Ubuntu DigitalInputDevice .when_activated not firing

[KevWal]

Hi

I am running Ubuntu 20.04.6 64bit on a Pi 3 for ROS.

Tried using the OS packages python3-gpiozero (1.4.1-1.2) with python3-rpi.gpio (0.6.5-1ubuntu3) and rpi.gpio-common:arm64 (0.6.5-1ubuntu3) and also the pip3 packages gpiozero-1.6.2-py2.py3-none-any.whl and RPi.GPIO-0.7.1.tar.gz but with the same result.

The 'Button' device works, but the DigitalInputDevice .when_activated doesn't seem to get called.

Example output:

23 was pressed!
23 was released!
24 was pressed!
24 was released!
Init
Init
e1 0 e2 0
e1 0 e2 0
e1 0 e2 0
e1 0 e2 0
e1 0 e2 0
e1 0 e2 0

Code:

#!/usr/bin/python3

from gpiozero import DigitalInputDevice
from time import sleep

from gpiozero import Button

SAMPLETIME = 2

class Encoder(object):
    def __init__(self, pin):
        self._value = 0
        encoder = DigitalInputDevice(pin, pull_up=True)
        encoder.when_activated = self._increment
        encoder.when_deactivated = self._increment
        print("Init")

    def reset(self):
        self._value = 0

    def _increment(self):
        self._value += 1
        print("Inc")

    @property
    def value(self):
        return self._value


button = Button(23, pull_up=True)
button.wait_for_press()
print("23 was pressed!")
button.wait_for_release()
print("23 was released!")
button.close()

button = Button(24, pull_up=True)
button.wait_for_press()
print("24 was pressed!")
button.wait_for_release()
print("24 was released!")
button.close()

e1 = Encoder(23)
e2 = Encoder(24)

while True:
    print("e1 {} e2 {}".format(e1.value, e2.value))
    sleep(SAMPLETIME)

Thanks very much!
Kevin

[lurch]

    def __init__(self, pin):
        self._value = 0
        encoder = DigitalInputDevice(pin, pull_up=True)
        encoder.when_activated = self._increment
        encoder.when_deactivated = self._increment
        print("Init")

In the function above, encoder is a local variable, and so I think it will go out of scope (and get garbage-collected) at the end of the function. Does your code work any better if you do self._encoder = ... instead?

[KevWal]

Thank you, sorted, working now :)