[Microbit-Python] While loop without sleep

[Nicholas H.Tollervey]

On 19/01/17 18:14, Matt Hickford wrote:
> Hi. My program reacts to button presses. The documentation gives an
> example of while loop that checks if the button has been pressed,
> reacts, then sleeps between loops
> https://microbit-micropython.readthedocs.io/en/latest/button.html#example
> 
>     while True:
>          sleep(100)
>          if button_a.was_pressed():
>                act()
>      
> Does it matter if I omit the sleep statement? I wrote
> 
>     while True:
>         if button_a.was_pressed():
>                act()
> 
> It seems to work. My only concern was, might it drain the battery
> because it's looping very fast? Any thoughts?
> -Matt
> 
> 
> _______________________________________________
> Microbit mailing list
> Microbit at python.org
> https://mail.python.org/mailman/listinfo/microbit
> 

The sleep is to debounce the button.

Say your act() function should only be called once per-press of the
button then if the loop is faster than it takes a human to push the
button down and then release it (and, believe me, it is) then you'll get
a number of calls to act() over the duration of the single push/release
interaction. By adding a shortish sleep you avoid this problem.

Does this make sense? More than happy to answer questions.

N.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 455 bytes
Desc: OpenPGP digital signature
URL: <http://mail.python.org/pipermail/microbit/attachments/20170119/67ea04c8/attachment.sig>