Added the IOManager class

src/app/IOManager.cpp

@@ -0,0 +1,16 @@
+#include "IOManager.h"
+
+IOManager::IOManager(PCF8574 &pcf) : _pcf(pcf)
+{
+}
+
+PCF8574 &IOManager::getPcf()
+{
+  return _pcf;
+}
+
+void IOManager::setISROnIOChange(void (*isrFunc)(), Pin pin)
+{
+  pinMode(pin, INPUT);
+  attachInterrupt(digitalPinToInterrupt(pin), isrFunc, FALLING);
+}

src/app/IOManager.h

@@ -0,0 +1,17 @@
+#ifndef IOMANAGER_H
+#define IOMANAGER_H
+#include "definition.h"
+#include <PCF8574.h>
+
+class IOManager
+{
+  public:
+    IOManager(PCF8574 &pcf);
+    void setISROnIOChange(void (*isrFunc)(), Pin pin = GPIO_0);
+    PCF8574 &getPcf();
+  private:
+    PCF8574 &_pcf;
+  protected:
+};
+
+#endif //IOMANAGER_H