Download the latest Arduino library “arduino_pixy2-x.y.z.zip” here. Bring up the Arduino IDE and import the Pixy library by selecting Sketch➜Import Library in the Arduino IDE, and then browse to the Arduino zip file that you just downloaded.

Before installing a new version of the Arduino Library, it's recommended that you delete the existing library. To do this, you can go into your C:\Users\<yourname>\Documents\Arduino\libraries (or similar directory, <yourname>/Documents/Arduino in OSX and Linux) and remove the Pixy directory. Then re-run the Arduino IDE.

Be sure to include these two files:

#include <SPI.h>
#include <Pixy2.h>

You need to declare an instance of a Pixy object outside of your setup() and loop() functions:

Pixy2 pixy;

The most important method in the Arduino library is getBlocks(), which returns the number of objects Pixy has detected. You can then look in the pixy.ccc.blocks[] array for information about each detected object (one array member for each detected object.) Each array member (i) contains the following fields:

• pixy.ccc.blocks[i].m_signature The signature number of the detected object (1-7 for normal signatures)
• pixy.ccc.blocks[i].m_x The x location of the center of the detected object (0 to 316)
• pixy.ccc.blocks[i].m_y The y location of the center of the detected object (0 to 208)
• pixy.ccc.blocks[i].m_width The width of the detected object (1 to 316)
• pixy.ccc.blocks[i].m_height The height of the detected object (1 to 208)
• pixy.ccc.blocks[i].m_angle The angle of the object detected object if the detected object is a color code (-180 to 180).
• pixy.ccc.blocks[i].m_index The tracking index of the block
• pixy.ccc.blocks[i].m_age The number of frames the block has been tracked.
• pixy.ccc.blocks[i].print() A member function that prints the detected object information to the serial port

getBlocks() accepts an optional number argument (uint16_t) that indicates the maximum number of blocks you want getBlocks() to return.

This method sets the pan/tilt servos that are plugged into Pixy's two servo ports. The two arguments s0 and s1 can range from 0 to 1000.

This method sets the brightness (exposure) of Pixy's camera. The brightness argument can range between 0 and 255 with 255 being the brightest setting.

This method sets the RGB LED on front of Pixy. The r, g and b arguments can range between 0 and 255.