a quick question about trying to develop a new app on Android. So as the title says, I'm to use Bluetooth to link up two Bluetooth capable devices and when they are at a specific maximum range (5-20 ft), have the phone play some sort of alarm.

I do not however, own an Android Phone, but I am instead developing it on the Emulator on my computer. Earlier, I discovered that the emu is not Bluetooth capable nor does it have any form of sounds.

Is there a开发者_运维知识库ny way of continuing on besides getting a real phone? Any helpful workarounds are welcome

regarding the emulator capabilities : you'd better buy a device soon ... duplicate?

And regarding the alarm triggering i'm a bit curious : on what are you relying ? SNR ? is there an easy way to access this kind of data on Android ? (only had a glance at the reference pages)