Use delux in blinky

[mnishiguchi]

Replace nerves_leds with delux in the blinky example.

Do we still need the hello_leds example as well?

[mnishiguchi]

As I quickly compare blinky and hello_leds, only remarkable difference is how blinking loop is implemented in the top-level module:

• blinky - loop and intervals are managed by our code
• hello_leds - loop and intervals are managed by Nerves.Leds

Other than that, they look nearly identical to me.

❯ diff -u blinky/lib/blinky.ex  hello_leds/lib/hello_leds.ex

--- blinky/lib/blinky.ex	2022-08-16 19:56:22.000000000 -0400
+++ hello_leds/lib/hello_leds.ex	2022-08-16 19:58:29.000000000 -0400
@@ -1,9 +1,9 @@
-defmodule Blinky do
+defmodule HelloLeds do
   @moduledoc """
   Simple example to blink a list of LEDs forever.

-  The list of LEDs is platform-dependent, and defined in the config directory
-  (see config.exs). See README.md for build instructions.
+  The list of LEDs is platform-dependent, and defined in the config
+  directory (see config.exs).   See README.md for build instructions.
   """

   # Durations are in milliseconds
@@ -14,24 +14,30 @@
   require Logger

   def start(_type, _args) do
-    led_list = Application.get_env(:blinky, :led_list)
+    led_list = Application.get_env(:hello_leds, :led_list)
     Logger.debug("list of leds to blink is #{inspect(led_list)}")
-    spawn(fn -> blink_list_forever(led_list) end)
+    Enum.each(led_list, &start_blink(&1))
     {:ok, self()}
   end

-  # call blink_led on each led in the list sequence, repeating forever
-  defp blink_list_forever(led_list) do
-    Enum.each(led_list, &blink(&1))
-    blink_list_forever(led_list)
-  end
-
-  # given an led key, turn it on for @on_duration then back off
-  defp blink(led_key) do
-    # Logger.debug "blinking led #{inspect led_key}"
-    Leds.set([{led_key, true}])
-    :timer.sleep(@on_duration)
-    Leds.set([{led_key, false}])
-    :timer.sleep(@off_duration)
+  # Set led `led_key` to the state defined below. It is also possible
+  # to globally define states in `config/config.exs` by passing a list
+  # of states with the `:states` keyword.
+  #
+  # The first parameter must be an atom.
+  @spec start_blink(Keyword.T) :: true
+  defp start_blink(led_key) do
+    Logger.debug("blinking led #{inspect(led_key)}")
+    # led_key is a variable that contains an atom
+    Leds.set([
+      {
+        led_key,
+        [
+          trigger: "timer",
+          delay_off: @off_duration,
+          delay_on: @on_duration
+        ]
+      }
+    ])
   end
 end

Probably we no longer need hello_leds.

Once we know we keep only one of them, the name of this example can be either blinky or hello_leds.

[fhunleth]

Looks great! I squashed some commits together and merged!