Safe distance device RF or BLE or other?

[paulteo84]

Hi,

i'm thinking build a safe distance device for school kids. Is a small device like a pet tracker which powered by CR2302 batt.
How will the device will work, boy "A" has a device and boy "B" has a device too. If they are happen to be near each other of a radius of <1.2m, both device will sound out beep.

Need advise

to use RF or BLE?
require coding?

Much appreciate your feedback!!

 

[srizbf]

Some not exact comparison:

RF Based:
Each device should have a transmitter and a receiver.

BLE Based:
Each will have a BLE module of transmitter and Reciever.

BLE require coding.

BUt running with CR2032 may not be possible.(definitely not in BLE)

distance requirement may not be met strictly as each will have
their range beyond the required one.
so it will detect beep beyond the minimum distance.