Provides PWM-based display backlight control with the help of an attached MCU. More...

#include <displaycontroller.h>

Inheritance diagram for DisplayController:

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Collaboration diagram for DisplayController:

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Signals
void	enabledChanged () const
	Serial communication with the PWM generator MCU has turned on or off.

void	serialPortNameChanged () const
	The serial port device filename used for communication with the PWM generator MCU has changed.

void	baudRateChanged () const
	The baud rate used for serial communication with the PWM generator MCU has changed.

void	onChanged () const
	The display has turned on or off.

void	brightnessChanged () const
	The display brightness level while on has changed.

void	idleTimeoutChanged () const
	The wait time in seconds after which the display is turned off has changed.

void	fadeDurationChanged () const
	The duration in milliseconds for an animated fade between the two ends of the brightness range has changed.

void	fadeEasingChanged () const
	The easing curve used when fading between display brightness levels has changed.

Public Member Functions
	DisplayController (QObject *parent=nullptr)
	Create a display backlight controller.

bool	enabled () const
	Whether serial communication with the PWM generator MCU is enabled.

void	setEnabled (bool enabled)
	Turn serial communication with the PWM generator MCU on or off.

QString	serialPortName () const
	The serial port device filename used for communication with the PWM generator MCU.

void	setSerialPortName (const QString &serialPortName)
	Set the serial port device filename used for communication with the PWM generator MCU.

qint32	baudRate () const
	The baud rate used for serial communication with the PWM generator MCU.

void	setBaudRate (qint32 rate)
	Set the baud rate used for serial communication with the PWM generator MCU.

bool	on () const
	Whether the display is on or off.

void	setOn (bool on)
	Turn the display on or off.

qreal	brightness () const
	The display brightness level while on.

void	setBrightness (qreal brightness)
	Set the display brightness level while on.

int	idleTimeout () const
	The wait time in seconds after which the display is turned off.

void	setIdleTimeout (int timeout)
	Set the wait time in seconds after which the display is turned off.

Q_INVOKABLE void	resetIdleTimeout ()
	Reset the auto-turnoff timer.

int	fadeDuration () const
	The duration in milliseconds for an animated fade between the two ends of the brightness range.

void	setFadeDuration (int fadeDuration)
	Set the duration in milliseconds for an animated fade between the two ends of the brightness range.

QEasingCurve	fadeEasing () const
	The easing curve used when fading between display brightness levels.

void	setFadeEasing (const QEasingCurve &fadeEasing)
	Set the easing curve used when fading between display brightness levels.

void	classBegin () override
	Implements the `QQmlParserStatus` interface.

void	componentComplete () override
	Implements the `QQmlParserStatus` interface.

Properties
bool	enabled
	Toggle serial communication with the PWM generator MCU.

QString	serialPortName
	Serial port device filename used for communication with the PWM generator MCU.

qint32	baudRate
	Baud rate used for serial communication with the PWM generator MCU.

bool	on
	Toggle the display on or off.

qreal	brightness
	Display brightness level while on.

int	idleTimeout
	Wait time in seconds after which the display is turned off.

int	fadeDuration
	Duration in milliseconds for an animated fade between the two ends of the brightness range.

QEasingCurve	fadeEasing
	Easing curve used when fading between display brightness levels.

Detailed Description

Provides PWM-based display backlight control with the help of an attached MCU.

Performs serial port communication to a MCU (microcontroller unit) programmed to drive a HDMI display's backlight brightness by way of a PWM signal. The intended effect is to smoothly fade in and out the display for interactions with the project's onboard GUI (see fadeDuration).

An additional feature is support for automatically turning the display off after a determined idle period (see idleTimeout)

The attached MCU is assumed to accept writes of integer values between 0 and 255, representing intended display backlight brightness, on serial.

In the Hyelicht project, the attached MCU is an Arduino Nano 3.0 (AVR ATmega328). The Arduino sketch used to program it is provided in the source file support/arduino_pwm_generator.cpp.

Implements QQmlParserStatus for use from QML.

See also: QSerialPort; QSerialPortInfo; QQmlParserStatus

Constructor & Destructor Documentation

◆ DisplayController()

DisplayController::DisplayController ( QObject * parent = nullptr )

explicit

Create a display backlight controller.

Parameters

parent Parent object

Member Function Documentation

◆ baudRate()

qint32 DisplayController::baudRate ( ) const

The baud rate used for serial communication with the PWM generator MCU.

Returns: Serial baud rate.

See also: baudRate (property); setBaudRate; baudRateChanged; serialPortName

◆ baudRateChanged

void DisplayController::baudRateChanged ( ) const

signal

The baud rate used for serial communication with the PWM generator MCU has changed.

See also: baudRate; setBaudRate

◆ brightness()

qreal DisplayController::brightness ( ) const

The display brightness level while on.

This property is independent of the value of the property on.

Returns: Display brightness level between 0.0 and 1.0.

See also: brightness (property); setBrightness; brightnessChanged; on

◆ brightnessChanged

void DisplayController::brightnessChanged ( ) const

signal

The display brightness level while on has changed.

See also: brightness; setBrightness

◆ enabled()

bool DisplayController::enabled ( ) const

Whether serial communication with the PWM generator MCU is enabled.

Returns: Serial communication on or off.

See also: enabled (property); setEnabled; enabledChanged

◆ enabledChanged

void DisplayController::enabledChanged ( ) const

signal

Serial communication with the PWM generator MCU has turned on or off.

See also: enabled; setEnabled

◆ fadeDuration()

int DisplayController::fadeDuration ( ) const

The duration in milliseconds for an animated fade between the two ends of the brightness range.

Returns: Duration in milliseconds.

See also: fadeDuration (property); setFadeDuration; fadeDurationChanged; fadeEasing

◆ fadeDurationChanged

void DisplayController::fadeDurationChanged ( ) const

signal

The duration in milliseconds for an animated fade between the two ends of the brightness range has changed.

See also: fadeDuration; setFadeDuration

◆ fadeEasing()

QEasingCurve DisplayController::fadeEasing ( ) const

The easing curve used when fading between display brightness levels.

Returns: Easing curve.

See also: fadeEasing (property); setFadeEasing; fadeEasingChanged; fadeDuration

◆ fadeEasingChanged

void DisplayController::fadeEasingChanged ( ) const

signal

The easing curve used when fading between display brightness levels has changed.

See also: fadeEasing; setFadeEasing

◆ idleTimeout()

int DisplayController::idleTimeout ( ) const

The wait time in seconds after which the display is turned off.

Returns: Wait time in seconds.

See also: idleTimeout (property); setIdleTimeout; idleTimeoutChanged; resetIdleTimeout

◆ idleTimeoutChanged

void DisplayController::idleTimeoutChanged ( ) const

signal

The wait time in seconds after which the display is turned off has changed.

See also: idleTimeout; setIdleTimeout

◆ on()

bool DisplayController::on ( ) const

Whether the display is on or off.

When on, the display brightness is set to the current value of brightness.

When off, the display brightness is set to 0 (without changing brightness).

Returns: Display on or off.

See also: on (property); setOn; onChanged; brightness

◆ onChanged

void DisplayController::onChanged ( ) const

signal

The display has turned on or off.

See also: on; setOn

◆ resetIdleTimeout()

void DisplayController::resetIdleTimeout ( )

Reset the auto-turnoff timer.

Begins a new wait with the duration set as idleTimeout.

See also: idleTimeout; setIdleTimeout; idleTimeoutChanged; resetIdleTimeout

◆ serialPortName()

QString DisplayController::serialPortName ( ) const

The serial port device filename used for communication with the PWM generator MCU.

Returns: Serial port device filename.

See also: serialPortName (property); setSerialPortName; serialPortNameChanged; baudRate

◆ serialPortNameChanged

void DisplayController::serialPortNameChanged ( ) const

signal

The serial port device filename used for communication with the PWM generator MCU has changed.

See also: serialPortName; setSerialPortName

◆ setBaudRate()

void DisplayController::setBaudRate ( qint32 rate )

Set the baud rate used for serial communication with the PWM generator MCU.

Parameters

rate	Serial baud rate.

See also: baudRate; baudRateChanged; serialPortName

◆ setBrightness()

void DisplayController::setBrightness ( qreal brightness )

Set the display brightness level while on.

Parameters

brightness Display brightness level between 0.0 and 1.0.

See also: brightness; brightnessChanged; on

◆ setEnabled()

void DisplayController::setEnabled ( bool enabled )

Turn serial communication with the PWM generator MCU on or off.

Parameters

enabled Serial communication on or off.

See also: enabled; enabledChanged

◆ setFadeDuration()

void DisplayController::setFadeDuration ( int fadeDuration )

Set the duration in milliseconds for an animated fade between the two ends of the brightness range.

The actual duration of a brightness fade is scaled by the delta between the old and the new brightness levels, as a fraction of the full range of 0.0 - 1.0.

Can be set to 0 to disable fading and change to new brightness levels immediately instead.

Parameters

fadeDuration Duration in milliseconds.

See also: fadeDuration; fadeDurationChanged; fadeEasing

◆ setFadeEasing()

void DisplayController::setFadeEasing ( const QEasingCurve & fadeEasing )

Set the easing curve used when fading between display brightness levels.

Parameters

fadeEasing Easing curve.

See also: fadeEasing; fadeEasingChanged; fadeDuration

◆ setIdleTimeout()

void DisplayController::setIdleTimeout ( int timeout )

Set the wait time in seconds after which the display is turned off.

Can be set to 0 to turn off the auto-turnoff behavior.

Parameters

timeout Wait time in seconds.

See also: idleTimeout; idleTimeoutChanged; resetIdleTimeout

◆ setOn()

void DisplayController::setOn ( bool on )

Turn the display on or off.

When turned on, the display brightness is set to the current value of brightness.

When turned off, the display brightness is set to 0 (without changing brightness).

Parameters

on	Display on or off.

See also: on; onChanged; brightness

◆ setSerialPortName()

void DisplayController::setSerialPortName ( const QString & serialPortName )

Set the serial port device filename used for communication with the PWM generator MCU.

Parameters

serialPortName Serial port device filename.

See also: serialPortName; serialPortNameChanged; baudRate

Property Documentation

◆ baudRate

qint32 DisplayController::baudRate

readwrite

Baud rate used for serial communication with the PWM generator MCU.

Defaults to 115200.

See also: setBaudRate; baudRateChanged; serialPortName

◆ brightness

qreal DisplayController::brightness

readwrite

Display brightness level while on.

Display brightness is set in a range between 0.0 and 1.0.

This property is independent of the value of the property on.

Defaults to 1.0.

See also: setBrightness; brightnessChanged; on

◆ enabled

bool DisplayController::enabled

readwrite

Toggle serial communication with the PWM generator MCU.

Defaults to false.

See also: setEnabled; enabledChanged; serialPortName; baudRate

◆ fadeDuration

int DisplayController::fadeDuration

readwrite

Duration in milliseconds for an animated fade between the two ends of the brightness range.

The actual duration of a brightness fade is scaled by the delta between the old and the new brightness levels, as a fraction of the full range of 0.0 - 1.0.

Can be set to 0 to disable fading and change to new brightness levels immediately instead.

Defaults to 400.

See also: setFadeDuration; fadeDurationChanged; fadeEasing

◆ fadeEasing

QEasingCurve DisplayController::fadeEasing

readwrite

Easing curve used when fading between display brightness levels.

Defaults to QEasingCurve::InCubic.

See also: setFadeEasing; fadeEasingChanged; fadeDuration

◆ idleTimeout

int DisplayController::idleTimeout

readwrite

Wait time in seconds after which the display is turned off.

Can be set to 0 to turn off the auto-turnoff behavior.

Defaults to 20.

See also: setIdleTimeout; idleTimeoutChanged; resetIdleTimeout

◆ on

bool DisplayController::on

readwrite

Toggle the display on or off.

When turned on, the display brightness is set to the current value of brightness.

When turned off, the display brightness is set to 0 (without changing brightness).

Defaults to true.

See also: setOn; onChanged; brightness

◆ serialPortName

QString DisplayController::serialPortName

readwrite

Serial port device filename used for communication with the PWM generator MCU.

Defaults to /dev/ttyUSB0.

See also: setSerialPortName; serialPortNameChanged; baudRate

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

/__w/hyelicht/hyelicht/src/displaycontroller.h
/__w/hyelicht/hyelicht/src/displaycontroller.cpp

Signals

Public Member Functions

Properties

Detailed Description

Constructor & Destructor Documentation

◆ DisplayController()

Member Function Documentation

◆ baudRate()

◆ baudRateChanged

◆ brightness()

◆ brightnessChanged

◆ enabled()

◆ enabledChanged

◆ fadeDuration()

◆ fadeDurationChanged

◆ fadeEasing()

◆ fadeEasingChanged

◆ idleTimeout()

◆ idleTimeoutChanged

◆ on()

◆ onChanged

◆ resetIdleTimeout()

◆ serialPortName()

◆ serialPortNameChanged

◆ setBaudRate()

◆ setBrightness()

◆ setEnabled()

◆ setFadeDuration()

◆ setFadeEasing()

◆ setIdleTimeout()

◆ setOn()

◆ setSerialPortName()

Property Documentation

◆ baudRate

◆ brightness

◆ enabled

◆ fadeDuration

◆ fadeEasing

◆ idleTimeout

◆ on

◆ serialPortName