File content as of revision 43:aff670d0d510:

/* mbed Microcontroller Library - I2C
 * Copyright (c) 2007-2011 ARM Limited. All rights reserved.
 */ 
 
#ifndef MBED_I2C_H
#define MBED_I2C_H

#include "device.h"

#if DEVICE_I2C

#include "platform.h"
#include "PinNames.h"
#include "PeripheralNames.h"
#include "Base.h"

namespace mbed {

/** An I2C Master, used for communicating with I2C slave devices
 *
 * Example:
 * @code
 * // Read from I2C slave at address 0x62
 *
 * #include "mbed.h"
 *
 * I2C i2c(p28, p27);
 *
 * int main() {
 *     int address = 0x62;
 *     char data[2];
 *     i2c.read(address, data, 2);
 * }
 * @endcode
 */
class I2C : public Base {

public:

    enum RxStatus {
        NoData
        , MasterGeneralCall
        , MasterWrite
        , MasterRead
    };

    enum Acknowledge {
          NoACK = 0
        , ACK   = 1
    };

    /** Create an I2C Master interface, connected to the specified pins
     *
     *  @param sda I2C data line pin
     *  @param scl I2C clock line pin
     */
    I2C(PinName sda, PinName scl, const char *name = NULL);

    /** Set the frequency of the I2C interface
     *
     *  @param hz The bus frequency in hertz
     */
    void frequency(int hz);

    /** Read from an I2C slave
     *
     *  Performs a complete read transaction. The bottom bit of
     *  the address is forced to 1 to indicate a read.
     *
     *  @param address 8-bit I2C slave address [ addr | 1 ]
     *  @param data Pointer to the byte-array to read data in to 
     *  @param length Number of bytes to read
     *  @param repeated Repeated start, true - don't send stop at end
     *
     *  @returns
     *       0 on success (ack),
     *   non-0 on failure (nack)
     */ 
    int read(int address, char *data, int length, bool repeated = false); 

    /** Read a single byte from the I2C bus
     *
     *  @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
     *
     *  @returns
     *    the byte read
     */
    int read(int ack);

    /** Write to an I2C slave
     *
     *  Performs a complete write transaction. The bottom bit of
     *  the address is forced to 0 to indicate a write.
     *
     *  @param address 8-bit I2C slave address [ addr | 0 ]
     *  @param data Pointer to the byte-array data to send 
     *  @param length Number of bytes to send
     *  @param repeated Repeated start, true - do not send stop at end
     *
     *  @returns
     *       0 on success (ack),
     *   non-0 on failure (nack)
     */ 
    int write(int address, const char *data, int length, bool repeated = false);

    /** Write single byte out on the I2C bus
     *
     *  @param data data to write out on bus
     *
     *  @returns
     *    '1' if an ACK was received,
     *    '0' otherwise
     */
    int write(int data);

    /** Creates a start condition on the I2C bus
     */
    void start(void);

    /** Creates a stop condition on the I2C bus
     */
    void stop(void);

protected:

    void aquire();

    I2CName     _i2c;
    static I2C  *_owner;
    int         _hz;

};

} // namespace mbed

#endif

#endif