libraries/Wire/Wire.h

/*
    TwoWire.h - TWI/I2C library for Arduino & Wiring
    Copyright (c) 2006 Nicholas Zambetti.  All right 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

    Modified 2012 by Todd Krein (todd@krein.org) to implement repeated starts
    Modified December 2014 by Ivan Grokhotkov (ivan@esp8266.com) - esp8266 support
    Modified April 2015 by Hrsto Gochkov (ficeto@ficeto.com) - alternative esp8266 support
*/

#ifndef TwoWire_h
#define TwoWire_h

#include <inttypes.h>
#include "Stream.h"

#ifndef I2C_BUFFER_LENGTH
// DEPRECATED: Do not use BUFFER_LENGTH, prefer I2C_BUFFER_LENGTH
#define BUFFER_LENGTH 128
#define I2C_BUFFER_LENGTH BUFFER_LENGTH
#endif

class TwoWire: public Stream
{
private:
    static uint8_t rxBuffer[];
    static size_t  rxBufferIndex;
    static size_t  rxBufferLength;

    static uint8_t txAddress;
    static uint8_t txBuffer[];
    static size_t  txBufferIndex;
    static size_t  txBufferLength;

    static uint8_t transmitting;
    static void (*user_onRequest)(void);
    static void (*user_onReceive)(size_t);
    static void onRequestService(void);
    static void onReceiveService(uint8_t*, size_t);

public:
    TwoWire();
    void    begin(int sda, int scl);
    void    begin(int sda, int scl, uint8_t address);
    void    pins(int sda, int scl) __attribute__((deprecated));  // use begin(sda, scl) in new code
    void    begin();
    void    begin(uint8_t);
    void    begin(int);
    void    setClock(uint32_t);
    void    setClockStretchLimit(uint32_t);
    void    beginTransmission(uint8_t);
    void    beginTransmission(int);
    uint8_t endTransmission(void);
    uint8_t endTransmission(uint8_t);
    size_t  requestFrom(uint8_t address, size_t size, bool sendStop);
    uint8_t status();

    uint8_t requestFrom(uint8_t, uint8_t);
    uint8_t requestFrom(uint8_t, uint8_t, uint8_t);
    uint8_t requestFrom(int, int);
    uint8_t requestFrom(int, int, int);

    virtual size_t write(uint8_t);
    virtual size_t write(const uint8_t*, size_t);
    virtual int    available(void);
    virtual int    read(void);
    virtual int    peek(void);
    virtual void   flush(void);
    void           onReceive(void (*)(int));     // arduino api
    void           onReceive(void (*)(size_t));  // legacy esp8266 backward compatibility
    void           onRequest(void (*)(void));

    using Print::write;
};

#if !defined(NO_GLOBAL_INSTANCES) && !defined(NO_GLOBAL_TWOWIRE)
extern TwoWire Wire;
#endif

#endif