MCP23017 Input/Output functions. More...

Data Structures
struct	_MCP23017

Macros
#define	MCP23017_REG_IODIRA 0x00

#define	MCP23017_REG_IODIRB 0x01

#define	MCP23017_REG_IPOLA 0x02

#define	MCP23017_REG_IPOLB 0x03

#define	MCP23017_REG_GPINTENA 0x04

#define	MCP23017_REG_GPINTENB 0x05

#define	MCP23017_REG_DEFVALA 0x06

#define	MCP23017_REG_DEFVALB 0x07

#define	MCP23017_REG_INTCONA 0x08

#define	MCP23017_REG_INTCONB 0x09

#define	MCP23017_REG_IOCON 0x0A

#define	MCP23017_REG_GPPUA 0x0C

#define	MCP23017_REG_GPPUB 0x0D

#define	MCP23017_REG_INTFA 0x0E

#define	MCP23017_REG_INTFB 0x0F

#define	MCP23017_REG_INTCAPA 0x10

#define	MCP23017_REG_INTCAPB 0x11

#define	MCP23017_REG_GPIOA 0x12

#define	MCP23017_REG_GPIOB 0x13

#define	MCP23017_REG_OLATA 0x14

#define	MCP23017_REG_OLATB 0x15

#define	MCP23017_ADDRESS 0x40 /Base address if A0 to A3 are all 0 /

#define	MCP23017_GPA0 0

#define	MCP23017_GPA1 1

#define	MCP23017_GPA2 2

#define	MCP23017_GPA3 3

#define	MCP23017_GPA4 4

#define	MCP23017_GPA5 5

#define	MCP23017_GPA6 6

#define	MCP23017_GPA7 7

#define	MCP23017_GPB0 8

#define	MCP23017_GPB1 9

#define	MCP23017_GPB2 10

#define	MCP23017_GPB3 11

#define	MCP23017_GPB4 12

#define	MCP23017_GPB5 13

#define	MCP23017_GPB6 14

#define	MCP23017_GPB7 15

#define	MCP23017_SETPIN 0x80

#define	MCP23017_CLEARPIN 0

#define	mcp23017_WritePin(obj, pin) mcp23017_WritePin(obj, pin \| 0x80)

#define	mcp23017_ClearPin(obj, pin) mcp23017_WritePin(obj, pin & 0x7f)

#define	mcp23017_ReadPins(obj) ((obj)->pin.Val)

Typedefs
typedef struct _MCP23017	MCP23017

Functions
INT8	mcp23017_Init (MCP23017 *obj)

INT8	mcp23017_ConfigDir (MCP23017 *obj, UINT16 dir)

INT8	mcp23017_ConfigDirMask (MCP23017 *obj, UINT16 dir, UINT16 mask)

INT8	mcp23017_ConfigPullups (MCP23017 *obj, UINT16 pullUps)

INT8	mcp23017_ConfigIntPins (MCP23017 *obj, UINT16 intPins)

INT8	mcp23017_WritePin (MCP23017 *obj, UINT8 pinVal)

INT8	mcp23017_WriteMask (MCP23017 *obj, UINT16 val, UINT16 mask)

INT8	mcp23017_ReadPins (MCP23017 *obj)

Detailed Description

MCP23017 Input/Output functions.

MCP23017 I/O Expander functions.

Author: Modtronix Engineering

Compiler:: MPLAB XC16 Compiler

Software License Agreement

The software supplied herewith is owned by Modtronix Engineering, and is protected under applicable copyright laws. The software supplied herewith is intended and supplied to you, the Company customer, for use solely and exclusively on products manufactured by Modtronix Engineering. The code may be modified and can be used free of charge for commercial and non commercial applications. All rights are reserved. Any use in violation of the foregoing restrictions may subject the user to criminal sanctions under applicable laws, as well as to civil liability for the breach of the terms and conditions of this license.

THIS SOFTWARE IS PROVIDED IN AN 'AS IS' CONDITION. NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. THE COMPANY SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.

File History

2011-06-03, David Hosken (DH):

Initial version

Author: Modtronix Engineering

Compiler:: MPLAB XC16 compiler

Description

Functions for using the MCP23017 I/O Expander

Configuration

The following defines are used to configure this module, and should be placed in projdefs.h. Note that all items marked [-DEFAULT-] are defaults, and do not have to be placed in projdefs.h if they contain desired configuration! For details, see Project Configuration.

// *********************************************************************
// -------------- MCP23017 Configuration --------------------
// *********************************************************************
//Uncomment one of the following, depending on what I2C bus should be used
#define MCP23017_USE_I2C1      //[-DEFAULT-] Use I2C Bus 1
//#define MCP23017_USE_I2C2    //Use I2C Bus 2
//#define MCP23017_USE_I2C3    //Use I2C Bus 3
//#define MCP23017_USE_I2C4    //Use I2C Bus 4

Macro Definition Documentation

#define mcp23017_ClearPin	(	obj,
		pin
	)	mcp23017_WritePin(obj, pin & 0x7f)

Clear a single pin. For example, to set pin GPA5, use command: mcp23017_ClearPin(0x40, MCP23017_GPA5)

Parameters

obj	Structure with data for MCP23017 chip
pin	Address of pin to clear. Is a value from 0 to 15. 0=GPA0, 7=GPA7 8=GPB0 and 15=GPB7

#define mcp23017_ReadPins ( obj) ((obj)->pin.Val)

Returns the current pin values saved in the MCP23017 object. The current pin values are NOT read from the MCP23017 chip. The mcp23017_ReadPins() will cause MCP23017 chip to be read. Use DINPTST1_IOX_MASK_XXX constants to test if pin is 0 or 1.

Parameters

obj	Pointer to structure with data for MCP23017 chip

Returns: Word with pin values in bits 0 to 15

#define mcp23017_WritePin	(	obj,
		pin
	)	mcp23017_WritePin(obj, pin \| 0x80)

Set a single pin. For example, to set pin GPA5, use command: mcp23017_WritePin(0x40, MCP23017_GPA5)

Parameters

obj	Structure with data for MCP23017 chip
pin	Address of pin to set. Is a value from 0 to 15. 0=GPA0, 7=GPA7 8=GPB0 and 15=GPB7

Typedef Documentation

typedef struct _MCP23017 MCP23017

Structure containing information for a MCP23017 chip. Can be multiple MCP23017 on a bus.

Function Documentation

INT8 mcp23017_ConfigDir	(	MCP23017 *	obj,
		UINT16	dir
	)

Configure direction of pins.

Parameters

obj	Structure with data for MCP23017 chip
dir	Direction bit for 16 port pins

Returns: Returns 0 if OK, else returns a non-zero value if error

Configure direction of pins.

Parameters

obj	Structure with data for MCP23017 chip
dir	Bits indicate direction of I/O pins. A 0 sets pin to output, and a 1 sets pin to input.

Returns: Returns 0 if OK, else returns a non-zero value if error

INT8 mcp23017_ConfigDirMask	(	MCP23017 *	obj,
		UINT16	dir,
		UINT16	mask
	)

Configure direction of pins. A mask and value is supplied.

Parameters

obj	Structure with data for MCP23017 chip
dir	Direction bit for 16 port pins
mask	16-bit mask

Returns: Returns 0 if OK, else returns a non-zero value if error

INT8 mcp23017_ConfigIntPins	(	MCP23017 *	obj,
		UINT16	intPins
	)

Configures what pins to use for interrupt-on-change function. If the value of any of these pins change, a interrupt will be generated.

Parameters

obj	Structure with data for MCP23017 chip
intPins	Bits indicate what pins to use for interrupt-on-change function

Returns: Returns 0 if OK, else returns a non-zero value if error

INT8 mcp23017_ConfigPullups	(	MCP23017 *	obj,
		UINT16	pullUps
	)

Configure pull-up resistors.

Parameters

obj	Structure with data for MCP23017 chip
pullUps	Bits indicate if pull-up's are active for 16 port pins

Returns: Returns 0 if OK, else returns a non-zero value if error

Configure pull-up resistors.

Parameters

obj	Structure with data for MCP23017 chip
pullUps	Bits indicate if pull-up is active.

Returns: Returns 0 if OK, else returns a non-zero value if error

INT8 mcp23017_Init ( MCP23017 * obj)

Initializes the MCP23017 I/O Expander

Pre-Condition:: The I2C port must have been initialized for Master Mode operation before calling this function!

Parameters

obj	Structure with data for MCP23017 chip

Returns: Returns 0 if OK, else returns a non-zero value if error

Initializes the MCP23017 I/O Expander

Pre-Condition:: The I2C port must have been initialized for Master Mode operation before calling this function!

Parameters

obj	Structure with data for MCP23017 chip.

Returns: Returns 0 if OK, else returns a non-zero value if error

INT8 mcp23017_ReadPins ( MCP23017 * obj)

Reads value of all pins, and updates obj->pin. This function does a read of the MCP23017 chip, and updates the pin value in the given MCP23017 object.

Parameters

obj	Pointer to structure with data for MCP23017 chip

Returns: 0 if all pins same as for last read, 1 if pins had different value -1 if error

INT8 mcp23017_WriteMask	(	MCP23017 *	obj,
		UINT16	val,
		UINT16	mask
	)

Set/clear all pins by providing a 16 bit value and mask. For example, to set pin 0 and 7, and clear pins 4 and 5, use command: mcp23017_WriteMask(0x40, 0b0000000010000001, 0b0000000010110001);

Parameters

obj	Structure with data for MCP23017 chip
val	16-bit pin values
mask	16-bit mask

Returns: Returns 0 if OK, else returns a non-zero value if error

INT8 mcp23017_WritePin	(	MCP23017 *	obj,
		UINT8	pinVal
	)

Write value to pin. For example, to set pin GPA5, use command: mcp23017_WritePin(0x40, MCP23017_GPA5 | MCP23017_SETPIN) Or, to clear pin GPB7, use command: mcp23017_WritePin(0x40, MCP23017_GPB7 | MCP23017_CLEARPIN)

Parameters

obj	Structure with data for MCP23017 chip
pinVal	Indicates what pin to set/clear, and value. Bits 0-3 give pin's address, and bit 7 it's value

Returns: Returns 0 if OK, else returns a non-zero value if error

Data Structures

Macros

Typedefs

Functions

Detailed Description

Description

Configuration

Macro Definition Documentation

Typedef Documentation

Function Documentation