Modified I2C api to work with NRF's dynamic pin asignment.

Dependents:   Seed_Barometer_Sensor_custom_I2C_lib

Note that the only changes are in the constructor. I tried extending the original I2C class, but could not find away to avoid the i2c_init from being called there.

I2CX.h

Committer:
jaerts
Date:
2014-10-22
Revision:
2:9d9fc94594e3
Parent:
1:6e73259cca6e

File content as of revision 2:9d9fc94594e3:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2013 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef MBED_I2CX_H
#define MBED_I2CX_H

#include "platform.h"

#if DEVICE_I2C

#include "i2c_api.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"
 * #include "I2CX.h"
 *  
 * I2CX i2c(I2C_0, p28, p27);
 *  
 * int main() {
 *     int address = 0x62;
 *     char data[2];
 *     i2c.read(address, data, 2);
 * }
 * @endcode
 */
class I2CX {

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

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

    /** Create an I2CX Master interface, connected to the specified pins
     *
     *  @param sda I2CX data line pin
     *  @param scl I2CX clock line pin
     */
    I2CX(I2CName peripheral, PinName sda, PinName scl);

    /** Set the frequency of the I2CX interface
     *
     *  @param hz The bus frequency in hertz
     */
    void frequency(int hz);

    /** Read from an I2CX slave
     *
     * Performs a complete read transaction. The bottom bit of
     * the address is forced to 1 to indicate a read.
     *
     *  @param address 8-bit I2CX 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 I2CX bus
     *
     *  @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
     *
     *  @returns
     *    the byte read
     */
    int read(int ack);

    /** Write to an I2CX slave
     *
     * Performs a complete write transaction. The bottom bit of
     * the address is forced to 0 to indicate a write.
     *
     *  @param address 8-bit I2CX 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 I2CX 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 I2CX bus
     */

    void start(void);

    /** Creates a stop condition on the I2CX bus
     */
    void stop(void);

protected:
    void aquire();

    i2c_t _i2c;
    static I2CX  *_owner;
    int         _hz;
};

} // namespace mbed

#endif

#endif