PCF8574.h

#pragma once
//
//    FILE: PCF8574.h
//  AUTHOR: Rob Tillaart
//    DATE: 02-febr-2013
// VERSION: 0.4.1
// PURPOSE: Arduino library for PCF8574 - 8 channel I2C IO expander
//     URL: https://github.com/RobTillaart/PCF8574
//          http://forum.arduino.cc/index.php?topic=184800


#include "Arduino.h"
#include "Wire.h"


#define PCF8574_LIB_VERSION         (F("0.4.1"))

#ifndef PCF8574_INITIAL_VALUE
#define PCF8574_INITIAL_VALUE       0xFF
#endif

#define PCF8574_OK                  0x00
#define PCF8574_PIN_ERROR           0x81
#define PCF8574_I2C_ERROR           0x82


class PCF8574
{
public:
  explicit PCF8574(const uint8_t deviceAddress = 0x20, TwoWire *wire = &Wire);

  bool    begin(uint8_t value = PCF8574_INITIAL_VALUE);
  bool    isConnected();


  //  note: setting the address corrupt internal buffer values
  //  a read8() / write8() call updates them.
  bool    setAddress(const uint8_t deviceAddress);
  uint8_t getAddress();


  uint8_t read8();
  uint8_t read(const uint8_t pin);
  uint8_t value() const { return _dataIn; };


  void    write8(const uint8_t value);
  void    write(const uint8_t pin, const uint8_t value);
  uint8_t valueOut() const { return _dataOut; }


  //  added 0.1.07/08 Septillion
  uint8_t readButton8() { return PCF8574::readButton8(_buttonMask); }
  uint8_t readButton8(const uint8_t mask);
  uint8_t readButton(const uint8_t pin);
  void    setButtonMask(const uint8_t mask) { _buttonMask = mask; };
  uint8_t getButtonMask() { return _buttonMask; };


  //  rotate, shift, toggle, reverse expect all lines are output
  void    toggle(const uint8_t pin);
  //      default 0xFF ==> invertAll()
  void    toggleMask(const uint8_t mask = 0xFF);
  void    shiftRight(const uint8_t n = 1);
  void    shiftLeft(const uint8_t n = 1);
  void    rotateRight(const uint8_t n = 1);
  void    rotateLeft(const uint8_t n = 1);
  void    reverse();


  void    select(const uint8_t pin);
  void    selectN(const uint8_t pin);
  void    selectNone() { write8(0x00); };
  void    selectAll()  { write8(0xFF); };


  int     lastError();


private:
  uint8_t _address;
  uint8_t _dataIn;
  uint8_t _dataOut;
  uint8_t _buttonMask;
  int     _error;

  TwoWire*  _wire;
};


//  -- END OF FILE --