Merge pull request #8 from UncleGrumpy/elixir_ledc

Add LEDC example for Elixir

elixir/LEDC_Example/.gitignore

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+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where third-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+ledc_example-*.tar
+
+# Temporary files, for example, from tests.
+/tmp/
+
+# Ignore compiled amv gilers.
+*.avm
+
+# Ignore formatter files.
+/.formatter.exs

elixir/LEDC_Example/README.md

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+# `LEDC_Example` Application
+
+Welcome to the `LEDC_Example` AtomVM application.
+
+The `LEDC_Example` AtomVM application illustrates use of the AtomVM `LEDC` interface.
+
+LEDs are wired to GPIO pins 4, 5, 18, and 19 and should use a resistor (minimum 100 Ohm up to 1K, 220 Ohm is a good choice). Change the number 
+for the GPIO pins in the example if necessary. See the Blinky example for wiring if you are unsure.
+
+For more information about programming on the AtomVM platform, see the [AtomVM Programmers Guide](https://doc.atomvm.net/programmers-guide.html).
+
+## Supported Platforms
+
+| Platform | Supported |
+|----------|-----------|
+| `esp32`  | ✅ |
+| `stm32`  | ❌ |
+| `generic_unix`  | ❌ |
+
+For general information about building and executing Erlang AtomVM example programs, see the Erlang example program [README](../README.md).

elixir/LEDC_Example/lib/LEDC_Example.ex

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+#
+# This file is part of AtomVM.
+#
+# Copyright 2022 Winford (Uncle Grumpy) <dwinford@proton.me>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later
+#
+
+defmodule LedcExample do
+  @moduledoc """
+  Ledc_example for Elixir.
+  """
+
+  @test_duty 4000
+  @test_fade_time 3000
+
+  @high_speed_timer 0
+  @low_speed_timer 1
+
+  # Change to match GPIO pins of your LEDs
+  @led_1 18
+  @led_2 19
+  @led_3 4
+  @led_4 5
+
+  def start do
+    ledc_hs_timer = [
+      {:duty_resolution, 13},
+      {:freq_hz, 5000},
+      {:speed_mode,  LEDC.high_speed_mode},
+      {:timer_num, @high_speed_timer}
+    ]
+
+    :ok = LEDC.timer_config(ledc_hs_timer)
+
+    ledc_ls_timer = [
+      {:duty_resolution, 13},
+      {:freq_hz, 5000},
+      {:speed_mode,  LEDC.low_speed_mode},
+      {:timer_num, @low_speed_timer}
+    ]
+
+    :ok = LEDC.timer_config(ledc_ls_timer)
+
+    ledc_channel = [
+      [
+        {:channel, 0},
+        {:duty, 0},
+        {:gpio_num, @led_1},
+        {:speed_mode,  LEDC.high_speed_mode},
+        {:hpoint, 0},
+        {:timer_sel, @high_speed_timer}
+      ],
+      [
+        {:channel, 1},
+        {:duty, 0},
+        {:gpio_num, @led_2},
+        {:speed_mode,  LEDC.high_speed_mode},
+        {:hpoint, 0},
+        {:timer_sel, @high_speed_timer}
+      ],
+      [
+        {:channel, 2},
+        {:duty, 0},
+        {:gpio_num, @led_3},
+        {:speed_mode,  LEDC.low_speed_mode},
+        {:hpoint, 0},
+        {:timer_sel, @low_speed_timer}
+      ],
+      [
+        {:channel, 3},
+        {:duty, 0},
+        {:gpio_num, @led_4},
+        {:speed_mode,  LEDC.low_speed_mode},
+        {:hpoint, 0},
+        {:timer_sel, @low_speed_timer}
+      ]
+    ]
+
+    Enum.each(ledc_channel, fn channel_config -> :ok = LEDC.channel_config(channel_config) end)
+    :ok = LEDC.fade_func_install(0)
+    loop(ledc_channel)
+  end
+
+  def loop(ledc_channel) do
+    :io.format('1. LEDC fade up to duty = ~p~n', [@test_duty])
+    Enum.each(ledc_channel, fn channel_config -> do_stage_1(channel_config) end)
+    Process.sleep(@test_fade_time)
+
+    :io.format('2. LEDC fade down to duty = 0~n')
+    Enum.each(ledc_channel, fn channel_config -> do_stage_2(channel_config) end)
+    Process.sleep(@test_fade_time)
+
+    :io.format('3. LEDC set duty = ~p without fade~n', [@test_duty])
+    Enum.each(ledc_channel, fn channel_config -> do_stage_3(channel_config) end)
+    Process.sleep(@test_fade_time)
+
+    :io.format('4. LEDC set duty = 0 without fade~n')
+    Enum.each(ledc_channel, fn channel_config -> do_stage_4(channel_config) end)
+    Process.sleep(@test_fade_time)
+
+    loop(ledc_channel)
+  end
+
+  defp do_stage_1(channel_config) do
+    speed_mode = :proplists.get_value(:speed_mode, channel_config)
+    channel = :proplists.get_value(:channel, channel_config)
+    :ok = LEDC.set_fade_with_time(speed_mode, channel, @test_duty, @test_fade_time)
+    :ok = LEDC.fade_start(speed_mode, channel, LEDC.fade_no_wait)
+  end
+
+  defp do_stage_2(channel_config) do
+    speed_mode = :proplists.get_value(:speed_mode, channel_config)
+    channel = :proplists.get_value(:channel, channel_config)
+    :ok = LEDC.set_fade_with_time(speed_mode, channel, 0, @test_fade_time)
+    :ok = LEDC.fade_start(speed_mode, channel, LEDC.fade_no_wait)
+  end
+
+  defp do_stage_3(channel_config) do
+    speed_mode = :proplists.get_value(:speed_mode, channel_config)
+    channel = :proplists.get_value(:channel, channel_config)
+    :ok = LEDC.set_duty(speed_mode, channel, @test_duty)
+    :ok = LEDC.update_duty(speed_mode, channel)
+  end
+
+  defp do_stage_4(channel_config) do
+    speed_mode = :proplists.get_value(:speed_mode, channel_config)
+    channel = :proplists.get_value(:channel, channel_config)
+    :ok = LEDC.set_duty(speed_mode, channel, 0)
+    :ok = LEDC.update_duty(speed_mode, channel)
+  end
+end

elixir/LEDC_Example/mix.exs

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+defmodule LedcExample.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :LEDC_Example,
+      version: "0.1.0",
+      elixir: "~> 1.13",
+      start_permanent: Mix.env() == :prod,
+      deps: deps()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      extra_applications: [:logger]
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      {:exatomvm, git: "https://github.com/atomvm/ExAtomVM/"}
+    ]
+  end
+end