#include <IoAbstractionWire.h>

Inheritance diagram for MPR121IoAbstraction:

Public Member Functions
	MPR121IoAbstraction (uint8_t addr, pinid_t intPin=IO_PIN_NOT_DEFINED, WireType wirePtr=nullptr)

void	begin (int maxTouchPin, MPR121ConfigType configType, uint8_t configReg1=0x10, uint8_t configReg2=0x20)

void	pinDirection (pinid_t pin, uint8_t mode) override

void	attachInterrupt (pinid_t pin, RawIntHandler intHandler, uint8_t mode) override

bool	runLoop () override

void	electrodeSettingsForPin (pinid_t pin, uint8_t touchThreshold, uint8_t releaseThreshold, uint8_t current=0, uint8_t chargeTime=0)

uint16_t	getOutOfRangeRegister ()

void	configureDebounce (uint8_t debounceTouch, uint8_t debounceRelease)

uint16_t	read2ndFilteredData (uint8_t pin)

void	setPinLedCurrent (pinid_t pin, uint8_t pwr)

void	softwareReset ()

void	initDevice () override

void	writeReg8 (uint8_t reg, uint8_t data)

void	writeReg16 (uint8_t reg, uint16_t data)

uint8_t	readReg8 (uint8_t reg)

uint16_t	readReg16 (uint8_t reg)

Public Member Functions inherited from Standard16BitDevice
void	writeValue (pinid_t pin, uint8_t value) override

uint8_t	readValue (pinid_t pin) override

void	writePort (pinid_t pin, uint8_t port) override

uint8_t	readPort (pinid_t pin) override

void	clearChangeFlags ()

void	setReadPort (int port)

bool	isReadPortSet (int port) const

bool	isWritePortSet (int port) const

bool	isInitNeeded () const

void	markInitialised ()

Public Member Functions inherited from BasicIoAbstraction
uint8_t	digitalRead (pinid_t p)

void	digitalWrite (pinid_t p, uint8_t v)

uint8_t	digitalReadS (pinid_t p)

void	digitalWriteS (pinid_t p, uint8_t v)

void	writePortS (pinid_t p, uint8_t v)

uint8_t	readPortS (pinid_t p)

void	pinMode (pinid_t pin, uint8_t mode)

bool	sync ()

Protected Member Functions
void	enableTouchSupportOnPin (pinid_t pin)

Additional Inherited Members
Protected Attributes inherited from Standard16BitDevice
uint16_t	lastRead

uint16_t	toWrite

uint8_t	flags

Detailed Description

The MPR121IoAbstraction class provide a wide range of the capabilities of the MPR121 chip using the regular abstraction method such that they can be used with switches, LCDs, encoders, keyboards etc, similar to how you use device pins. For the additional functionality that is not directly provided, you can access the chips registers and set these particular extended functions up directly.

To use in touch mode you need to setup the registers before calling pinMode to set directions up. There are some helper functions to do some of the legwork, but given the shear number of possible configurations many of the touch registers need to be set up manually.

Constructor & Destructor Documentation

◆ MPR121IoAbstraction()

MPR121IoAbstraction::MPR121IoAbstraction	(	uint8_t	addr,
		pinid_t	intPin = `IO_PIN_NOT_DEFINED`,
		WireType	wirePtr = `nullptr`
	)

explicit

create an instance of the abstraction that communicates with the device and extends Arduino like functions for the pins on the device. This constructor takes the I2C address, and optionally an interrupt pin and wire implementation. Any interrupt pin provided will be set up on your behalf automatically.

Parameters

addr	the address on the I2C bus of the device
intPin	optionally a pin on the board that the devices interrupt pin is connected to
wirePtr	optionally an alternative wire implementation, EG Wire1, or other non standard I2C device.

Member Function Documentation

◆ begin()

void MPR121IoAbstraction::begin	(	int	maxTouchPin,
		MPR121ConfigType	configType,
		uint8_t	configReg1 = `0x10`,
		uint8_t	configReg2 = `0x20`
	)

Call this to start the device, it will initialise the touch sensor up to maxTouchPin, and set basic configuration options, this should be largely compatible with the Adafruit library, and therefore should work with the shield without too many issues. Note that if you configure more than 4 touch pins you cannot use GPIO at the same time.

Parameters

maxTouchPin	the maximum touch pin zero based
configType	either MPR121_MANUAL_CONFIG, MPR121_AUTO_CONFIG
configReg1	optionally the first config register (default 0x10)
configReg2	optionally the second config register (default 0x20)

◆ pinDirection()

void MPR121IoAbstraction::pinDirection	(	pinid_t	pin,
		uint8_t	mode
	)

overridevirtual

Sets the pin direction similar to pinMode, pin direction on this device supports INPUT, OUTPUT and LED_CURRENT_OUTPUT which enables the onboard LED controller, and then you use the setPinLedCurrent to control instead of digital write.

Parameters

pin	the pin to set direction for on this device
mode	for this device, INPUT, OUTPUT or AW9523_LED_OUTPUT

Reimplemented from BasicIoAbstraction.

◆ attachInterrupt()

void MPR121IoAbstraction::attachInterrupt	(	pinid_t	pin,
		RawIntHandler	intHandler,
		uint8_t	mode
	)

overridevirtual

Attaches an interrupt to the device and links it to the arduino pin. On this device nearly all interrupt modes are supported, including CHANGE, RISING, FALLING and are selective.

Reimplemented from BasicIoAbstraction.

◆ runLoop()

bool MPR121IoAbstraction::runLoop ( )

overridevirtual

updates settings on the board after changes

Reimplemented from BasicIoAbstraction.

◆ electrodeSettingsForPin()

void MPR121IoAbstraction::electrodeSettingsForPin	(	pinid_t	pin,
		uint8_t	touchThreshold,
		uint8_t	releaseThreshold,
		uint8_t	current = `0`,
		uint8_t	chargeTime = `0`
	)

Set the electrode settings for a pin, should only ever be called once the pin is set as input, it will turn the pin into a touch pin. These take values in line with the datasheet, which should be consulted for the correct value ranges. This should be called before setting pin direction to input. It is assumed the device is in stop mode by calling softwareReset and before the begin call.

Parameters

pin	the pin to configure for
current	the current to be used
chargeTime	the charge time to be used
touchThreshold	the touch threshold as per value determined from testing
releaseThreshold	the release threshold has per value determined from test.

◆ getOutOfRangeRegister()

uint16_t MPR121IoAbstraction::getOutOfRangeRegister ( )

Returns: the current status of the Out Of Range register on the device. See the datasheet for more details.

◆ configureDebounce()

void MPR121IoAbstraction::configureDebounce	(	uint8_t	debounceTouch,
		uint8_t	debounceRelease
	)

Debounce configuration takes value for both touch and release and is in conformance with the datasheet. Each is a value between 0 and 7. It is assumed the device is in stop mode by calling softwareReset and before the begin call.

Parameters

debounceTouch
debounceRelease

◆ read2ndFilteredData()

uint16_t MPR121IoAbstraction::read2ndFilteredData ( uint8_t pin )

Read the electrode filtered data, which is after the 2nd filter from the datasheet. This reads Electrode Data Registers 0x04-0x1D. See datasheet for more detail.

Parameters

pin	the pin number

Returns: the value from the registers

◆ setPinLedCurrent()

void MPR121IoAbstraction::setPinLedCurrent	(	pinid_t	pin,
		uint8_t	pwr
	)

Enable or disable the LED controller mode of the pin, the power parameter is a value between 0 and 255 that represents the dimming level for that pin.

Parameters

pin	the pin to control
pwr	the current to provide, based on the global control setting, default 0..37mA.

◆ softwareReset()

void MPR121IoAbstraction::softwareReset ( )

Perform a software reset of the device. Make sure you've called sync at least once before calling.

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

src/IoAbstractionWire.h
src/IoAbstractionWire.cpp

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ MPR121IoAbstraction()

Member Function Documentation

◆ begin()

◆ pinDirection()

◆ attachInterrupt()

◆ runLoop()

◆ electrodeSettingsForPin()

◆ getOutOfRangeRegister()

◆ configureDebounce()

◆ read2ndFilteredData()

◆ setPinLedCurrent()

◆ softwareReset()