How to debounce the USR switch?

[on4aa]

I currently have this tiny bit of code on a Pyboard v1.1:

Code: Select all

import pyb

def toggle_led():
    ​​pyb.LED(3).toggle()

pyb.Switch().callback(toggle_led)

However, this set-up is susceptible to contact bounce.
I tried adding a pyb.delay(500) to no avail.
Is there some elegant way to remedy switch bounce on the Pyboard?

PS: There are also points to be gained over on https://stackoverflow.com/q/47479907/2192488

[on4aa]

I came up with below solution, which for all intends and purposes works fine for me.
However, there is a far more intelligent (and involved) solution posted elsewhere on this forum.

Code: Select all

import pyb

def toggle_led():
    pyb.disable_irq()
    pyb.delay(100)
    if sw.value(): pyb.LED(3).toggle()
    pyb.enable_irq()

sw = pyb.Switch()
sw.callback(toggle_led)

[on4aa]

There is a much better way without a need for interrupts.

Here is a link to the buttons example in Peter Hinch's excellent uasyncio tutorial.