So the spring with a magnet inside of it acts a bit like an electromagnet. Since the spring has less weight, it moves and not the magnet, creating a tone with the PWM.
EDIT: 23:11 eastern time.
The “floating” spring in the tail cap can vibrate against the bottom of the cap too as it is not soldered in place but simply pinched in by its shape. The right bend would have a section of that spring just a fraction of a millimetre away from the bottom of the tail cap and would make it very noisy if the PWM made the spring move.
Yes, it's the spring above the magnet; the PWM'd (2kHz, because it had to be software PWM) current through it in the magnetic field causes an oscillating Lorentz force on the spring and thus vibration. I can silence it by removing the magnet, but I don't want to sacrifice it's benefits.
So here are the riddled instructions for the easter-egg mode:
While it shows what's left, tap the left hand's digits, activate the darkest mode, tap the digits in your belly, then the right hand's digits, ta-ta-ta-taaaa!
Hihi, this feels a bit like those adventure movies where riddles must be solved to find a treasure... This easter-egg mode has been a secret for years (well, two years...) :)
“While it shows what’s left” probably refers to battery check mode.
A simple meaning for “tap the left hand’s digits” can be deduced by counting your fingers. That should mean either four or five taps, depending whether the thumb counts.
I am not sure what “tap the digits in your belly” means. Could that mean zero, since there are no digits in your belly. Is that a simple pause?
Once again, “right-hand digits” might mean four or five taps.
I will never know whether any of this is right, since I do not have a flashlight to test it on!
While it shows what’s left, <— while in batt check
tap the left hand’s digits, <—- tap 5 times
activate the darkest mode, <—-turn the light off
tap the digits in your belly, <—- |button| and turn it on!
then the right hand’s digits, <—- tap 5 times!!!
ta-ta-ta-taaaa!
