MattGr:
Can someone point me to code that declares instances of a class within another class?
Sure!
I want to instantiate them in the encompassing classes' constructor and make them global to the instance.
what? If it's global, it's not an instance variable.
In any case: you use the colon for this. You can also use the colon syntax for primitive types. I do this all the time - it's a great way to assign pins to networks of objects. Remember that you don't talk to the pins in the constructor. This must be done via the setup method, which is invoked after hardware initialization is done. The constructor is purely for setting up the numbers to be used. I like to give each of my objects their own setup and loop, even if those methods do nothing.
class A {
const int pin;
A(int attachPin) : pin(attachPin) {
// other constructor code goes here
}
void setup() {
pinMode(pin, INPUT_PULLUP);
}
};
class B {
A myA;
B(int a_attach) : myA(a_attach) {
// other constructor code goes here
}
void setup() {
myA.setup();
}
};
B quux(7); // attach quux to pin 7
void setup() {
quux.setup();
}
See the code linked to in my sig for more.