Using classes with the Arduino

Question

I'm trying to use class objects with the Arduino, but I keep running into problems. All I want to do is declare a class and create an object of that class. What would an example be?

Answer 1

On Arduino 1.0, this compiles just fine:

class A {   public:    int x;    virtual void f() { x=1; } };  class B : public A {   public:     int y;     virtual void f() { x=2; } };   A *a; B *b; const int TEST_PIN = 10;  void setup() {    a=new A();     b=new B();    pinMode(TEST_PIN,OUTPUT); }  void loop() {    a->f();    b->f();    digitalWrite(TEST_PIN,(a->x == b->x) ? HIGH : LOW); } 

Answer 2

There is an excellent tutorial on how to create a library for the Arduino platform. A library is basically a class, so it should show you how its all done.

On Arduino you can use classes, but there are a few restrictions:

• No new and delete keywords
• No exceptions
• No libstdc++, hence no standard functions, templates or classes

You also need to make new files for your classes, you can't just declare them in your main sketch. You also will need to close the Arduino IDE when recompiling a library. That is why I use Eclipse as my Arduino IDE.