Public Member Functions
void	begin (uint8_t addr)

void	begin (void)

void	pinMode (uint8_t p, uint8_t d)

void	digitalWrite (uint8_t p, uint8_t d)

void	pullUp (uint8_t p, uint8_t d)

uint8_t	digitalRead (uint8_t p)

void	writeGPIOAB (uint16_t)

uint16_t	readGPIOAB ()

uint8_t	readGPIO (uint8_t b)

void	setupInterrupts (uint8_t mirroring, uint8_t open, uint8_t polarity)

void	setupInterruptPin (uint8_t p, uint8_t mode)

uint8_t	getLastInterruptPin ()

uint8_t	getLastInterruptPinValue ()

Member Function Documentation

void Adafruit_MCP23017::begin ( uint8_t addr )

Initializes the MCP23017 given its HW selected address, see datasheet for Address selection.

void Adafruit_MCP23017::begin ( void )

Initializes the default MCP23017, with 000 for the configurable part of the address

void Adafruit_MCP23017::pinMode	(	uint8_t	p,
		uint8_t	d
	)

Sets the pin mode to either INPUT or OUTPUT

uint8_t Adafruit_MCP23017::readGPIO ( uint8_t b )

Read a single port, A or B, and return its current 8 bit value. Parameter b should be 0 for GPIOA, and 1 for GPIOB.

uint16_t Adafruit_MCP23017::readGPIOAB ( )

Reads all 16 pins (port A and B) into a single 16 bits variable.

void Adafruit_MCP23017::setupInterruptPin	(	uint8_t	pin,
		uint8_t	mode
	)

Set's up a pin for interrupt. uses arduino MODEs: CHANGE, FALLING, RISING.

Note that the interrupt condition finishes when you read the information about the port / value that caused the interrupt or you read the port itself. Check the datasheet can be confusing.

void Adafruit_MCP23017::setupInterrupts	(	uint8_t	mirroring,
		uint8_t	openDrain,
		uint8_t	polarity
	)

Configures the interrupt system. both port A and B are assigned the same configuration. Mirroring will OR both INTA and INTB pins. Opendrain will set the INT pin to value or open drain. polarity will set LOW or HIGH on interrupt. Default values after Power On Reset are: (false,flase, LOW) If you are connecting the INTA/B pin to arduino 2/3, you should configure the interupt handling as FALLING with the default configuration.

void Adafruit_MCP23017::writeGPIOAB ( uint16_t ba )

Writes all the pins in one go. This method is very useful if you are implementing a multiplexed matrix and want to get a decent refresh rate.

The documentation for this class was generated from the following files:

firmware/lib/Adafruit_MCP23017/Adafruit_MCP23017.h
firmware/lib/Adafruit_MCP23017/Adafruit_MCP23017.cpp

Public Member Functions

Member Function Documentation