source: rtos_arduino/trunk/arduino_lib/hardware/arduino/samd/libraries/Wire/Wire.h@ 136

/*
 * TwoWire.h - TWI/I2C library for Arduino Due
 * Copyright (c) 2011 Cristian Maglie <c.maglie@bug.st>.
 * All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef TwoWire_h
#define TwoWire_h

//#include <include/twi.h>

#include "Stream.h"
#include "variant.h"

#include "SERCOM.h"
#include "RingBuffer.h"

#define BUFFER_LENGTH 32


class TwoWire : public Stream
{
        public:
                TwoWire(SERCOM *s);
                void begin();
                void begin(uint8_t);

                void beginTransmission(uint8_t);
                uint8_t endTransmission(bool stopBit);
                uint8_t endTransmission(void);

                uint8_t requestFrom(uint8_t address, size_t quantity, bool stopBit);
                uint8_t requestFrom(uint8_t address, size_t quantity);

                size_t write(uint8_t data);
                size_t write(const uint8_t * data, size_t quantity);

                virtual int available(void);
                virtual int read(void);
                virtual int peek(void);
                virtual void flush(void);
                void onReceive(void(*)(int));
                void onRequest(void(*)(void));

                using Print::write;

                void onService(void);

        private:
                SERCOM * sercom;
                bool transmissionBegun;

                // RX Buffer
                RingBuffer rxBuffer;

                //TX buffer
                RingBuffer txBuffer;
                uint8_t txAddress;


                // Service buffer
                //uint8_t srvBuffer[BUFFER_LENGTH];
                //uint8_t srvBufferIndex;
                //uint8_t srvBufferLength;

                // Callback user functions
                void (*onRequestCallback)(void);
                void (*onReceiveCallback)(int);

                // TWI state
                //enum TwoWireStatus
    //{
                //      UNINITIALIZED,
                //      MASTER_IDLE,
                //      MASTER_SEND,
                //      MASTER_RECV,
                //      SLAVE_IDLE,
                //      SLAVE_RECV,
                //      SLAVE_SEND
                //};
                //TwoWireStatus status;

                // TWI clock frequency
                static const uint32_t TWI_CLOCK = 100000;

                // Timeouts
                //static const uint32_t RECV_TIMEOUT = 100000;
                //static const uint32_t XMIT_TIMEOUT = 100000;
};

extern TwoWire Wire;

#endif