Puck sensing the battery ?

[espruino-discuss]

Posted at 2016-09-27 by tochinet

The Puck.js looks a very promising platform. Will it be able to sense its battery level, in order to plan in advance the replacement ? (Like an Arduino can sense its Vcc using the internal analog reference)

[gfwilliams]

Posted at 2016-09-27 by @gfwilliams

Yes, absolutely - and there's a standard BLE characteristic for reporting it too.

CR2032s have quite a good discharge curve (pretty steady for 90% of capacity, then drops off suddenly for final 10%), so it's pretty easy to tell from the voltage when they need replacing.

[espruino-discuss]

Posted at 2016-10-04 by Litch

So therefore, please correct if i am wrong, you could set a value (based on the current voltage) of say 10% battery life, and when then hits you could have the ability to send a message or alert via BLE, to an app or phone that the battery needs replacing?

[gfwilliams]

Posted at 2016-10-04 by @gfwilliams

Yes - in fact there's a way of reporting battery state along with the 'I'm here' message the Puck would send out anyway.

Generally phones won't just send an alert because of a BLE device (because it could be abused) but you could switch to advertising via Eddystone, or your app could detect the low battery state and issue an alert.