Read a whole array of objects !

Forum 2005-2010 (read only) Software Syntax & Programs
1

greetings ppl,

I am using Visual studio 2008 and I write to the serial port an array of objects via WriteFile API function.The problem I am facing is "how I can read this array in my arduinoBT for further process ?" ... I give you a simple example so you can undestand me :

I have the follow class :

class ValueClass
{
private:
  int Value;
public:
  void setValue(int aNumber){Value = aNumber}
  int getValue(){return Value;}
}

I am filling an array of objects :

ValueClass allValues = new ValueClass [3];

and finally I am sending the array as follows :

hSerial = CreateFile("COM1",
                  GENERIC_WRITE,
                  0,
                  0,
                  OPEN_EXISTING,
                  FILE_ATTRIBUTE_NORMAL,
                  0);

ok = WriteFile(hSerial,allValues, 3 * sizeof(ValueClass), &dwBytesWritten, NULL);

Now, I have to read the array(allValues) in my board...
any suggestion ?

2

As far as the Arduino is concerned, there's nothing to read: "Value" is private, and "setValue" and "getValue" are methods which would make no sense to Arduino.

I am filling an array of objects :

You're just instantiating an array of objects, surely?

Otherwise, the way you read an array is the same way you eat an elephant: one bite at a time.

3

I mean, how I can reconstruct my original array?..
I know that I can read 1 byte at a time and I wrote a simple sketch trying to read the whole array.

class ValueClass
{
private:
  int Value;
public:
  void setValue(int aNumber){Value = aNumber}
  int getValue(){return Value;}
} 

byte buffer[3*sizeof(ValueClass)];

void setup()
{
Serial.begin(115200);
}
void loop()
{
while (Serial.available() < 3*sizeof(ValueClass) ){}

for(int i=0; i<3*sizeof(ValueClass); i++)
   buffer[i] = Serial.read(); 
}

So I remake my question..How I can reconstruct the buffer into an array of ValueClass Objects ?

4

How I can reconstruct the buffer into an array of ValueClass Objects ?

You can't. You are trying to marshal and unmarshal a object across completely different operating systems.

How would you expect the getValue function to operate on the Arduino?

5

First you need to make sure you know what the endianess of both parts of the transfer is.
If it's the same, then it's dead easy; if they're different, then it's very slightly less dead easy.
And make sure an "int" is the same size on both platforms...