Without an app on the iPhone, the best solution might be to use HID as you say. Just turn it into a keyboard and when you get the NRF.connect or disconnect events you can see when the iPhone thought it was in range enough to try and connect.
It might work - otherwise you'd need an app I'm afraid... Or you might be able to do something by turning the Puck into an iBeacon?
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Without an app on the iPhone, the best solution might be to use HID as you say. Just turn it into a keyboard and when you get the
NRF.connect
ordisconnect
events you can see when the iPhone thought it was in range enough to try and connect.It might work - otherwise you'd need an app I'm afraid... Or you might be able to do something by turning the Puck into an iBeacon?