Justin Howard / MCP23017

Basic library of routines to interface to a Microchip MCP23017 16-bit I/O expander using an I2C interface.

Dependents:   AdaFruit_RGBLCD SX1276_GPS

Fork of MCP23017 by jim herd

MCP23017.h@3:f00ee94327c6, 2010-11-28 (annotated)

Committer:
jimherd
Date:
Sun Nov 28 21:21:17 2010 +0000
Revision:
3:f00ee94327c6
Parent:
1:d54d7002bae2
Child:
4:32fd6ee97dff

        

        
Who changed what in which revision?

        

            
                
UserRevisionLine numberNew contents of line

            
            


jimherd

0:a6a5d942b58f


     1

/*  MCP23017 library for Arduino





jimherd

0:a6a5d942b58f


     2

    Copyright (C) 2009 David Pye    <davidmpye@gmail.com





jimherd

0:a6a5d942b58f


     3







jimherd

0:a6a5d942b58f


     4

    This program is free software: you can redistribute it and/or modify





jimherd

0:a6a5d942b58f


     5

    it under the terms of the GNU General Public License as published by





jimherd

0:a6a5d942b58f


     6

    the Free Software Foundation, either version 3 of the License, or





jimherd

0:a6a5d942b58f


     7

    (at your option) any later version.





jimherd

0:a6a5d942b58f


     8







jimherd

0:a6a5d942b58f


     9

    This program is distributed in the hope that it will be useful,





jimherd

0:a6a5d942b58f


    10

    but WITHOUT ANY WARRANTY; without even the implied warranty of





jimherd

0:a6a5d942b58f


    11

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the





jimherd

0:a6a5d942b58f


    12

    GNU General Public License for more details.





jimherd

0:a6a5d942b58f


    13







jimherd

0:a6a5d942b58f


    14

    You should have received a copy of the GNU General Public License





jimherd

0:a6a5d942b58f


    15

    along with this program.  If not, see <http://www.gnu.org/licenses/>.





jimherd

0:a6a5d942b58f


    16

*/





jimherd

0:a6a5d942b58f


    17







jimherd

0:a6a5d942b58f


    18

#ifndef     MBED_MCP23017_H





jimherd

0:a6a5d942b58f


    19

#define     MBED_MCP23017_H





jimherd

0:a6a5d942b58f


    20







jimherd

1:d54d7002bae2


    21

#include    "mbed.h"





jimherd

1:d54d7002bae2


    22







jimherd

1:d54d7002bae2


    23

/** MCP23017 class





jimherd

1:d54d7002bae2


    24

 */





jimherd

0:a6a5d942b58f


    25

//





jimherd

0:a6a5d942b58f


    26

// Register defines from data sheet - we set IOCON.BANK to 0





jimherd

0:a6a5d942b58f


    27

// as it is easier to manage the registers sequentially.





jimherd

0:a6a5d942b58f


    28

//





jimherd

0:a6a5d942b58f


    29

#define     IODIR       0x00





jimherd

0:a6a5d942b58f


    30

#define     IPOL        0x02





jimherd

0:a6a5d942b58f


    31

#define     GPINTEN     0x04





jimherd

0:a6a5d942b58f


    32

#define     DEFVAL      0x06





jimherd

0:a6a5d942b58f


    33

#define     INTCON      0x08





jimherd

0:a6a5d942b58f


    34

#define     IOCON       0x0A





jimherd

0:a6a5d942b58f


    35

#define     GPPU        0x0C





jimherd

0:a6a5d942b58f


    36

#define     INTF        0x0E





jimherd

0:a6a5d942b58f


    37

#define     INTCAP      0x10





jimherd

0:a6a5d942b58f


    38

#define     GPIO        0x12





jimherd

0:a6a5d942b58f


    39

#define     OLAT        0x14





jimherd

0:a6a5d942b58f


    40







jimherd

0:a6a5d942b58f


    41

#define     I2C_BASE_ADDRESS    0x40





jimherd

0:a6a5d942b58f


    42







jimherd

0:a6a5d942b58f


    43

#define     DIR_OUTPUT      0





jimherd

0:a6a5d942b58f


    44

#define     DIR_INPUT       1





jimherd

0:a6a5d942b58f


    45







jimherd

0:a6a5d942b58f


    46

class MCP23017 {





jimherd

0:a6a5d942b58f


    47

public:





jimherd

0:a6a5d942b58f


    48

    /** Constructor for the MCP23017 connected to specified I2C pins at a specific address





jimherd

0:a6a5d942b58f


    49

     *





jimherd

0:a6a5d942b58f


    50

     * 16-bit I/O expander with I2C interface





jimherd

0:a6a5d942b58f


    51

     *





jimherd

0:a6a5d942b58f


    52

     * @param   sda         I2C data pin





jimherd

0:a6a5d942b58f


    53

     * @param   scl         I2C clock pin





jimherd

0:a6a5d942b58f


    54

     * @param   i2cAddress  I2C address





jimherd

0:a6a5d942b58f


    55

     */





jimherd

0:a6a5d942b58f


    56

    MCP23017(PinName sda, PinName scl, int i2cAddress);





jimherd

0:a6a5d942b58f


    57







jimherd

0:a6a5d942b58f


    58

    /** Reset MCP23017 device to its power-on state





jimherd

0:a6a5d942b58f


    59

     */    





jimherd

0:a6a5d942b58f


    60

    void reset(void);





jimherd

0:a6a5d942b58f


    61







jimherd

0:a6a5d942b58f


    62

    /** Write a 0/1 value to an output bit





jimherd

0:a6a5d942b58f


    63

     *





jimherd

0:a6a5d942b58f


    64

     * @param   value         0 or 1





jimherd

0:a6a5d942b58f


    65

     * @param   bit_number    bit number range 0 --> 15





jimherd

0:a6a5d942b58f


    66

     */   





jimherd

0:a6a5d942b58f


    67

    void write_bit(int value, int bit_number);





jimherd

0:a6a5d942b58f


    68

      





jimherd

0:a6a5d942b58f


    69

    /** Write a 0/1 value to an output bit





jimherd

0:a6a5d942b58f


    70

     *





jimherd

0:a6a5d942b58f


    71

     * @param   data    16-bit data value





jimherd

0:a6a5d942b58f


    72

     * @param   mask    16-bit mask value





jimherd

0:a6a5d942b58f


    73

     */       





jimherd

0:a6a5d942b58f


    74

    void write_mask(unsigned short data, unsigned short mask);





jimherd

0:a6a5d942b58f


    75







jimherd

0:a6a5d942b58f


    76

    /** Read a 0/1 value from an input bit





jimherd

0:a6a5d942b58f


    77

     *





jimherd

0:a6a5d942b58f


    78

     * @param   bit_number    bit number range 0 --> 15





jimherd

0:a6a5d942b58f


    79

     * @return                0/1 value read





jimherd

0:a6a5d942b58f


    80

     */       





jimherd

0:a6a5d942b58f


    81

    int  read_bit(int bit_number);





jimherd

0:a6a5d942b58f


    82

    





jimherd

0:a6a5d942b58f


    83

    /** Read a 0/1 value from an input bit





jimherd

0:a6a5d942b58f


    84

     *





jimherd

0:a6a5d942b58f


    85

     * @param   mask    16-bit mask value





jimherd

0:a6a5d942b58f


    86

     * @return          16-bit data with mask applied





jimherd

0:a6a5d942b58f


    87

     */     





jimherd

0:a6a5d942b58f


    88

    int  read_mask(unsigned short mask);





jimherd

0:a6a5d942b58f


    89







jimherd

0:a6a5d942b58f


    90

    /** Configure an MCP23017 device





jimherd

0:a6a5d942b58f


    91

     *





jimherd

0:a6a5d942b58f


    92

     * @param   dir_config         data direction value (1 = input, 0 = output)





jimherd

0:a6a5d942b58f


    93

     * @param   pullup_config      100k pullup value (1 = enabled, 0 = disabled)





jimherd

0:a6a5d942b58f


    94

     * @param   polarity_config    polarity value (1 = flip, 0 = normal)





jimherd

0:a6a5d942b58f


    95

     */           





jimherd

0:a6a5d942b58f


    96

    void config(unsigned short dir_config, unsigned short pullup_config, unsigned short polarity_config);





jimherd

0:a6a5d942b58f


    97







jimherd

0:a6a5d942b58f


    98







jimherd

0:a6a5d942b58f


    99

/*******************************************************************************





jimherd

0:a6a5d942b58f


   100

 * pinmode





jimherd

0:a6a5d942b58f


   101

 * Set units to sequential, bank0 mode





jimherd

0:a6a5d942b58f


   102

 */  





jimherd

3:f00ee94327c6


   103

    /**





jimherd

3:f00ee94327c6


   104

     */





jimherd

0:a6a5d942b58f


   105

    void pinMode(int pin, int mode);





jimherd

3:f00ee94327c6


   106

    /**





jimherd

3:f00ee94327c6


   107

     */    





jimherd

0:a6a5d942b58f


   108

    void digitalWrite(int pin, int val);





jimherd

3:f00ee94327c6


   109

    /**





jimherd

3:f00ee94327c6


   110

     */    





jimherd

0:a6a5d942b58f


   111

    int  digitalRead(int pin);





jimherd

0:a6a5d942b58f


   112







jimherd

0:a6a5d942b58f


   113

// These provide a more advanced mapping of the chip functionality





jimherd

0:a6a5d942b58f


   114

// See the data sheet for more information on what they do





jimherd

0:a6a5d942b58f


   115







jimherd

0:a6a5d942b58f


   116

//Returns a word with the current pin states (ie contents of the GPIO register)





jimherd

3:f00ee94327c6


   117

    /**





jimherd

3:f00ee94327c6


   118

     */





jimherd

0:a6a5d942b58f


   119

    unsigned short digitalWordRead();





jimherd

0:a6a5d942b58f


   120

// Allows you to write a word to the GPIO register





jimherd

3:f00ee94327c6


   121

    /**





jimherd

3:f00ee94327c6


   122

     */





jimherd

0:a6a5d942b58f


   123

    void digitalWordWrite(unsigned short w);





jimherd

0:a6a5d942b58f


   124

// Sets up the polarity mask that the MCP23017 supports





jimherd

0:a6a5d942b58f


   125

// if set to 1, it will flip the actual pin value.





jimherd

3:f00ee94327c6


   126

    /**





jimherd

3:f00ee94327c6


   127

     */





jimherd

0:a6a5d942b58f


   128

    void inputPolarityMask(unsigned short mask);





jimherd

0:a6a5d942b58f


   129

//Sets which pins are inputs or outputs (1 = input, 0 = output) NB Opposite to arduino's





jimherd

0:a6a5d942b58f


   130

//definition for these





jimherd

3:f00ee94327c6


   131

    /**





jimherd

3:f00ee94327c6


   132

     */





jimherd

0:a6a5d942b58f


   133

    void inputOutputMask(unsigned short mask);





jimherd

0:a6a5d942b58f


   134

// Allows enabling of the internal 100k pullup resisters (1 = enabled, 0 = disabled)





jimherd

3:f00ee94327c6


   135

    /**





jimherd

3:f00ee94327c6


   136

     */





jimherd

0:a6a5d942b58f


   137

    void internalPullupMask(unsigned short mask);





jimherd

3:f00ee94327c6


   138

    /**





jimherd

3:f00ee94327c6


   139

     */





jimherd

0:a6a5d942b58f


   140

    int read(void);





jimherd

3:f00ee94327c6


   141

    /**





jimherd

3:f00ee94327c6


   142

     */





jimherd

0:a6a5d942b58f


   143

    void write(int data);





jimherd

3:f00ee94327c6


   144

    /**





jimherd

3:f00ee94327c6


   145

     */    





jimherd

0:a6a5d942b58f


   146

    void writeRegister(int regAddress, unsigned char  val);





jimherd

3:f00ee94327c6


   147

    /**





jimherd

3:f00ee94327c6


   148

     */    





jimherd

0:a6a5d942b58f


   149

    void writeRegister(int regAddress, unsigned short val);





jimherd

3:f00ee94327c6


   150

    /**





jimherd

3:f00ee94327c6


   151

     */    





jimherd

0:a6a5d942b58f


   152

    int  readRegister(int regAddress);





jimherd

0:a6a5d942b58f


   153







jimherd

0:a6a5d942b58f


   154

protected:





jimherd

0:a6a5d942b58f


   155

    I2C     _i2c;





jimherd

0:a6a5d942b58f


   156

    int     MCP23017_i2cAddress;                        // physical I2C address





jimherd

0:a6a5d942b58f


   157

    unsigned short   shadow_GPIO, shadow_IODIR, shadow_GPPU, shadow_IPOL;     // Cached copies of the register values





jimherd

0:a6a5d942b58f


   158

    





jimherd

0:a6a5d942b58f


   159

};





jimherd

0:a6a5d942b58f


   160







jimherd

0:a6a5d942b58f


   161

#endif