wire up the buttons with property table

lib/trilobot/application.ex

@@ -32,7 +32,9 @@ defmodule Trilobot.Application do
 
   def children(_target) do
     [
-      {Trilobot.Buttons, nil}
+      {PropertyTable, name: Trilobot.ButtonTable},
+      {Trilobot.Buttons, nil},
+      {Trilobot.RGB, nil}
     ]
   end
 

lib/trilobot/buttons.ex

@@ -2,6 +2,8 @@ defmodule Trilobot.Buttons do
   use GenServer
   alias Circuits.GPIO
 
+  @table Trilobot.ButtonTable
+
   @a_button_pin 5
   @b_button_pin 6
   @x_button_pin 16
@@ -19,10 +21,10 @@ defmodule Trilobot.Buttons do
   }
 
   @button_pins_to_button_names %{
-    @a_button_pin => :a,
-    @b_button_pin => :b,
-    @x_button_pin => :x,
-    @y_button_pin => :y
+    @a_button_pin => "a",
+    @b_button_pin => "b",
+    @x_button_pin => "x",
+    @y_button_pin => "y"
   }
 
   def start_link(nil) do
@@ -44,6 +46,11 @@ defmodule Trilobot.Buttons do
     {:ok, x_led} = GPIO.open(@x_led_pin, :output, initial_value: 0)
     {:ok, y_led} = GPIO.open(@y_led_pin, :output, initial_value: 0)
 
+    PropertyTable.put(@table, ["button", "a"], :released)
+    PropertyTable.put(@table, ["button", "b"], :released)
+    PropertyTable.put(@table, ["button", "c"], :released)
+    PropertyTable.put(@table, ["button", "d"], :released)
+
     state = %{
       a_button: a_button,
       a_led: a_led,
@@ -77,8 +84,9 @@ defmodule Trilobot.Buttons do
 
   defp log_pin_change(pin, value) do
     require Logger
-    pin = Map.get(@button_pins_to_button_names, pin)
+    name = Map.get(@button_pins_to_button_names, pin)
     event = if value == 0, do: :pressed, else: :released
-    Logger.info("pin #{pin} #{event}")
+    Logger.info("pin #{pin} => #{name} #{event}")
+    PropertyTable.put(@table, ["button", name], event)
   end
 end

lib/trilobot/rgb.ex

@@ -0,0 +1,32 @@
+defmodule Trilobot.RGB do
+  use GenServer
+
+  def start_link(nil) do
+    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
+  end
+
+  def init(nil) do
+    PropertyTable.subscribe(Trilobot.ButtonTable, ["button", "a"])
+    {:ok, i2c} = Circuits.I2C.open("i2c-1")
+    :ok = SN3218.RgbLeds.enable(i2c)
+    {:ok, %{i2c: i2c}}
+  end
+
+  def handle_info(%PropertyTable.Event{value: :pressed}, state) do
+    :ok = SN3218.RgbLeds.set_leds(state.i2c, List.duplicate({127, 255, 127}, 6))
+
+    {:noreply, state}
+  end
+
+  def handle_info(%PropertyTable.Event{value: :released}, state) do
+    :ok = SN3218.RgbLeds.set_leds(state.i2c, List.duplicate({0, 0, 0}, 6))
+
+    {:noreply, state}
+  end
+
+  def handle_info(message, state) do
+    require Logger
+    Logger.error("#{__MODULE__} received an unexpected message: #{inspect(message)}")
+    {:noreply, state}
+  end
+end

mix.exs

@@ -72,7 +72,8 @@ defmodule Trilobot.MixProject do
       {:nerves_system_mangopi_mq_pro, "~> 0.4", runtime: false, targets: :mangopi_mq_pro},
       {:circuits_gpio, "~> 1.1"},
       {:circuits_i2c, "~> 2.0"},
-      {:pigpiox, "~> 0.1.2"}
+      {:pigpiox, "~> 0.1.2"},
+      {:property_table, "~> 0.2"}
     ]
   end