Initial commit of mostly working library.

button.h

@@ -0,0 +1,107 @@
+/**
+ * @file button.h
+ * @author Adam Wonak (https://github.com/awonak)
+ * @brief for interacting with trigger / gate inputs.
+ * @version 0.1
+ * @date 2025-04-20
+ *
+ * Provide methods to convey curent state (HIGH / LOW) and change in state (disengaged, engageing, engaged, disengaging).
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+#ifndef BUTTON_H
+#define BUTTON_H
+
+#include <Arduino.h>
+
+class Button {
+   protected:
+    typedef void (*CallbackFunction)(void);
+    CallbackFunction on_press;
+
+   public:
+    // Enum constants for active change in button state.
+    enum ButtonChange {
+        CHANGE_UNCHANGED,
+        CHANGE_PRESSED,
+        CHANGE_RELEASED,
+    };
+
+    Button() {}
+    Button(int pin) { Init(pin); }
+    ~Button() {}
+
+    /**
+     * Initializes a CV Input object.
+     *
+     * @param pin gpio pin for the cv output.
+     */
+    void Init(uint8_t pin) {
+        pinMode(pin, INPUT_PULLUP);
+        pin_ = pin;
+    }
+
+    /**
+     * Provide a handler function for executing when button is pressed.
+     * 
+     * @param f Callback function to attach push behavior to this button.
+     */
+    void AttachPressHandler(CallbackFunction f) {
+        on_press = f;
+    }
+
+    // Execute the press callback.
+    void OnPress() {
+        if (on_press != NULL) {
+            on_press();
+        }
+    }
+
+    /**
+     * Read the state of the cv input.
+     */
+    void Process() {
+        int read = digitalRead(pin_);
+
+        bool debounced = (millis() - last_press_) > DEBOUNCE_MS;
+        bool pressed = read == 0 && old_read_ == 1 && debounced;
+        bool released = read == 1 && old_read_ == 0 && debounced;
+        // Update variables for next loop
+        last_press_ = (pressed || released) ? millis() : last_press_;
+
+        // Determine current clock input state.
+        change_ = CHANGE_UNCHANGED;
+        if (pressed) {
+            change_ = CHANGE_PRESSED;
+            on_ = true;
+        } else if (released) {
+            change_ = CHANGE_RELEASED;
+            on_ = false;
+        }
+        old_read_ = read;
+    }
+
+    /**
+     * Get the state change for the button.
+     *
+     * @return ButtonChange
+     */
+    inline ButtonChange Change() { return change_; }
+
+    /**
+     * Current cv state represented as a bool.
+     *
+     * @return true if cv signal is high, false if cv signal is low
+     */
+    inline bool On() { return on_; }
+
+   private:
+    uint8_t pin_;
+    uint8_t old_read_;
+    unsigned long last_press_;
+    ButtonChange change_ = CHANGE_UNCHANGED;
+    bool on_;
+};
+
+#endif