pcf8574.cpp

00001 /*
00002 * PCF8574(A) Remote 8-bit I/O expander for I2C-bus
00003 * Copyright (c) 2012 Bas van Drunen Littel
00004 *
00005 * Permission is hereby granted, free of charge, to any person obtaining a copy
00006 * of this software and associated documentation files (the "Software"), to deal
00007 * in the Software without restriction, including without limitation the rights
00008 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00009 * copies of the Software, and to permit persons to whom the Software is
00010 * furnished to do so, subject to the following conditions:
00011 *
00012 * The above copyright notice and this permission notice shall be included in
00013 * all copies or substantial portions of the Software.
00014 *
00015 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00016 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00017 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00018 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00019 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00020 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00021 * THE SOFTWARE.
00022 */
00023 
00024 #include "pcf8574.h"
00025 
00026 PCF8574::PCF8574(I2C* _interface, unsigned char _chipselect, bool _type)
00027     : i2c(_interface)
00028 {
00029     if (_type == PCF8574_TYPE) {
00030         address = (_chipselect << 1) | PCF8574_I2C_ADDRESS;
00031     } else {
00032         address = (_chipselect << 1) | PCF8574A_I2C_ADDRESS;
00033     }
00034 }
00035 
00036 PCF8574::~PCF8574() {}
00037 
00038 unsigned char PCF8574::ReadByte()
00039 {
00040     char data[1];
00041     i2c->read(address,data,1);
00042     return data[0];
00043 }
00044 
00045 void PCF8574::WriteByte(unsigned char byte)
00046 {
00047     unsigned char data[1];
00048     
00049     data[0]=byte;
00050     i2c->write(address,(char *)data,1);
00051 }