Takuya Urakawa / MCP23017

Simple MCP23017 I2C 16bit IO expander IC

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MCP23017 Class Reference
Public Member Functions

MCP23017 Class Reference

MCP23017 class. More...

#include <MCP23017.h>

Public Member Functions

 MCP23017 (I2C &_i2c, char _addr)
 Constructor.
void init (void)
 Software Reset.
void setConfig (char _value)
 Configure MCP23017 Write IOCON register See MCP23017 datasheet p18 http://ww1.microchip.com/downloads/jp/DeviceDoc/21952b.pdf.
void setDirrection (char _port, char _value)
 Set I/O dirrection.
void setPullUp (char _port, char _value)
 Set pullup.
void setInputPolarity (char _port, char _value)
 Set Input Polarity.
void write (char _port, char _value)
 Write GPIO.
char read (char _port)
 Read GPIO.

Detailed Description

MCP23017 class.

Allow access MCP23017 I2C 16bit io expander IC But this library can not controll interrupt functions

Example: 

  #include "mbed.h"
  #include "MCP23017.h"

  I2C i2c(dp5, dp27); // LPC1114
  MCP23017::MCP23017 io(&i2c,MCP23017_DEFAULT_ADDR);

  int main(void)
  { 
      i2c.frequency(400000);
    
      // software reset
      io.init();
    
      io.setDirrection(MCP23017_PORTA, 0xFF);    // set all of the PORTA pins to input
      io.setDirrection(MCP23017_PORTB, 0x00);    // set all of the PORTB pins to output
      io.setPullUp(MCP23017_PORTA, 0xFF);        // activate all of the PORTA pin pull-ups
      io.setInputPolarity(MCP23017_PORTA, 0xFF); // invert all of the PORTA pins input polarity

    while(true){
        // write PORTA to PORTB
    io.write(1,io.read(0));
      }

      return 0;
  }

Definition at line 54 of file MCP23017.h.

Constructor & Destructor Documentation

MCP23017 ( I2C &  _i2c,
char  _addr 
)

Constructor.

Parameters:
_i2cpointer to I2C class
_addri2c device address

Definition at line 12 of file MCP23017.cpp.

Member Function Documentation

void init ( void   )

Software Reset.

Definition at line 19 of file MCP23017.cpp.

char read ( char  _port )

Read GPIO.

Parameters:
_portport(MCP23017_PORTA or MCP23017_PORTB)
Returns:
byte

Definition at line 64 of file MCP23017.cpp.

void setConfig ( char  _value )

Configure MCP23017 Write IOCON register See MCP23017 datasheet p18 http://ww1.microchip.com/downloads/jp/DeviceDoc/21952b.pdf.

Attention:
BANK bit must set 0
Parameters:
_valuewrite byte

Definition at line 38 of file MCP23017.cpp.

void setDirrection ( char  _port,
char  _value 
)

Set I/O dirrection.

Parameters:
_portport(MCP23017_PORTA or MCP23017_PORTB)
_valuewrite byte(0=OUTPUT, 1=INPUT)

Definition at line 43 of file MCP23017.cpp.

void setInputPolarity ( char  _port,
char  _value 
)

Set Input Polarity.

Parameters:
_portport(MCP23017_PORTA or MCP23017_PORTB)
_valuewrite byte (0=normal, 1=inverted)

Definition at line 53 of file MCP23017.cpp.

void setPullUp ( char  _port,
char  _value 
)

Set pullup.

Parameters:
_portport (MCP23017_PORTA or MCP23017_PORTB)
_valuewrite byte (0=Disable, 1=Enable)

Definition at line 48 of file MCP23017.cpp.

void write ( char  _port,
char  _value 
)

Write GPIO.

Parameters:
_portport(MCP23017_PORTA or MCP23017_PORTB)
_valuewrite byte

Definition at line 59 of file MCP23017.cpp.

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