txt: ## dist_zef-patrickb-RPi-ButtonWatcher.md
  # 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:
  
  * pins
  
  A list of WiringPi pin numbers to watch.
  
  * edge
  
  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.
  
  * debounce
  
  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:
  
  * pin
  
  The WiringPi pin number that was triggered.
  
  * edge
  
  Either `Edge.RISING` or `Edge.FALLING`.
  