AdafruitResistiveTouchScreen Class Reference

Description

Concrete implementation of TouchScreenAdapter for Adafruit's resistive TouchScreen class.

Provides a number of class methods to 'tune-in' the mapping of the raw resistance values in X and Y mapped to the display's X and Y pixel position. This will need to be done for each screen/MCU combination.

The Z pressure can also be mapped but do not recommend this as the reported pressures are not very repeatable.

Resistive screens will never be as consistent as capacitive ones but Some screen and board combinations work better than other - I suspect this is due to better pullup resistors.

#include <AdafruitResistiveTouchScreen.h>

Inheritance diagram for AdafruitResistiveTouchScreen:

Public Member Functions
	AdafruitResistiveTouchScreen (uint8_t pinXPos, uint8_t pinYPos, uint8_t pinXNeg, uint8_t pinYNeg, uint16_t ohms=300, uint16_t displayWidth=240, uint16_t displayHeight=320)
	Construct a new Resistive Touch Screen object. More...
	~AdafruitResistiveTouchScreen ()
	Destroy the AdafruitResistiveTouchScreen object.
TouchScreenAdapter::TouchPoint	getTouchPoint (void)
	Get the TouchPoint struct. More...
TouchScreenAdapter::TouchPoint	getTouchPointRaw (void)
	Get the raw TouchPoint struct. More...
bool	begin (void)
	Empty begin() implementation. More...
void	setMinRawY (uint16_t limit)
	Set the minimun raw Y value. More...
void	setMinRawX (uint16_t limit)
	Set the minimun raw X value. More...
void	setMaxRawX (uint16_t limit)
	Set the maximum raw X value. More...
void	setMaxRawY (uint16_t limit)
	Set the maximum raw Y value. More...
void	setMinRawZ (uint16_t limit)
	Set the maximum raw Z value. More...
void	setMaxRawZ (uint16_t limit)
	Set the maximum raw Z value. More...
Public Member Functions inherited from TouchScreenAdapter
void	setDisplayWidth (uint16_t widthPx)
	Set the native (non-rotated) display width (X) in pixels. More...
void	setDisplayHeight (uint16_t heightPx)
	Set the native (non-rotated) display height (Y) in pixels. More...
virtual TouchScreenAdapter::TouchPoint	getTouchPoint (void)=0
	Get the TouchPoint object. More...
virtual TouchScreenAdapter::TouchPoint	getTouchPointRaw (void)=0
	Get a TouchPoint struct containing raw values from the underlying library. More...
virtual bool	begin (void)=0
	For compatibility with the Arduino library convention. More...
void	setRotation (uint8_t r)
	Set the rotation touch screen. More...

Additional Inherited Members
Protected Attributes inherited from TouchScreenAdapter
uint8_t	rotation = 0
	The current rotation of the touch panel. Default is 0 (native orientation).
uint16_t	DISPLAY_WIDTH = 240
	The non-rotated width of the display in pixels.
uint16_t	DISPLAY_HEIGHT = 320
	The non-rotated height of the display in pixels.
uint16_t	displayWidth = DISPLAY_WIDTH
	The (optionally rotated) width of the display in pixels.
uint16_t	displayHeight = DISPLAY_HEIGHT
	The (optionally rotated) height of the display in pixels.

Constructor & Destructor Documentation

AdafruitResistiveTouchScreen()

AdafruitResistiveTouchScreen::AdafruitResistiveTouchScreen ( uint8_t  pinXPos, uint8_t  pinYPos, uint8_t  pinXNeg, uint8_t  pinYNeg, uint16_t  ohms = 300, uint16_t  displayWidth = 240, uint16_t  displayHeight = 320  )

inline

Construct a new Resistive Touch Screen object.

Parameters

pinXPos	can be a digital pin
pinYPos	Must be an analog pin, use "An" notation!
pinXNeg	must be an analog pin, use "An" notation!
pinYNeg	can be a digital pin
ohms	Measurement of ohms between pinXPos and PinXNeg (default 300). Can improve touch accuracy.
displayWidth	Native width of display with no rotation set (default 240)
displayHeight	Native height of display with no rotation set (default 320)

Member Function Documentation

begin()

bool AdafruitResistiveTouchScreen::begin ( void  )

inlinevirtual

Empty begin() implementation.

Returns

true Always.

false Never.

Implements TouchScreenAdapter.

getTouchPoint()

TouchScreenAdapter::TouchPoint AdafruitResistiveTouchScreen::getTouchPoint ( void  )

inlinevirtual

Get the TouchPoint struct.

The TouchPoint is populated with X and Y mapped from the raw resistance values to display pixel position.

Returns

TouchScreenAdapter::TouchPoint

Implements TouchScreenAdapter.

getTouchPointRaw()

TouchScreenAdapter::TouchPoint AdafruitResistiveTouchScreen::getTouchPointRaw ( void  )

inlinevirtual

Get the raw TouchPoint struct.

The TouchPoint is populated with the raw resistance values from the Adafruit TouchScreen library.

Use these values to measure and set the raw min/max X and Y values.

Returns

TouchScreenAdapter::TouchPoint

Implements TouchScreenAdapter.

setMaxRawX()

void AdafruitResistiveTouchScreen::setMaxRawX ( uint16_t  limit )

inline

Set the maximum raw X value.

Parameters

limit

The maximum X value reported by getTouchPointRaw()

setMaxRawY()

void AdafruitResistiveTouchScreen::setMaxRawY ( uint16_t  limit )

inline

Set the maximum raw Y value.

Parameters

limit

The maximum Y value reported by getTouchPointRaw()

setMaxRawZ()

void AdafruitResistiveTouchScreen::setMaxRawZ ( uint16_t  limit )

inline

Set the maximum raw Z value.

Parameters

limit

The maximum Z value reported by getTouchPointRaw()

setMinRawX()

void AdafruitResistiveTouchScreen::setMinRawX ( uint16_t  limit )

inline

Set the minimun raw X value.

Parameters

limit

The minimum X value reported by getTouchPointRaw()

setMinRawY()

void AdafruitResistiveTouchScreen::setMinRawY ( uint16_t  limit )

inline

Set the minimun raw Y value.

Parameters

limit

The minimum Y value reported by getTouchPointRaw()

setMinRawZ()

void AdafruitResistiveTouchScreen::setMinRawZ ( uint16_t  limit )

inline

Set the maximum raw Z value.

Parameters

limit

The maximum Z value reported by getTouchPointRaw()

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

• src/AdafruitResistiveTouchScreen.h