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@16:9b5a51117afe, 2014-09-02 (annotated)

Committer:
vtraveller
Date:
Tue Sep 02 07:11:53 2014 +0000
Revision:
16:9b5a51117afe
Parent:
15:164d420bcbcf 
Changed to use shared I2C interface object

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 12:6d9d2b277f26 3 Modified for use on the MBED ARM platform
jimherd 0:a6a5d942b58f 4
jimherd 0:a6a5d942b58f 5 This program is free software: you can redistribute it and/or modify
jimherd 0:a6a5d942b58f 6 it under the terms of the GNU General Public License as published by
jimherd 0:a6a5d942b58f 7 the Free Software Foundation, either version 3 of the License, or
jimherd 0:a6a5d942b58f 8 (at your option) any later version.
jimherd 0:a6a5d942b58f 9
jimherd 0:a6a5d942b58f 10 This program is distributed in the hope that it will be useful,
jimherd 0:a6a5d942b58f 11 but WITHOUT ANY WARRANTY; without even the implied warranty of
jimherd 0:a6a5d942b58f 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
jimherd 0:a6a5d942b58f 13 GNU General Public License for more details.
jimherd 0:a6a5d942b58f 14
jimherd 0:a6a5d942b58f 15 You should have received a copy of the GNU General Public License
jimherd 0:a6a5d942b58f 16 along with this program. If not, see <http://www.gnu.org/licenses/>.
jimherd 0:a6a5d942b58f 17 */
jimherd 0:a6a5d942b58f 18
jimherd 0:a6a5d942b58f 19 #ifndef MBED_MCP23017_H
jimherd 0:a6a5d942b58f 20 #define MBED_MCP23017_H
jimherd 0:a6a5d942b58f 21
jimherd 1:d54d7002bae2 22 #include "mbed.h"
jimherd 1:d54d7002bae2 23
jimherd 0:a6a5d942b58f 24 //
jimherd 0:a6a5d942b58f 25 // Register defines from data sheet - we set IOCON.BANK to 0
jimherd 0:a6a5d942b58f 26 // as it is easier to manage the registers sequentially.
jimherd 0:a6a5d942b58f 27 //
jimherd 0:a6a5d942b58f 28 #define IODIR 0x00
jimherd 0:a6a5d942b58f 29 #define IPOL 0x02
jimherd 0:a6a5d942b58f 30 #define GPINTEN 0x04
jimherd 0:a6a5d942b58f 31 #define DEFVAL 0x06
jimherd 0:a6a5d942b58f 32 #define INTCON 0x08
jimherd 0:a6a5d942b58f 33 #define IOCON 0x0A
jimherd 0:a6a5d942b58f 34 #define GPPU 0x0C
jimherd 0:a6a5d942b58f 35 #define INTF 0x0E
jimherd 0:a6a5d942b58f 36 #define INTCAP 0x10
jimherd 0:a6a5d942b58f 37 #define GPIO 0x12
jimherd 0:a6a5d942b58f 38 #define OLAT 0x14
jimherd 0:a6a5d942b58f 39
jimherd 0:a6a5d942b58f 40 #define I2C_BASE_ADDRESS 0x40
jimherd 0:a6a5d942b58f 41
jimherd 0:a6a5d942b58f 42 #define DIR_OUTPUT 0
jimherd 0:a6a5d942b58f 43 #define DIR_INPUT 1
jimherd 0:a6a5d942b58f 44
jimherd 11:8726c7be6d72 45 /** MCP23017 class
jimherd 11:8726c7be6d72 46 *
jimherd 13:d57de266cf19 47 * Allow access to an I2C connected MCP23017 16-bit I/O extender chip
jimherd 13:d57de266cf19 48 * Example:
jimherd 13:d57de266cf19 49 * @code
jimherd 13:d57de266cf19 50 * MCP23017 *par_port;
jimherd 13:d57de266cf19 51 * @endcode
jimherd 13:d57de266cf19 52 *
jimherd 11:8726c7be6d72 53 */
jimherd 0:a6a5d942b58f 54 class MCP23017 {
jimherd 0:a6a5d942b58f 55 public:
jimherd 0:a6a5d942b58f 56 /** Constructor for the MCP23017 connected to specified I2C pins at a specific address
jimherd 0:a6a5d942b58f 57 *
jimherd 0:a6a5d942b58f 58 * 16-bit I/O expander with I2C interface
jimherd 0:a6a5d942b58f 59 *
vtraveller 16:9b5a51117afe 60 * @param i2c I2C interface
jimherd 0:a6a5d942b58f 61 * @param i2cAddress I2C address
jimherd 0:a6a5d942b58f 62 */
vtraveller 16:9b5a51117afe 63 MCP23017(I2C & i2c, int i2cAddress);
jimherd 0:a6a5d942b58f 64
jimherd 0:a6a5d942b58f 65 /** Reset MCP23017 device to its power-on state
jimherd 0:a6a5d942b58f 66 */
jimherd 0:a6a5d942b58f 67 void reset(void);
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 value 0 or 1
jimherd 0:a6a5d942b58f 72 * @param bit_number bit number range 0 --> 15
jimherd 0:a6a5d942b58f 73 */
jimherd 0:a6a5d942b58f 74 void write_bit(int value, int bit_number);
jimherd 0:a6a5d942b58f 75
jimherd 10:a3b9eabb0e50 76 /** Write a masked 16-bit value to the device
jimherd 0:a6a5d942b58f 77 *
jimherd 0:a6a5d942b58f 78 * @param data 16-bit data value
jimherd 0:a6a5d942b58f 79 * @param mask 16-bit mask value
jimherd 0:a6a5d942b58f 80 */
jimherd 0:a6a5d942b58f 81 void write_mask(unsigned short data, unsigned short mask);
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 bit_number bit number range 0 --> 15
jimherd 0:a6a5d942b58f 86 * @return 0/1 value read
jimherd 0:a6a5d942b58f 87 */
jimherd 0:a6a5d942b58f 88 int read_bit(int bit_number);
jimherd 0:a6a5d942b58f 89
jimherd 10:a3b9eabb0e50 90 /** Read a 16-bit value from the device and apply mask
jimherd 0:a6a5d942b58f 91 *
jimherd 0:a6a5d942b58f 92 * @param mask 16-bit mask value
jimherd 0:a6a5d942b58f 93 * @return 16-bit data with mask applied
jimherd 0:a6a5d942b58f 94 */
jimherd 0:a6a5d942b58f 95 int read_mask(unsigned short mask);
jimherd 0:a6a5d942b58f 96
jimherd 0:a6a5d942b58f 97 /** Configure an MCP23017 device
jimherd 0:a6a5d942b58f 98 *
jimherd 0:a6a5d942b58f 99 * @param dir_config data direction value (1 = input, 0 = output)
jimherd 0:a6a5d942b58f 100 * @param pullup_config 100k pullup value (1 = enabled, 0 = disabled)
jimherd 0:a6a5d942b58f 101 * @param polarity_config polarity value (1 = flip, 0 = normal)
jimherd 0:a6a5d942b58f 102 */
jimherd 0:a6a5d942b58f 103 void config(unsigned short dir_config, unsigned short pullup_config, unsigned short polarity_config);
jimherd 0:a6a5d942b58f 104
jimherd 12:6d9d2b277f26 105 void writeRegister(int regAddress, unsigned char val);
jimherd 12:6d9d2b277f26 106 void writeRegister(int regAddress, unsigned short val);
jimherd 12:6d9d2b277f26 107 int readRegister(int regAddress);
jimherd 0:a6a5d942b58f 108
jimherd 12:6d9d2b277f26 109 /*-----------------------------------------------------------------------------
jimherd 0:a6a5d942b58f 110 * pinmode
jimherd 0:a6a5d942b58f 111 * Set units to sequential, bank0 mode
jimherd 0:a6a5d942b58f 112 */
jimherd 7:c282ea90cdb5 113 void pinMode(int pin, int mode);
jimherd 0:a6a5d942b58f 114 void digitalWrite(int pin, int val);
jimherd 0:a6a5d942b58f 115 int digitalRead(int pin);
jimherd 0:a6a5d942b58f 116
jimherd 0:a6a5d942b58f 117 // These provide a more advanced mapping of the chip functionality
jimherd 0:a6a5d942b58f 118 // See the data sheet for more information on what they do
jimherd 0:a6a5d942b58f 119
jimherd 0:a6a5d942b58f 120 //Returns a word with the current pin states (ie contents of the GPIO register)
jimherd 0:a6a5d942b58f 121 unsigned short digitalWordRead();
jimherd 0:a6a5d942b58f 122 // Allows you to write a word to the GPIO register
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 0:a6a5d942b58f 126 void inputPolarityMask(unsigned short mask);
jimherd 0:a6a5d942b58f 127 //Sets which pins are inputs or outputs (1 = input, 0 = output) NB Opposite to arduino's
jimherd 0:a6a5d942b58f 128 //definition for these
jimherd 0:a6a5d942b58f 129 void inputOutputMask(unsigned short mask);
jimherd 0:a6a5d942b58f 130 // Allows enabling of the internal 100k pullup resisters (1 = enabled, 0 = disabled)
jimherd 0:a6a5d942b58f 131 void internalPullupMask(unsigned short mask);
jimherd 0:a6a5d942b58f 132 int read(void);
jimherd 0:a6a5d942b58f 133 void write(int data);
jimherd 0:a6a5d942b58f 134
jimherd 0:a6a5d942b58f 135 protected:
vtraveller 16:9b5a51117afe 136 I2C & _i2c;
jimherd 0:a6a5d942b58f 137 int MCP23017_i2cAddress; // physical I2C address
jimherd 0:a6a5d942b58f 138 unsigned short shadow_GPIO, shadow_IODIR, shadow_GPPU, shadow_IPOL; // Cached copies of the register values
jimherd 0:a6a5d942b58f 139
jimherd 0:a6a5d942b58f 140 };
jimherd 0:a6a5d942b58f 141
vtraveller 16:9b5a51117afe 142 #endif