Arduino initiation of a class containing an array of a class - arrays

Question

hi so im making a hierarchy sort of structure for a robotic walker to make the number of servos manageable and im trying to create a Limb class that contains a number of servo classes (yes im using the built in servo Library but i want to also tweak the offset,scale ect. of the value for calibration purposes) anyway hear is my code.
the problem is the Limb Class initiator (bottom 4 lines) i usually dont like just straight up asking for the correct line of code and prefer to figure it out but iv tried everything i can think of
PS i apolagise for any crap spelling and thanks
class ServoConfig{
public :
float Offset;
float Scale;
bool Inversed;
Servo ServoV;
ServoConfig (float InOffset, float InScale, bool InInversed,int Pin){
float Offset = InOffset;
float Scale = InScale;
bool Inversed = InInversed;
ServoV.attach(Pin);
}
void WriteToServo(float Angle){
if (Inversed){
ServoV.write((180-Angle)/Scale + Offset);
}
else{
ServoV.write(Angle/Scale + Offset);
}
}
};
class Limb{
ServoConfig Servos[];
Limb (ServoConfig InServos[]){
ServoConfig Servos[] = InServos;
}
};

Answer 1

It's not so easy in C++ and on Arduino it's even harder.
But first you have loads of mistakes in code. For example shadowing class attibutes by local variables:
ServoConfig (float InOffset, float InScale, bool InInversed,int Pin) {
float Offset = InOffset; // this will create new local variable and hides that one in class with the same name
float Scale = InScale; // this too
bool Inversed = InInversed; // and this too
The same is in Limb constructor, but it doesn't work anyways.
And how it can be working? You can use something like this:
#include <Servo.h>
class ServoConfig {
public :
float Offset;
float Scale;
bool Inversed;
Servo ServoV;
ServoConfig (float InOffset, float InScale, bool InInversed,int Pin)
: Offset { InOffset }
, Scale { InScale }
, Inversed { InInversed }
{
ServoV.attach(Pin); // it might have to be attached in setup() as constructors are called before main()
}
void WriteToServo(float Angle){
if (Inversed) {
ServoV.write((180-Angle)/Scale + Offset);
} else {
ServoV.write(Angle/Scale + Offset);
}
}
};
ServoConfig servos[] = {{10,10,0,9},{0,1,0,10}}; // this makes servos of size two and calls constructors
class Limb {
public:
ServoConfig * servos_begin;
ServoConfig * servos_end;
Limb(ServoConfig * beg, ServoConfig * end)
: servos_begin { beg }
, servos_end { end }
{;}
ServoConfig * begin() { return servos_begin; }
ServoConfig * end() { return servos_end; }
size_t size() { return servos_end - servos_begin; }
};
// much better than using sizeof(array)/sizeof(array[0]):
template <class T, size_t size> size_t arraySize(T(&)[size]) { return size; }
// create and construct Limb instance:
Limb limb { servos, servos + arraySize(servos)};
void setup(){
Serial.begin(9600);
}
void loop(){
Serial.println("starting...");
for (ServoConfig & servo : limb) { // this uses begin() and end() methods
servo.WriteToServo(90);
}
// or directly with array[]
for (ServoConfig & servo : servos) {
servo.WriteToServo(40);
}
}