Pixy2UART.h
//
// 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
//
// Arduino UART link class, intended to be used with an Arduino with more than 1 UART, 
// like the Arduino MEGA 2560.  

#ifndef _PIXY2UART_H
#define _PIXY2UART_H

#include "TPixy2.h"
#include "Arduino.h"

#define PIXY_UART_BAUDRATE        19200

class Link2UART
{
public:
  int8_t open(uint32_t arg)
  {
	if (arg==PIXY_DEFAULT_ARGVAL)
      Serial1.begin(PIXY_UART_BAUDRATE);
    else
      Serial1.begin(arg);      
    return 0;
  }
	
  void close()
  {
  }
    
  int16_t recv(uint8_t *buf, uint8_t len, uint16_t *cs=NULL)
  {
    uint8_t i, j;
	int16_t c;
    if (cs)
      *cs = 0;
    for (i=0; i<len; i++)
    {
      // wait for byte, timeout after 2ms
	  // note for a baudrate of 19.2K, each byte takes about 500us
      for (j=0; true; j++)
      {
        if (j==200)
          return -1;
	    c = Serial1.read();
        if (c>=0)
          break;
        delayMicroseconds(10);
      }
      buf[i] = c; 

      if (cs)
        *cs += buf[i];
    }
    return len;
  }
    
  int16_t send(uint8_t *buf, uint8_t len)
  {
    Serial1.write(buf, len);
    return len;
  }
  	
private:
  uint8_t m_addr;	
};


typedef TPixy2<Link2UART> Pixy2UART;

#endif