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Pixy2 how to decode blocks

Pixy Software
#1

Hi, Just got the Pixy2, I have it working with an Arduino. It’s picking up colour blocks well and sending back block details to the Serial Print page. What I need to do now is extract the x, y, width, height etc data from these blocks (to manage my servo positions) but I keep getting error messages saying blocks do not have ‘width’ or ‘x’ or ‘y’ etc properties. The only one that is recognised is the ‘print’ property. I had little hair to start with, now it’s much less as I’ve been trying everything for days now.
Please, can someone help?
Thank you
Richard

Block Signature question using pixy.ccc.numBlocks
#2

Hello Richard,
Bear in mind that you need to refer to the ccc object within the Pixy object. See the code below – esp the “for example” comment and lines following:

void loop()
{ 
  int i; 
  // grab blocks!
  pixy.ccc.getBlocks();
  
  // If there are detect blocks, print them!
  if (pixy.ccc.numBlocks)
  {
    Serial.print("Detected ");
    Serial.println(pixy.ccc.numBlocks);
    for (i=0; i<pixy.ccc.numBlocks; i++)
    {
      Serial.print("  block ");
      Serial.print(i);
      Serial.print(": ");
      pixy.ccc.blocks[i].print();
      // for example....
      Serial.println(pixy.ccc.blocks[i].m_x);
      Serial.println(pixy.ccc.blocks[i].m_y); // etc...
    }
  }  
}

Here’s the API – it shows you what fields are available in each block:

https://docs.pixycam.com/wiki/doku.php?id=wiki:v2:ccc_api

Edward

#3

Hi Edward,
That’s wonderful, many thanks. It was the ‘.m_x’ bit that I was missing. So now I can do:
myvariable=pixy.ccc.blocks[I].m_x; (…y, width, height etc)
and then the maths in the normal way.
Thank you
Richard

#4

I made the same mistake, refering to blocks, but you have to use blocks[#].x instead.