Class and example for simple AS312 PIR motion sensor

HARDWARE.md

@@ -202,7 +202,7 @@ Polling and reading follow a call and response pattern.
 | :--------------- | :------:       | :--------    | :---------------   |------ |
 | BH1750           | :heart:        | Digital In   | `Sensor::BH1750`   | Ambient Light
 | HC-SR501         | :yellow_heart: | Digital In   | `DigitalIO::Input` | PIR. Needs class: `Sensor::HC-SR501`
-| AS312            | :heart:        | I2C          | `Sensor::AS312`    | PIR
+| AS312            | :green_heart:  | I2C          | `Sensor::AS312`    | PIR (based on `DigitalIO::Input`)
 | TCS34725         | :heart:        | I2C          | `Sensor::TCS34725` | RGB
 | APDS9960         | :heart:        | I2C          | `Sensor::APDS9960` | Proximity, RGB, Gesture
 

examples/sensor/as312.rb

@@ -0,0 +1,16 @@
+#
+# Example using AS312 PIR motion sensor.
+#
+require 'bundler/setup'
+require 'denko'
+
+board = Denko::Board.new(Denko::Connection::Serial.new)
+sensor = Denko::Sensor::AS312.new(board: board, pin: 8)
+
+sensor.on_motion_start { print "Motion detected!     \r" }
+sensor.on_motion_stop  { print "No motion detected...\r" }
+
+# Trigger an initial read.
+sensor.read
+
+sleep

lib/denko/sensor.rb

@@ -14,5 +14,6 @@ module Sensor
     autoload :SHT3X,       "#{__dir__}/sensor/sht3x"
     autoload :QMP6988,     "#{__dir__}/sensor/qmp6988"
     autoload :RCWL9620,    "#{__dir__}/sensor/rcwl9620"
+    autoload :AS312,       "#{__dir__}/sensor/as312"
   end
 end

lib/denko/sensor/as312.rb

@@ -0,0 +1,8 @@
+module Denko
+  module Sensor
+    class AS312 < DigitalIO::Input
+      alias :on_motion_stop  :on_low
+      alias :on_motion_start :on_high
+    end
+  end
+end