first commit

lib/README

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+
+This directory is intended for project specific (private) libraries.
+PlatformIO will compile them to static libraries and link into executable file.
+
+The source code of each library should be placed in an own separate directory
+("lib/your_library_name/[here are source files]").
+
+For example, see a structure of the following two libraries `Foo` and `Bar`:
+
+|--lib
+|  |
+|  |--Bar
+|  |  |--docs
+|  |  |--examples
+|  |  |--src
+|  |     |- Bar.c
+|  |     |- Bar.h
+|  |  |- library.json (optional, custom build options, etc) https://docs.platformio.org/page/librarymanager/config.html
+|  |
+|  |--Foo
+|  |  |- Foo.c
+|  |  |- Foo.h
+|  |
+|  |- README --> THIS FILE
+|
+|- platformio.ini
+|--src
+   |- main.c
+
+and a contents of `src/main.c`:
+```
+#include <Foo.h>
+#include <Bar.h>
+
+int main (void)
+{
+  ...
+}
+
+```
+
+PlatformIO Library Dependency Finder will find automatically dependent
+libraries scanning project source files.
+
+More information about PlatformIO Library Dependency Finder
+- https://docs.platformio.org/page/librarymanager/ldf.html

lib/pixy/Pixy.h

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+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This file is for defining the SPI-related classes.  It's called Pixy.h instead
+// of Pixy_SPI.h because it's the default/recommended communication method
+// with Arduino.  This class assumes you are using the ICSP connector to talk to 
+// Pixy from your Arduino.  For more information go to:
+//
+//http://cmucam.org/projects/cmucam5/wiki/Hooking_up_Pixy_to_a_Microcontroller_(like_an_Arduino)
+//
+
+#ifndef PIXY_H
+#define PIXY_H
+
+#include "TPixy.h"
+#include "SPI.h"
+
+
+#define PIXY_SYNC_BYTE              0x5a
+#define PIXY_SYNC_BYTE_DATA         0x5b
+#define PIXY_BUF_SIZE               16
+
+template <class BufType> struct CircularQ
+{
+  CircularQ()
+  {
+    len = 0;
+	writeIndex = 0;
+	readIndex = 0;
+  }
+  
+  bool read(BufType *c)
+  {
+    if (len)
+	{
+      *c = buf[readIndex++];
+      len--;
+      if (readIndex==PIXY_BUF_SIZE)
+        readIndex = 0;
+	  return true;
+	}
+	else
+	  return false;
+  }
+  
+  uint8_t freeLen()
+  {
+    return PIXY_BUF_SIZE-len;
+  } 
+  
+  bool write(BufType c)
+  {
+    if (freeLen()==0)
+      return false;
+
+    buf[writeIndex++] = c;
+	len++;
+    if (writeIndex==PIXY_BUF_SIZE)
+      writeIndex = 0;
+    return true;
+  }
+
+    BufType buf[PIXY_BUF_SIZE];
+    uint8_t len;
+    uint8_t writeIndex;
+    uint8_t readIndex;
+};
+
+class LinkSPI
+{
+  public:
+    void init()
+    {
+      SPI.begin();
+
+      #ifdef __SAM3X8E__
+      // DUE clock divider //
+      SPI.setClockDivider(84);
+      #else
+      // Default clock divider //
+      SPI.setClockDivider(SPI_CLOCK_DIV16);
+      #endif
+    }
+    
+	uint16_t getWord()
+    {
+      // ordering is different (big endian) because Pixy is sending 16 bits through SPI 
+      // instead of 2 bytes in a 16-bit word as with I2C
+      uint16_t w;
+
+	  if (inQ.read(&w))
+	    return w;
+		
+	  return getWordHw();
+    }
+
+    uint8_t getByte()
+    {
+      return SPI.transfer(0x00);
+    }
+    
+    int8_t send(uint8_t *data, uint8_t len)
+    {
+      int i;
+
+      // check to see if we have enough space in our circular queue
+      if (outQ.freeLen()<len)
+        return -1;
+
+      for (i=0; i<len; i++)
+		outQ.write(data[i]);
+	  flushSend();
+      return len;
+    }
+
+    void setArg(uint16_t arg)
+    {
+    }
+
+  private:
+    uint16_t getWordHw()
+    {
+      // ordering is different (big endian) because Pixy is sending 16 bits through SPI 
+      // instead of 2 bytes in a 16-bit word as with I2C
+      uint16_t w;
+      uint8_t c, cout = 0;
+		
+	  if (outQ.read(&cout))
+        w = SPI.transfer(PIXY_SYNC_BYTE_DATA);
+      else
+        w = SPI.transfer(PIXY_SYNC_BYTE);
+		
+      w <<= 8;
+      c = SPI.transfer(cout);
+      w |= c;
+
+      return w;
+    }
+
+	void flushSend()
+    {
+      uint16_t w;
+      while(outQ.len)
+      {
+        w = getWordHw();
+		inQ.write(w);
+	  }
+	}
+	
+	// we need a little circular queues for both directions
+	CircularQ<uint8_t> outQ;
+	CircularQ<uint16_t> inQ;
+};
+
+
+typedef TPixy<LinkSPI> Pixy;
+
+#endif

lib/pixy/PixyI2C.h

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+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This file is for defining the link class for I2C communications.  
+//
+// Note, the PixyI2C class takes an optional argument, which is the I2C address 
+// of the Pixy you want to talk to.  The default address is 0x54 (used when no 
+// argument is used.)  So, for example, if you wished to talk to Pixy at I2C 
+// address 0x55, declare like this:
+//
+// PixyI2C pixy(0x55);
+//
+
+#ifndef _PIXYI2C_H
+#define _PIXYI2C_H
+
+#include "TPixy.h"
+#include "Wire.h"
+
+#define PIXY_I2C_DEFAULT_ADDR           0x54  
+
+class LinkI2C
+{
+public:
+  void init()
+  {
+    Wire.begin();
+  }
+  void setArg(uint16_t arg)
+  {
+    if (arg==PIXY_DEFAULT_ARGVAL)
+      addr = PIXY_I2C_DEFAULT_ADDR;
+	else
+	  addr = arg;
+  }
+  uint16_t getWord()
+  {
+    uint16_t w;
+	uint8_t c;
+	Wire.requestFrom((int)addr, 2);
+    c = Wire.read();
+    w = Wire.read();
+    w <<= 8;
+    w |= c; 
+    return w;
+  }
+  uint8_t getByte()
+  {
+	Wire.requestFrom((int)addr, 1);
+	return Wire.read();
+  }
+
+  int8_t send(uint8_t *data, uint8_t len)
+  {
+    Wire.beginTransmission(addr);
+    Wire.write(data, len);
+	Wire.endTransmission();
+	return len;
+  }
+	
+private:
+  uint8_t addr;
+};
+
+typedef TPixy<LinkI2C> PixyI2C;
+
+#endif

lib/pixy/PixySPI_SS.h

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+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This file is for defining the link class for SPI with Slave Select.  The 
+// default communication for Arduino is through the ICSP connector, which uses
+// SPI without a slave select.  The LinkSPI_SS allows you to use a slave select
+// so you can share the SPI port with other devices, or use multiple Pixys. 
+//
+// Note, the PixySPI_SS class takes an optional argument, which is the pin 
+// number of the slave select signal you wish to use.  The default pin is the 
+// SS pin (used when no argument is used.)  So, for example, if you wished to 
+// use pin 14 for slave select, declare like this:
+//
+// PixySPI_SS pixy(14);
+//
+
+#ifndef PIXYSPI_SS_H
+#define PIXYSPI_SS_H
+
+#include "TPixy.h"
+#include "SPI.h"
+
+
+#define PIXY_SYNC_BYTE              0x5a
+#define PIXY_SYNC_BYTE_DATA         0x5b
+#define PIXY_OUTBUF_SIZE            6
+
+class LinkSPI_SS
+{
+  public:
+    void init()
+    {
+      outLen = 0;
+      SPI.begin();
+
+      #ifdef __SAM3X8E__
+      // DUE clock divider //
+      SPI.setClockDivider(84);
+      #else
+      // Default clock divider //
+      SPI.setClockDivider(SPI_CLOCK_DIV16);
+      #endif
+    }
+    
+    uint16_t getWord()
+    {
+      // ordering is different because Pixy is sending 16 bits through SPI 
+      // instead of 2 bytes in a 16-bit word as with I2C
+      uint16_t w;
+      uint8_t c, cout = 0;
+	  
+	  // assert slave select
+	  digitalWrite(ssPin, LOW);
+
+      if (outLen)
+      {
+        w = SPI.transfer(PIXY_SYNC_BYTE_DATA);
+        cout = outBuf[outIndex++];
+        if (outIndex==outLen)
+          outLen = 0; 
+      }
+      else
+        w = SPI.transfer(0);
+
+      w <<= 8;
+      c = SPI.transfer(cout);
+      w |= c;
+
+	  // negate slave select
+	  digitalWrite(ssPin, HIGH);
+      return w;
+    }
+	
+    uint8_t getByte() // this shouldn't be called normally
+	// It should only be called if we get out of sync, but with slave select
+	// we should stay in sync 
+    {
+	  uint8_t c;
+ 	  // assert slave select
+	  digitalWrite(ssPin, LOW);
+      c = SPI.transfer(0x00);
+ 	  // negate slave select
+	  digitalWrite(ssPin, HIGH);
+	  
+	  return c;
+   }
+    
+    int8_t send(uint8_t *data, uint8_t len)
+    {
+      if (len>PIXY_OUTBUF_SIZE || outLen!=0)
+        return -1;
+      memcpy(outBuf, data, len);
+      outLen = len;
+      outIndex = 0;
+      return len;
+    }
+
+    void setArg(uint16_t arg)
+    {
+      if (arg==PIXY_DEFAULT_ARGVAL)
+        ssPin = SS; // default slave select pin
+	  else
+	    ssPin = arg;
+    }
+
+  private:
+    uint8_t outBuf[PIXY_OUTBUF_SIZE];
+    uint8_t outLen;
+    uint8_t outIndex;
+	uint16_t ssPin;
+};
+
+
+typedef TPixy<LinkSPI_SS> PixySPI_SS;
+
+#endif

lib/pixy/PixyUART.h

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+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This file is for defining the link class for UART communications.  
+//
+
+#ifndef _PIXYUART_H
+#define _PIXYUART_H
+
+#include "TPixy.h"
+#include "Arduino.h"
+
+class LinkUART
+{
+public:
+  void init()
+  {
+    Serial1.begin(19200);
+  }
+  void setArg(uint16_t arg)
+  {
+  }
+  uint16_t getWord()
+  {
+    int16_t u, v;
+	
+	while(1)
+    {
+      u = Serial1.read();
+      if (u>=0)
+        break;
+    }
+    while(1)
+    {
+      v = Serial1.read();
+      if (v>=0)
+        break;
+    }
+    v <<= 8;
+    v |= u&0xff; 
+    return v;
+  }
+  uint8_t getByte()
+  {
+    int16_t u;
+	
+	while(1)
+    {
+      u = Serial1.read();
+      if (u>=0)
+        break;
+    }
+	return (uint8_t)u;
+  }
+  int8_t send(uint8_t *data, uint8_t len)
+  {
+    return Serial1.write(data, len);
+  }  
+};
+
+typedef TPixy<LinkUART> PixyUART;
+
+#endif

lib/pixy/TPixy.h

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+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This file is for defining the Block struct and the Pixy template class.
+// (TPixy).  TPixy takes a communication link as a template parameter so that 
+// all communication modes (SPI, I2C and UART) can share the same code.  
+//
+
+#ifndef _TPIXY_H
+#define _TPIXY_H
+
+#include "Arduino.h"
+
+// Communication/misc parameters
+#define PIXY_INITIAL_ARRAYSIZE      30
+#define PIXY_MAXIMUM_ARRAYSIZE      130
+#define PIXY_START_WORD             0xaa55
+#define PIXY_START_WORD_CC          0xaa56
+#define PIXY_START_WORDX            0x55aa
+#define PIXY_MAX_SIGNATURE          7
+#define PIXY_DEFAULT_ARGVAL         0xffff
+
+// Pixy x-y position values
+#define PIXY_MIN_X                  0L
+#define PIXY_MAX_X                  319L
+#define PIXY_MIN_Y                  0L
+#define PIXY_MAX_Y                  199L
+
+// RC-servo values
+#define PIXY_RCS_MIN_POS            0L
+#define PIXY_RCS_MAX_POS            1000L
+#define PIXY_RCS_CENTER_POS         ((PIXY_RCS_MAX_POS-PIXY_RCS_MIN_POS)/2)
+
+ 
+enum BlockType
+{
+	NORMAL_BLOCK,
+	CC_BLOCK
+};
+
+struct Block 
+{
+  // print block structure!
+  void print()
+  {
+    int i, j;
+    char buf[128], sig[6], d;
+	bool flag;	
+    if (signature>PIXY_MAX_SIGNATURE) // color code! (CC)
+	{
+      // convert signature number to an octal string
+      for (i=12, j=0, flag=false; i>=0; i-=3)
+      {
+        d = (signature>>i)&0x07;
+        if (d>0 && !flag)
+          flag = true;
+        if (flag)
+          sig[j++] = d + '0';
+      }
+      sig[j] = '\0';	
+      sprintf(buf, "CC block! sig: %s (%d decimal) x: %d y: %d width: %d height: %d angle %d\n", sig, signature, x, y, width, height, angle);
+    }			
+	else // regular block.  Note, angle is always zero, so no need to print
+      sprintf(buf, "sig: %d x: %d y: %d width: %d height: %d\n", signature, x, y, width, height);		
+    Serial.print(buf); 
+  }
+  uint16_t signature;
+  uint16_t x;
+  uint16_t y;
+  uint16_t width;
+  uint16_t height;
+  uint16_t angle;
+};
+
+
+
+template <class LinkType> class TPixy
+{
+public:
+  TPixy(uint16_t arg=PIXY_DEFAULT_ARGVAL);
+  ~TPixy();
+	
+  uint16_t getBlocks(uint16_t maxBlocks=1000);
+  int8_t setServos(uint16_t s0, uint16_t s1);
+  int8_t setBrightness(uint8_t brightness);
+  int8_t setLED(uint8_t r, uint8_t g, uint8_t b);
+  void init();
+  
+  Block *blocks;
+	
+private:
+  boolean getStart();
+  void resize();
+
+  LinkType link;
+  boolean  skipStart;
+  BlockType blockType;
+  uint16_t blockCount;
+  uint16_t blockArraySize;
+};
+
+
+template <class LinkType> TPixy<LinkType>::TPixy(uint16_t arg)
+{
+  skipStart = false;
+  blockCount = 0;
+  blockArraySize = PIXY_INITIAL_ARRAYSIZE;
+  blocks = (Block *)malloc(sizeof(Block)*blockArraySize);
+  link.setArg(arg);
+}
+
+template <class LinkType> void TPixy<LinkType>::init()
+{
+  link.init();
+}
+
+template <class LinkType> TPixy<LinkType>::~TPixy()
+{
+  free(blocks);
+}
+
+template <class LinkType> boolean TPixy<LinkType>::getStart()
+{
+  uint16_t w, lastw;
+ 
+  lastw = 0xffff;
+  
+  while(true)
+  {
+    w = link.getWord();
+    if (w==0 && lastw==0)
+	{
+      delayMicroseconds(10);
+	  return false;
+	}		
+    else if (w==PIXY_START_WORD && lastw==PIXY_START_WORD)
+	{
+      blockType = NORMAL_BLOCK;
+      return true;
+	}
+    else if (w==PIXY_START_WORD_CC && lastw==PIXY_START_WORD)
+	{
+      blockType = CC_BLOCK;
+      return true;
+	}
+	else if (w==PIXY_START_WORDX)
+	{
+	  Serial.println("reorder");
+	  link.getByte(); // resync
+	}
+	lastw = w; 
+  }
+}
+
+template <class LinkType> void TPixy<LinkType>::resize()
+{
+  blockArraySize += PIXY_INITIAL_ARRAYSIZE;
+  blocks = (Block *)realloc(blocks, sizeof(Block)*blockArraySize);
+}  
+		
+template <class LinkType> uint16_t TPixy<LinkType>::getBlocks(uint16_t maxBlocks)
+{
+  uint8_t i;
+  uint16_t w, checksum, sum;
+  Block *block;
+  
+  if (!skipStart)
+  {
+    if (getStart()==false)
+      return 0;
+  }
+  else
+	skipStart = false;
+	
+  for(blockCount=0; blockCount<maxBlocks && blockCount<PIXY_MAXIMUM_ARRAYSIZE;)
+  {
+    checksum = link.getWord();
+    if (checksum==PIXY_START_WORD) // we've reached the beginning of the next frame
+    {
+      skipStart = true;
+	  blockType = NORMAL_BLOCK;
+	  //Serial.println("skip");
+      return blockCount;
+    }
+	else if (checksum==PIXY_START_WORD_CC)
+	{
+	  skipStart = true;
+	  blockType = CC_BLOCK;
+	  return blockCount;
+	}
+    else if (checksum==0)
+      return blockCount;
+    
+	if (blockCount>blockArraySize)
+		resize();
+	
+	block = blocks + blockCount;
+	
+    for (i=0, sum=0; i<sizeof(Block)/sizeof(uint16_t); i++)
+    {
+	  if (blockType==NORMAL_BLOCK && i>=5) // skip 
+	  {
+		block->angle = 0;
+		break;
+	  }
+      w = link.getWord();
+      sum += w;
+      *((uint16_t *)block + i) = w;
+    }
+
+    if (checksum==sum)
+      blockCount++;
+    else
+      Serial.println("cs error");
+	
+	w = link.getWord();
+	if (w==PIXY_START_WORD)
+	  blockType = NORMAL_BLOCK;
+	else if (w==PIXY_START_WORD_CC)
+	  blockType = CC_BLOCK;
+	else
+      return blockCount;
+  }
+}
+
+template <class LinkType> int8_t TPixy<LinkType>::setServos(uint16_t s0, uint16_t s1)
+{
+  uint8_t outBuf[6];
+   
+  outBuf[0] = 0x00;
+  outBuf[1] = 0xff; 
+  *(uint16_t *)(outBuf + 2) = s0;
+  *(uint16_t *)(outBuf + 4) = s1;
+  
+  return link.send(outBuf, 6);
+}
+
+template <class LinkType> int8_t TPixy<LinkType>::setBrightness(uint8_t brightness)
+{
+  uint8_t outBuf[3];
+   
+  outBuf[0] = 0x00;
+  outBuf[1] = 0xfe; 
+  outBuf[2] = brightness;
+  
+  return link.send(outBuf, 3);
+}
+
+template <class LinkType> int8_t TPixy<LinkType>::setLED(uint8_t r, uint8_t g, uint8_t b)
+{
+  uint8_t outBuf[5];
+  
+  outBuf[0] = 0x00;
+  outBuf[1] = 0xfd; 
+  outBuf[2] = r;
+  outBuf[3] = g;
+  outBuf[4] = b;
+  
+  return link.send(outBuf, 5);
+}
+
+#endif

lib/pixy/examples/hello_world/hello_world.ino

@@ -0,0 +1,70 @@
+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This sketch is a good place to start if you're just getting started with 
+// Pixy and Arduino.  This program simply prints the detected object blocks 
+// (including color codes) through the serial console.  It uses the Arduino's 
+// ICSP port.  For more information go here:
+//
+// http://cmucam.org/projects/cmucam5/wiki/Hooking_up_Pixy_to_a_Microcontroller_(like_an_Arduino)
+//
+// It prints the detected blocks once per second because printing all of the 
+// blocks for all 50 frames per second would overwhelm the Arduino's serial port.
+//
+   
+#include <SPI.h>  
+#include <Pixy.h>
+
+// This is the main Pixy object 
+Pixy pixy;
+
+void setup()
+{
+  Serial.begin(9600);
+  Serial.print("Starting...\n");
+
+  pixy.init();
+}
+
+void loop()
+{ 
+  static int i = 0;
+  int j;
+  uint16_t blocks;
+  char buf[32]; 
+  
+  // grab blocks!
+  blocks = pixy.getBlocks();
+  
+  // If there are detect blocks, print them!
+  if (blocks)
+  {
+    i++;
+    
+    // do this (print) every 50 frames because printing every
+    // frame would bog down the Arduino
+    if (i%50==0)
+    {
+      sprintf(buf, "Detected %d:\n", blocks);
+      Serial.print(buf);
+      for (j=0; j<blocks; j++)
+      {
+        sprintf(buf, "  block %d: ", j);
+        Serial.print(buf); 
+        pixy.blocks[j].print();
+      }
+    }
+  }  
+}
+

lib/pixy/examples/i2c/i2c.ino

@@ -0,0 +1,63 @@
+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This sketch is like hello_world but uses I2C communications.  If you're
+// not sure what I2C is, run the hello_world sketch!
+//
+
+#include <Wire.h>
+#include <PixyI2C.h>
+
+
+PixyI2C pixy;
+// PixyI2C pixy(0x55); // You can set the I2C address through PixyI2C object 
+
+void setup()
+{
+  Serial.begin(9600);
+  Serial.print("Starting...\n");
+  
+  pixy.init();
+}
+
+
+void loop() 
+{ 
+  static int i = 0;
+  int j;
+  uint16_t blocks;
+  char buf[32]; 
+  
+  blocks = pixy.getBlocks();
+  
+  if (blocks)
+  {
+    i++;
+    
+    // do this (print) every 50 frames because printing every
+    // frame would bog down the Arduino
+    if (i%50==0)
+    {
+      sprintf(buf, "Detected %d:\n", blocks);
+      Serial.print(buf);
+      for (j=0; j<blocks; j++)
+      {
+        sprintf(buf, "  block %d: ", j);
+        Serial.print(buf); 
+        pixy.blocks[j].print();
+      }
+    }
+  }  
+}
+

lib/pixy/examples/led_cycle/led_cycle.ino

@@ -0,0 +1,54 @@
+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This sketch is demonstrates the setLED() function.  Running this sketch
+// will cycle the Pixy's RGB LED through its colors.   
+//
+
+#include <SPI.h>  
+#include <Pixy.h>
+
+Pixy pixy;
+
+void setup()
+{
+  Serial.begin(9600);
+  Serial.print("Starting...\n");
+
+  pixy.init();
+}
+
+void loop() 
+{ 
+   uint32_t i=0;
+   uint8_t r, g, b;
+   
+   while(1)
+   {
+     // calculate r, g, b such that it cycles through the colors
+     r = i&0xff;
+     g = (i*3)&0xff;
+     b = (i/3)&0xff;
+     pixy.setLED(r, g, b);
+     // We need to delay here because serial requests are handled 
+     // every frame period (20ms). If we don't delay, we'll
+     // overrun Pixy's receive queue. But that's all OK because 
+     // we normally only update the LED once per frame anyway.
+     delay(20);
+     
+     i++;
+   }
+}
+
+

lib/pixy/examples/pantilt/pantilt.ino

@@ -0,0 +1,119 @@
+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This sketch is a simple tracking demo that uses the pan/tilt unit.  For
+// more information, go here:
+//
+// http://cmucam.org/projects/cmucam5/wiki/Run_the_Pantilt_Demo
+//
+
+#include <SPI.h>  
+#include <Pixy.h>
+
+Pixy pixy;
+
+#define X_CENTER        ((PIXY_MAX_X-PIXY_MIN_X)/2)       
+#define Y_CENTER        ((PIXY_MAX_Y-PIXY_MIN_Y)/2)
+
+class ServoLoop
+{
+public:
+  ServoLoop(int32_t pgain, int32_t dgain);
+
+  void update(int32_t error);
+   
+  int32_t m_pos;
+  int32_t m_prevError;
+  int32_t m_pgain;
+  int32_t m_dgain;
+};
+
+
+ServoLoop panLoop(300, 500);
+ServoLoop tiltLoop(500, 700);
+
+ServoLoop::ServoLoop(int32_t pgain, int32_t dgain)
+{
+  m_pos = PIXY_RCS_CENTER_POS;
+  m_pgain = pgain;
+  m_dgain = dgain;
+  m_prevError = 0x80000000L;
+}
+
+void ServoLoop::update(int32_t error)
+{
+  long int vel;
+  char buf[32];
+  if (m_prevError!=0x80000000)
+  {	
+    vel = (error*m_pgain + (error - m_prevError)*m_dgain)>>10;
+    //sprintf(buf, "%ld\n", vel);
+    //Serial.print(buf);
+    m_pos += vel;
+    if (m_pos>PIXY_RCS_MAX_POS) 
+      m_pos = PIXY_RCS_MAX_POS; 
+    else if (m_pos<PIXY_RCS_MIN_POS) 
+      m_pos = PIXY_RCS_MIN_POS;
+  }
+  m_prevError = error;
+}
+
+
+
+void setup()
+{
+  Serial.begin(9600);
+  Serial.print("Starting...\n");
+  
+  pixy.init();
+}
+
+void loop()
+{ 
+  static int i = 0;
+  int j;
+  uint16_t blocks;
+  char buf[32]; 
+  int32_t panError, tiltError;
+  
+  blocks = pixy.getBlocks();
+  
+  if (blocks)
+  {
+    panError = X_CENTER-pixy.blocks[0].x;
+    tiltError = pixy.blocks[0].y-Y_CENTER;
+    
+    panLoop.update(panError);
+    tiltLoop.update(tiltError);
+    
+    pixy.setServos(panLoop.m_pos, tiltLoop.m_pos);
+    
+    i++;
+    
+    // do this (print) every 50 frames because printing every
+    // frame would bog down the Arduino
+    if (i%50==0) 
+    {
+      sprintf(buf, "Detected %d:\n", blocks);
+      Serial.print(buf);
+      for (j=0; j<blocks; j++)
+      {
+        sprintf(buf, "  block %d: ", j);
+        Serial.print(buf); 
+        pixy.blocks[j].print();
+      }
+    }
+  }  
+}
+

lib/pixy/examples/servo_move/servo_move.ino

@@ -0,0 +1,44 @@
+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This sketch is demonstrates the setServos() function.  Running this sketch
+// will move the servos to their limits, back and forth, back and forth. 
+//
+
+#include <SPI.h>  
+#include <Pixy.h>
+
+Pixy pixy;
+
+void setup()
+{
+
+  Serial.begin(9600);
+  Serial.print("Starting...\n");
+
+  pixy.init();
+}
+
+void loop() 
+{ 
+  Serial.println("Moving pan-tilt to max positions");
+  pixy.setServos(PIXY_RCS_MAX_POS, PIXY_RCS_MAX_POS);
+  delay(1000);
+
+  Serial.println("Moving pan-tilt to min positions");
+  pixy.setServos(PIXY_RCS_MIN_POS, PIXY_RCS_MIN_POS);
+  delay(1000);
+}
+
+

lib/pixy/examples/uart/uart.ino

@@ -0,0 +1,66 @@
+//
+// begin license header
+//
+// This file is part of Pixy CMUcam5 or "Pixy" for short
+//
+// All Pixy source code is provided under the terms of the
+// GNU General Public License v2 (http://www.gnu.org/licenses/gpl-2.0.html).
+// Those wishing to use Pixy source code, software and/or
+// technologies under different licensing terms should contact us at
+// cmucam@cs.cmu.edu. Such licensing terms are available for
+// all portions of the Pixy codebase presented here.
+//
+// end license header
+//
+// This sketch is like hello_world but uses UART communications.  If you're
+// not sure what UART is, run the hello_world sketch!
+//
+// Note, the default baudrate for Pixy's UART communications is 19200.  Given 
+// the slow datarate and Arduino's shallow serial FIFO, this sletch sometimes
+// gets checksum errors, when more than 1 block is present.  This is because
+// printing more than 1 object block to the serial console (as this sketch does) 
+// causes the Arduino's serial FIFO to overrun, which leads to communication 
+// errors.  
+//
+
+#include "PixyUART.h"
+
+
+PixyUART pixy;
+
+void setup()
+{
+  Serial.begin(9600); // 9600 baud for the serial *console* (not for the UART connected to Pixy)
+  Serial.print("Starting...\n");
+  
+  pixy.init();
+}
+
+void loop()
+{
+  static int i = 0;
+  int j;
+  uint16_t blocks;
+  char buf[32]; 
+  
+  blocks = pixy.getBlocks();
+  
+  if (blocks)
+  {
+    i++;
+    
+   // do this (print) every 50 frames because printing every
+   // frame would bog down the Arduino
+   if (i%50==0)
+    {
+      sprintf(buf, "Detected %d:\n", blocks);
+      Serial.print(buf);
+      for (j=0; j<blocks; j++)
+      {
+        sprintf(buf, "  block %d: ", j);
+        Serial.print(buf); 
+        pixy.blocks[j].print();
+      }
+    }
+  }  
+}

lib/pixy/keywords.txt

@@ -0,0 +1,11 @@
+Pixy	KEYWORD1
+PixyI2C	KEYWORD1
+PixyUART	KEYWORD1
+PixySPI_SS	KEYWORD1
+Block	KEYWORD1
+getBlocks	KEYWORD2
+init	KEYWORD2
+print	KEYWORD2
+setServos	KEYWORD2
+setBrightness	KEYWORD2
+setLED	KEYWORD2