Interface to the MCP23S17 16-Bit I/O Expander with Serial Interface (SPI) More...

#include <MCP23S17.h>

Public Member Functions
	MCP23S17 (int hardwareaddress, SPI &spi, PinName nCs, PinName nReset)
	Create an instance of the MCP23S17 connected via specfied SPI instance, with the specified address.
	MCP23S17 (int hardwareaddress, SPI &spi, PinName nCs)
	Create an instance of the MCP23S17 connected via specfied SPI instance, with the specified address, and Global reset only.
char	read (char reg_address)
	Read an Register address.
void	write (char reg_address, char data)
	Write to Register address.
void	bit (char reg_address, int bitnumber, bool high_low)
	Write to Bit in a register.
void	reset ()
	Resetting the MCP23S17.
char	iodira ()
	Read IODIRA.
void	iodira (char data)
	Write to IODIRA.
char	iodirb ()
	Read IODIRB.
void	iodirb (char data)
	Write to IODIRB.
char	ipola ()
	Read IPOLA.
void	ipola (char data)
	Write to IPOLA.
char	ipolb ()
	Read IPOLB.
void	ipolb (char data)
	Write to IPOLB.
char	gpintena ()
	Read GPINTENA.
void	gpintena (char data)
	Write to GPINTENA.
char	gpintenb ()
	Read GPINTENB.
void	gpintenb (char data)
	Write to GPINTENB.
char	defvala ()
	Read DEFVALA.
void	defvala (char data)
	Write to DEFVALA.
char	defvalb ()
	Read DEFVALB.
void	defvalb (char data)
	Write to DEFVALB.
char	intcona ()
	Read INTCONA.
void	intcona (char data)
	Write to INTCONA.
char	intconb ()
	Read INTCONB.
void	intconb (char data)
	Write to INTCONB.
char	iocon ()
	Read IOCON.
void	iocon (char data)
	Write to IOCON.
char	gppua ()
	Read GPPUA.
void	gppua (char data)
	Write to GPPUA.
char	gppub ()
	Read GPPUB.
void	gppub (char data)
	Write to GPPUB.
char	intfa ()
	Read INTFA.
char	intfb ()
	Read INTFB.
char	intcapa ()
	Read INTCAPA.
char	intcapb ()
	Read INTCAPB.
char	gpioa ()
	Read GPIOA.
void	gpioa (char data)
	Write to GPIOA.
char	gpiob ()
	Read GPIOB.
void	gpiob (char data)
	Write to GPIOB.
char	olata ()
	Read OLATA.
void	olata (char data)
	Write to OLATA.
char	olatb ()
	Read OLATB.
void	olatb (char data)
	Write to OLATB.
void	intmirror (bool mirror)
	Write to IOCON.MIRROR.
void	intpol (bool polarity)
	Write to IOCON.INTPOL.

Detailed Description

Interface to the MCP23S17 16-Bit I/O Expander with Serial Interface (SPI)

Using the driver:

remenber to setup SPI in main routine.
remenber to setup interrupt pin or pins in main routine (if you are using interrupts).

Defaults in this driver:

as default is hardware adressing "On" and if disable use "0" in hardwareaddress when creating the instance.
as default is interrupt pins "Active High".
as default is INTA is associated with PortA and INTB is associated with PortB.

Limitations of using this driver:

can't use Open-Drain output.
can't use Sequential Operation mode bit.
can't use BANK 1 addressing.

Definition at line 83 of file MCP23S17.h.

Constructor & Destructor Documentation

MCP23S17	(	int	hardwareaddress,
		SPI &	spi,
		PinName	nCs,
		PinName	nReset
	)

Create an instance of the MCP23S17 connected via specfied SPI instance, with the specified address.

Parameters:

hardwareaddress	The SPI hardware address 0-7 for this MCP23S17.
spi	The mbed SPI instance (make in main routine)
nCs	The SPI chip select pin.
nReset	The Hardware reset pin.

Definition at line 30 of file MCP23S17.cpp.

MCP23S17	(	int	hardwareaddress,
		SPI &	spi,
		PinName	nCs
	)

Create an instance of the MCP23S17 connected via specfied SPI instance, with the specified address, and Global reset only.

Parameters:

hardwareaddress	The SPI hardware address 0-7 for this MCP23S17.
spi	The mbed SPI instance (make in main routine)
nCs	The SPI chip select pin.

Definition at line 36 of file MCP23S17.cpp.

Member Function Documentation

void bit	(	char	reg_address,
		int	bitnumber,
		bool	high_low
	)

Write to Bit in a register.

Parameters:

reg_adress	The selected register to write to.
bit	The bit with to write in, values from 1 to 8
high_low	The value to write the bit True = '1' and False = '0'.

Definition at line 52 of file MCP23S17.cpp.

char defvala ( )

Read DEFVALA.

DEFAULT COMPARE REGISTER FOR INTERRUPT-ON-CHANGE The default comparison value is configured in the DEFVAL register, If enabled (via GPINTEN and INTCON).

Returns:: The 8 bits read.

Definition at line 141 of file MCP23S17.cpp.

void defvala ( char data )

Write to DEFVALA.

DEFAULT COMPARE REGISTER FOR INTERRUPT-ON-CHANGE The default comparison value is configured in the DEFVAL register, If enabled (via GPINTEN and INTCON).

Parameters:

data	The 8 bits to write to DEVALA register.

Definition at line 146 of file MCP23S17.cpp.

char defvalb ( )

Read DEFVALB.

DEFAULT COMPARE REGISTER FOR INTERRUPT-ON-CHANGE The default comparison value is configured in the DEFVAL register, If enabled (via GPINTEN and INTCON).

Returns:: The 8 bits read.

Definition at line 151 of file MCP23S17.cpp.

void defvalb ( char data )

Write to DEFVALB.

DEFAULT COMPARE REGISTER FOR INTERRUPT-ON-CHANGE The default comparison value is configured in the DEFVAL register, If enabled (via GPINTEN and INTCON).

Parameters:

data	The 8 bits to write to DEVALB register.

Definition at line 156 of file MCP23S17.cpp.

char gpintena ( )

Read GPINTENA.

INTERRUPT-ON-CHANGE CONTROL REGISTER The GPINTEN register controls the interrupt-onchange feature for each pin.

Returns:: The 8 bits read.

Definition at line 121 of file MCP23S17.cpp.

void gpintena ( char data )

Write to GPINTENA.

INTERRUPT-ON-CHANGE CONTROL REGISTER The GPINTEN register controls the interrupt-onchange feature for each pin.

Parameters:

data	The 8 bits to write to GPINTENA register.

Definition at line 126 of file MCP23S17.cpp.

void gpintenb ( char data )

Write to GPINTENB.

INTERRUPT-ON-CHANGE CONTROL REGISTER The GPINTEN register controls the interrupt-onchange feature for each pin.

Parameters:

data	The 8 bits to write to GPINTENB register.

Definition at line 136 of file MCP23S17.cpp.

char gpintenb ( )

Read GPINTENB.

INTERRUPT-ON-CHANGE CONTROL REGISTER The GPINTEN register controls the interrupt-onchange feature for each pin.

Returns:: The 8 bits read.

Definition at line 131 of file MCP23S17.cpp.

char gpioa ( )

Read GPIOA.

PORT REGISTER The GPIO register reflects the value on the port. Reading from this register reads the port. Writing to this register modifies the Output Latch (OLAT) register.

Returns:: The 8 bits read.

Definition at line 231 of file MCP23S17.cpp.

void gpioa ( char data )

Write to GPIOA.

PORT REGISTER The GPIO register reflects the value on the port. Reading from this register reads the port. Writing to this register modifies the Output Latch (OLAT) register.

Parameters:

data	The 8 bits to write to GPIOA register.

Definition at line 236 of file MCP23S17.cpp.

char gpiob ( )

Read GPIOB.

PORT REGISTER The GPIO register reflects the value on the port. Reading from this register reads the port. Writing to this register modifies the Output Latch (OLAT) register.

Returns:: The 8 bits read.

Definition at line 241 of file MCP23S17.cpp.

void gpiob ( char data )

Write to GPIOB.

PORT REGISTER The GPIO register reflects the value on the port. Reading from this register reads the port. Writing to this register modifies the Output Latch (OLAT) register.

Parameters:

data	The 8 bits to write to GPIOB register.

Definition at line 246 of file MCP23S17.cpp.

char gppua ( )

Read GPPUA.

PULL-UP RESISTOR CONFIGURATION REGISTER The GPPU register controls the pull-up resistors for the port pins.

Returns:: The 8 bits read.

Definition at line 191 of file MCP23S17.cpp.

void gppua ( char data )

Write to GPPUA.

PULL-UP RESISTOR CONFIGURATION REGISTER The GPPU register controls the pull-up resistors for the port pins.

Parameters:

data	The 8 bits to write to GPPUA register.

Definition at line 196 of file MCP23S17.cpp.

char gppub ( )

Read GPPUB.

PULL-UP RESISTOR CONFIGURATION REGISTER The GPPU register controls the pull-up resistors for the port pins.

Returns:: The 8 bits read.

Definition at line 201 of file MCP23S17.cpp.

void gppub ( char data )

Write to GPPUB.

PULL-UP RESISTOR CONFIGURATION REGISTER The GPPU register controls the pull-up resistors for the port pins.

Parameters:

data	The 8 bits to write to GPPUB register.

Definition at line 206 of file MCP23S17.cpp.

char intcapa ( )

Read INTCAPA.

INTERRUPT CAPTURE REGISTER - READ ONLY The INTCAP register captures the GPIO port value at the time the interrupt occurred. The register is ‘read only’ and is updated only when an interrupt occurs.

Returns:: The 8 bits read.

Definition at line 221 of file MCP23S17.cpp.

char intcapb ( )

Read INTCAPB.

INTERRUPT CAPTURE REGISTER - READ ONLY The INTCAP register captures the GPIO port value at the time the interrupt occurred. The register is ‘read only’ and is updated only when an interrupt occurs.

Returns:: The 8 bits read.

Definition at line 226 of file MCP23S17.cpp.

char intcona ( )

Read INTCONA.

INTERRUPT CONTROL REGISTER The INTCON register controls how the associated pin value is compared for the interrupt-on-change feature.

Returns:: The 8 bits read.

Definition at line 161 of file MCP23S17.cpp.

void intcona ( char data )

Write to INTCONA.

INTERRUPT CONTROL REGISTER The INTCON register controls how the associated pin value is compared for the interrupt-on-change feature.

Parameters:

data	The 8 bits to write to INTCONA register.

Definition at line 166 of file MCP23S17.cpp.

char intconb ( )

Read INTCONB.

INTERRUPT CONTROL REGISTER The INTCON register controls how the associated pin value is compared for the interrupt-on-change feature.

Returns:: The 8 bits read.

Definition at line 171 of file MCP23S17.cpp.

void intconb ( char data )

Write to INTCONB.

INTERRUPT CONTROL REGISTER The INTCON register controls how the associated pin value is compared for the interrupt-on-change feature.

Parameters:

data	The 8 bits to write to INTCONB register.

Definition at line 176 of file MCP23S17.cpp.

char intfa ( )

Read INTFA.

INTERRUPT FLAG REGISTER - READ ONLY The INTF register reflects the interrupt condition on the port pins of any pin that is enabled for interrupts via the GPINTEN register.

Returns:: The 8 bits read.

Definition at line 211 of file MCP23S17.cpp.

char intfb ( )

Read INTFB.

INTERRUPT FLAG REGISTER - READ ONLY The INTF register reflects the interrupt condition on the port pins of any pin that is enabled for interrupts via the GPINTEN register.

Returns:: The 8 bits read.

Definition at line 216 of file MCP23S17.cpp.

void intmirror ( bool mirror )

Write to IOCON.MIRROR.

IOCON REGISTER - INTERRUPT MIRROR BIT 1 = The INT pins are internally connected 0 = The INT pins are not connected. INTA is associated with PortA and INTB is associated with PortB

Parameters:

mirror write true ('1') or false ('0').

Definition at line 271 of file MCP23S17.cpp.

void intpol ( bool polarity )

Write to IOCON.INTPOL.

IOCON REGISTER - INTERRUPT POLARITY BIT This bit sets the polarity of the INT output pin. 1 = Active-high. 0 = Active-low.

Parameters:

polarity write true ('1') or false ('0').

Definition at line 285 of file MCP23S17.cpp.

char iocon ( )

Read IOCON.

CONFIGURATION REGISTER The IOCON register contains several bits for configuring the device.

Returns:: The 8 bits read.

Definition at line 181 of file MCP23S17.cpp.

void iocon ( char data )

Write to IOCON.

CONFIGURATION REGISTER The IOCON register contains several bits for configuring the device.

Parameters:

data	The 8 bits to write to IOCON register.

Definition at line 186 of file MCP23S17.cpp.

char iodira ( )

Read IODIRA.

I/O DIRECTION REGISTER Controls the direction of the data I/O.

Returns:: The 8 bits read.

Definition at line 81 of file MCP23S17.cpp.

void iodira ( char data )

Write to IODIRA.

I/O DIRECTION REGISTER Controls the direction of the data I/O.

Parameters:

data	The 8 bits to write to IODIRA register.

Definition at line 86 of file MCP23S17.cpp.

void iodirb ( char data )

Write to IODIRB.

I/O DIRECTION REGISTER Controls the direction of the data I/O.

Parameters:

data	The 8 bits to write to IODIRB register.

Definition at line 96 of file MCP23S17.cpp.

char iodirb ( )

Read IODIRB.

I/O DIRECTION REGISTER Controls the direction of the data I/O.

Returns:: The 8 bits read.

Definition at line 91 of file MCP23S17.cpp.

char ipola ( )

Read IPOLA.

INPUT POLARITY REGISTER This register allows the user to configure the polarity on the corresponding GPIO port bits.

Returns:: The 8 bits read.

Definition at line 101 of file MCP23S17.cpp.

void ipola ( char data )

Write to IPOLA.

INPUT POLARITY REGISTER This register allows the user to configure the polarity on the corresponding GPIO port bits.

Parameters:

data	The 8 bits to write to IPOLA register.

Definition at line 106 of file MCP23S17.cpp.

char ipolb ( )

Read IPOLB.

INPUT POLARITY REGISTER This register allows the user to configure the polarity on the corresponding GPIO port bits.

Returns:: The 8 bits read.

Definition at line 111 of file MCP23S17.cpp.

void ipolb ( char data )

Write to IPOLB.

INPUT POLARITY REGISTER This register allows the user to configure the polarity on the corresponding GPIO port bits.

Parameters:

data	The 8 bits to write to IPOLB register.

Definition at line 116 of file MCP23S17.cpp.

char olata ( )

Read OLATA.

OUTPUT LATCH REGISTER The OLAT register provides access to the output latches. A read from this register results in a read of the OLAT and not the port itself. A write to this register modifies the output latches that modifies the pins configured as outputs.

Returns:: The 8 bits read.

Definition at line 251 of file MCP23S17.cpp.

void olata ( char data )

Write to OLATA.

OUTPUT LATCH REGISTER The OLAT register provides access to the output latches. A read from this register results in a read of the OLAT and not the port itself. A write to this register modifies the output latches that modifies the pins configured as outputs.

Parameters:

data	The 8 bits to write to OLATA register.

Definition at line 256 of file MCP23S17.cpp.

char olatb ( )

Read OLATB.

OUTPUT LATCH REGISTER The OLAT register provides access to the output latches. A read from this register results in a read of the OLAT and not the port itself. A write to this register modifies the output latches that modifies the pins configured as outputs.

Returns:: The 8 bits read.

Definition at line 261 of file MCP23S17.cpp.

void olatb ( char data )

Write to OLATB.

OUTPUT LATCH REGISTER The OLAT register provides access to the output latches. A read from this register results in a read of the OLAT and not the port itself. A write to this register modifies the output latches that modifies the pins configured as outputs.

Parameters:

data	The 8 bits to write to OLATB register.

Definition at line 266 of file MCP23S17.cpp.

char read ( char reg_address )

Read an Register address.

Parameters:

reg_address The selected register to read from.

Returns:: The 8 bits read, but if GPIO register only the value of the inputs (outputs is read as "0").

Definition at line 42 of file MCP23S17.cpp.

void reset ( )

Resetting the MCP23S17.

Reset has to be pull down for min. 1uS to insure correct reset. This function pull down the reset pin for 5uS.

Definition at line 73 of file MCP23S17.cpp.

void write	(	char	reg_address,
		char	data
	)

Write to Register address.

Parameters:

reg_adress	The selected register to write to.
data	The 8 bits to write to the register, but if GPIO only the output will change.

Definition at line 47 of file MCP23S17.cpp.

Type:	Library
Created:	20 Jan 2016
Imports:	171
Forks:	2
Commits:	4
Dependents:	4
Dependencies:	0
Followers:	9

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MCP23S17 Class Reference

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

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Important changes to repositories hosted on mbed.com

MCP23S17 Class Reference

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Repository toolbox

Repository details

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