NAME
RPi::ButtonWatcher - A button push event supplier
SYNOPSIS
use RPi::Wiring::Pi;
use RPi::ButtonWatcher;
die if wiringPiSetup() != 0;
# Takes WiringPi pin numbers.
my $watcher = RPi::ButtonWatcher.new(pins => ( 4, 5, 6 ), edge => BOTH, PUD => PULL_UP);
$watcher.getSupply.tap( -> %v {
my $e = %v<edge> == Edge.RISING ?? 'up' !! 'down';
say "Pin: %v<pin>, Edge: $e";
});
DESCRIPTION
This library provides a supplier of GPIO pin state changes.
Read/write access to /sys/class/gpio/export and /sys/class/gpio/gpioXX/ is required for this library to work. This usually means the user running the code has to be in the gpio group.
This module uses polling to detect state changes. A polling interval of 0.1 seconds is usually fast enough for normal button pushes.
The Sysfs interface is documented here: https://www.kernel.org/doc/Documentation/gpio/sysfs.txt
METHODS
new
Do initialize WiringPi before using this class using wiringPiSetup!
Takes the following parameters:
A list of WiringPi pin numbers to watch.
The edges to listen for.
* `Edge.RISING`
Triggered when a button is released.
* `Edge.FALLING`
Triggered when a button is pressed.
* `Edge.BOTH`
Triggered on both, button presses and releases.
Time in seconds to sleep between polls. Faster means more responsive, but also more system resource eating. Defaults to 0.1 (100ms).
getSupply
Returns a supply that can be tapped. The supply will emit hashes with two entries:
The WiringPi pin number that was triggered.
Either Edge.RISING or Edge.FALLING.