PCF8574.h

00001 /* mbed PCF8574 Library, for driving the I2C I/O Expander
00002  * Copyright (c) 2008-2010, cstyles, sford
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00020  * THE SOFTWARE.
00021  */
00022 
00023 #include "mbed.h"
00024 
00025 #ifndef MBED_PCF8574_H
00026 #define MBED_PCF8574_H
00027 
00028 /** Interface to the popular PCF8574 I2C 8 Bit IO expander */
00029 class PCF8574 {
00030 public:
00031     /** Create an instance of the PCF8574 connected to specfied I2C pins, with the specified address.
00032      *
00033      * @param sda The I2C data pin
00034      * @param scl The I2C clock pin
00035      * @param address The I2C address for this PCF8574
00036      */
00037     PCF8574(PinName sda, PinName scl, int address);
00038 
00039     /** Read the IO pin level
00040      *
00041      * @return The byte read
00042      */
00043     int read();
00044     
00045     /** Write to the IO pins
00046      * 
00047      * @param data The 8 bits to write to the IO port
00048      */
00049     void write(int data);
00050 
00051 private:
00052     I2C _i2c;
00053     int _address;
00054 };
00055 
00056 #endif