Functional interrupt (#1728)

* Initial

* Implementation

* Add to CMakelist.txt

* Add example

* Add IRAM_ATTR

libraries/ESP32/examples/GPIO/FunctionalInterrupt/FunctionalInterrupt.ino

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+#include <Arduino.h>
+#include <FunctionalInterrupt.h>
+
+#define BUTTON1 16
+#define BUTTON2 17
+
+class Button
+{
+public:
+	Button(uint8_t reqPin) : PIN(reqPin){
+		pinMode(PIN, INPUT_PULLUP);
+		attachInterrupt(PIN, std::bind(&Button::isr,this), FALLING);
+	};
+	~Button() {
+		detachInterrupt(PIN);
+	}
+
+	void IRAM_ATTR isr() {
+		numberKeyPresses += 1;
+		pressed = true;
+	}
+
+	void checkPressed() {
+		if (pressed) {
+			Serial.printf("Button on pin %u has been pressed %u times\n", PIN, numberKeyPresses);
+			pressed = false;
+		}
+	}
+
+private:
+	const uint8_t PIN;
+    volatile uint32_t numberKeyPresses;
+    volatile bool pressed;
+};
+
+Button button1(BUTTON1);
+Button button2(BUTTON2);
+
+
+void setup() {
+    Serial.begin(115200);
+}
+
+void loop() {
+	button1.checkPressed();
+	button2.checkPressed();
+}

libraries/ESP32/examples/GPIO/GPIOInterrupt/GPIOInterrupt.ino

@@ -0,0 +1,45 @@
+#include <Arduino.h>
+
+struct Button {
+    const uint8_t PIN;
+    uint32_t numberKeyPresses;
+    bool pressed;
+};
+
+Button button1 = {23, 0, false};
+Button button2 = {18, 0, false};
+
+void IRAM_ATTR isr(void* arg) {
+    Button* s = static_cast<Button*>(arg);
+    s->numberKeyPresses += 1;
+    s->pressed = true;
+}
+
+void IRAM_ATTR isr() {
+    button2.numberKeyPresses += 1;
+    button2.pressed = true;
+}
+
+void setup() {
+    Serial.begin(115200);
+    pinMode(button1.PIN, INPUT_PULLUP);
+    attachInterruptArg(button1.PIN, isr, &button1, FALLING);
+    pinMode(button2.PIN, INPUT_PULLUP);
+    attachInterrupt(button2.PIN, isr, FALLING);
+}
+
+void loop() {
+    if (button1.pressed) {
+        Serial.printf("Button 1 has been pressed %u times\n", button1.numberKeyPresses);
+        button1.pressed = false;
+    }
+    if (button2.pressed) {
+        Serial.printf("Button 2 has been pressed %u times\n", button2.numberKeyPresses);
+        button2.pressed = false;
+    }
+    static uint32_t lastMillis = 0;
+    if (millis() - lastMillis > 10000) {
+      lastMillis = millis();
+      detachInterrupt(button1.PIN);
+    }
+}