Examples: Adds Button example. Closes #5.

Author: aserebryakov

examples/Button/Button.ino

@@ -0,0 +1,100 @@
+// MIT License
+//
+// Copyright (c) 2025 Alexander Serebryakov
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+// This example demonstrates how to work with Button object.
+//
+// Hardware:
+// - Arduino
+// - Button
+//
+// Setup:
+// - Button is connected to D2
+
+#include <Arduino.h>
+#include <CppComponentsLibrary.h>
+
+// Instantiate a hardware api object.
+HwApiImpl hw_api{};
+
+constexpr int BUTTON_PIN{2};
+
+// Class is used to implement callbacks and store the internal state.
+//
+// Inheritance from Device class isn't necessary, but it provides default functions
+// to be implemented to have a consistent API
+class ButtonLogic : public Device {
+public:
+  ButtonLogic() : button{
+    {BUTTON_PIN, true}, // Setting DT pin to PULL_UP mode
+    hw_api, // Providing to button instance of HwApi to be used to setup pin and read pin value
+    {onPushButton, this}, // Connecting button push event to callback function and this object
+    {onReleaseButton, this}, // Connecting button release event to callback function and this object 
+    }
+  {
+  }
+
+  virtual ~ButtonLogic() override = default;
+
+  // Function to be called from setup() 
+  virtual void begin() override {
+    button.begin(); // Initializes pin
+  }
+
+  // Function to be called from loop()
+  virtual void loop() override {
+    button.loop(); // Reads pin value and calls callback funcitons
+  }
+
+  // Function that is called when button is pushed
+  static void onPushButton(void* self) {
+    // Callback function is unaware of the pointer type so we cast it to current object type.
+    auto& logic{*static_cast<ButtonLogic*>(self)};
+    logic.counter++;
+    Serial.print("Button pushed : ");
+    Serial.println(logic.counter);
+  }
+
+  // Function that is called when when button is released
+  static void onReleaseButton(void* self) {
+    auto& logic{*static_cast<ButtonLogic*>(self)};
+    logic.counter--;
+    Serial.print("Button released : ");
+    Serial.println(logic.counter);
+  }
+
+private:
+  Button button;
+  int counter{0};
+};
+
+// Instantiating the object
+ButtonLogic logic{};
+
+void setup() {
+  Serial.begin(57600);
+  logic.begin();
+}
+
+void loop() {
+  logic.loop();
+  delay(10);
+}