Abstract base class for GPIO (General Purpose Input/Output) functions. More...

#include <HardwareGPIO.h>

Inheritance diagram for arduino::HardwareGPIO:

Public Member Functions
virtual int	analogRead (pin_size_t pinNumber)=0
	Read the value from the specified analog pin.

virtual void	analogReference (uint8_t mode)=0
	Configure the reference voltage used for analog input.

virtual void	analogWrite (pin_size_t pinNumber, int value)=0
	Write an analog value (PWM wave) to a pin.

virtual void	analogWriteFrequency (pin_size_t pin, uint32_t freq)=0
	Set the PWM frequency for analogWrite() on the specified pin.

virtual void	analogWriteResolution (uint8_t bits)=0
	Set the resolution of the analogWrite() values.

virtual PinStatus	digitalRead (pin_size_t pinNumber)=0
	Read the value from a specified digital pin.

virtual void	digitalWrite (pin_size_t pinNumber, PinStatus status)=0
	Write a HIGH or LOW value to a digital pin.

virtual void	noTone (uint8_t _pin)=0
	Stop the generation of a square wave triggered by tone()

virtual void	pinMode (pin_size_t pinNumber, PinMode pinMode)=0
	Configure the specified pin to behave as an input or output.

virtual unsigned long	pulseIn (uint8_t pin, uint8_t state, unsigned long timeout=1000000L)=0
	Read a pulse (HIGH or LOW) on a pin.

virtual unsigned long	pulseInLong (uint8_t pin, uint8_t state, unsigned long timeout=1000000L)=0
	Alternative to pulseIn() which is better at handling long pulses.

virtual void	tone (uint8_t _pin, unsigned int frequency, unsigned long duration=0)=0
	Generate a square wave of the specified frequency on a pin.

Detailed Description

Abstract base class for GPIO (General Purpose Input/Output) functions.

HardwareGPIO defines the interface for hardware abstraction of GPIO operations across different platforms and microcontrollers. This class provides a unified API for digital and analog I/O operations that can be implemented by platform-specific classes.

The class supports:

Digital pin operations (pinMode, digitalWrite, digitalRead)
Analog operations (analogRead, analogWrite, analogReference)
PWM and tone generation (analogWrite, tone, noTone)
Pulse measurement (pulseIn, pulseInLong)

Platform-specific implementations should inherit from this class and provide concrete implementations for all pure virtual methods. Examples include HardwareGPIO_RPI for Raspberry Pi, or similar classes for other platforms.

Note: All methods in this class are pure virtual and must be implemented by derived classes to provide platform-specific functionality.

See also: HardwareGPIO_RPI; PinMode; PinStatus

Member Function Documentation

◆ analogRead()

virtual int arduino::HardwareGPIO::analogRead ( pin_size_t pinNumber )

pure virtual

Read the value from the specified analog pin.

Parameters

pinNumber The analog pin to read from (A0, A1, etc.)

Returns: The analog reading on the pin (0-1023 for 10-bit ADC)

Implemented in arduino::GPIOWrapper, arduino::RemoteGPIO, arduino::HardwareGPIO_FIRMATA, arduino::HardwareGPIO_FTDI, and arduino::HardwareGPIO_RPI.

◆ analogReference()

virtual void arduino::HardwareGPIO::analogReference ( uint8_t mode )

pure virtual

Configure the reference voltage used for analog input.

Parameters

mode	The reference type (DEFAULT, INTERNAL, EXTERNAL, etc.)

Implemented in arduino::GPIOWrapper, arduino::RemoteGPIO, arduino::HardwareGPIO_FIRMATA, arduino::HardwareGPIO_FTDI, and arduino::HardwareGPIO_RPI.

◆ analogWrite()

virtual void arduino::HardwareGPIO::analogWrite	(	pin_size_t	pinNumber,
		int	value
	)

pure virtual

Write an analog value (PWM wave) to a pin.

Parameters

pinNumber	The pin to write to
value	The duty cycle (0-255 for 8-bit PWM)

Implemented in arduino::GPIOWrapper, arduino::RemoteGPIO, arduino::HardwareGPIO_FIRMATA, arduino::HardwareGPIO_FTDI, and arduino::HardwareGPIO_RPI.

◆ analogWriteFrequency()

virtual void arduino::HardwareGPIO::analogWriteFrequency	(	pin_size_t	pin,
		uint32_t	freq
	)

pure virtual

Set the PWM frequency for analogWrite() on the specified pin.

Parameters

pin	The pin number to configure PWM frequency for
freq	The desired PWM frequency in Hz

Note: Not all platforms support per-pin frequency control

Implemented in arduino::GPIOWrapper, arduino::RemoteGPIO, arduino::HardwareGPIO_RPI, arduino::HardwareGPIO_FIRMATA, and arduino::HardwareGPIO_FTDI.

◆ analogWriteResolution()

virtual void arduino::HardwareGPIO::analogWriteResolution ( uint8_t bits )

pure virtual

Set the resolution of the analogWrite() values.

Parameters

bits	The resolution in bits (e.g., 8 for 0-255, 10 for 0-1023)

Note: Default is typically 8 bits (0-255). Higher resolutions may not be supported on all platforms

Implemented in arduino::GPIOWrapper, arduino::RemoteGPIO, arduino::HardwareGPIO_RPI, arduino::HardwareGPIO_FIRMATA, and arduino::HardwareGPIO_FTDI.

◆ digitalRead()

virtual PinStatus arduino::HardwareGPIO::digitalRead ( pin_size_t pinNumber )

pure virtual

Read the value from a specified digital pin.

Parameters

pinNumber The pin number to read from

Returns: HIGH or LOW

Implemented in arduino::GPIOWrapper, arduino::RemoteGPIO, arduino::HardwareGPIO_FIRMATA, arduino::HardwareGPIO_FTDI, and arduino::HardwareGPIO_RPI.

◆ digitalWrite()

virtual void arduino::HardwareGPIO::digitalWrite	(	pin_size_t	pinNumber,
		PinStatus	status
	)

pure virtual

Write a HIGH or LOW value to a digital pin.

Parameters

pinNumber	The pin number to write to
status	The value to write (HIGH or LOW)

Implemented in arduino::GPIOWrapper, arduino::RemoteGPIO, arduino::HardwareGPIO_FIRMATA, arduino::HardwareGPIO_FTDI, and arduino::HardwareGPIO_RPI.

◆ noTone()

virtual void arduino::HardwareGPIO::noTone ( uint8_t _pin )

pure virtual

Stop the generation of a square wave triggered by tone()

Parameters

_pin	The pin on which to stop generating the tone

Implemented in arduino::GPIOWrapper, arduino::HardwareGPIO_FIRMATA, arduino::HardwareGPIO_FTDI, arduino::HardwareGPIO_RPI, and arduino::RemoteGPIO.

◆ pinMode()

virtual void arduino::HardwareGPIO::pinMode	(	pin_size_t	pinNumber,
		PinMode	pinMode
	)

pure virtual

Configure the specified pin to behave as an input or output.

Parameters

pinNumber	The pin number to configure
pinMode	The mode to set (INPUT, OUTPUT, INPUT_PULLUP, etc.)

Implemented in arduino::GPIOWrapper, arduino::RemoteGPIO, arduino::HardwareGPIO_FIRMATA, arduino::HardwareGPIO_FTDI, and arduino::HardwareGPIO_RPI.

◆ pulseIn()

virtual unsigned long arduino::HardwareGPIO::pulseIn	(	uint8_t	pin,
		uint8_t	state,
		unsigned long	timeout = `1000000L`
	)

pure virtual

Read a pulse (HIGH or LOW) on a pin.

Parameters

pin	The pin on which you want to read the pulse
state	Type of pulse to read (HIGH or LOW)
timeout	Timeout in microseconds (default 1 second)

Returns: The length of the pulse in microseconds, or 0 if timeout

Implemented in arduino::GPIOWrapper, arduino::HardwareGPIO_FIRMATA, arduino::HardwareGPIO_FTDI, arduino::HardwareGPIO_RPI, and arduino::RemoteGPIO.

◆ pulseInLong()

virtual unsigned long arduino::HardwareGPIO::pulseInLong	(	uint8_t	pin,
		uint8_t	state,
		unsigned long	timeout = `1000000L`
	)

pure virtual

Alternative to pulseIn() which is better at handling long pulses.

Parameters

pin	The pin on which you want to read the pulse
state	Type of pulse to read (HIGH or LOW)
timeout	Timeout in microseconds (default 1 second)

Returns: The length of the pulse in microseconds, or 0 if timeout

Implemented in arduino::GPIOWrapper, arduino::HardwareGPIO_FIRMATA, arduino::HardwareGPIO_FTDI, arduino::HardwareGPIO_RPI, and arduino::RemoteGPIO.

◆ tone()

virtual void arduino::HardwareGPIO::tone	(	uint8_t	_pin,
		unsigned int	frequency,
		unsigned long	duration = `0`
	)

pure virtual

Generate a square wave of the specified frequency on a pin.

Parameters

_pin	The pin on which to generate the tone
frequency	The frequency of the tone in hertz
duration	The duration of the tone in milliseconds (0 = continuous)

Implemented in arduino::GPIOWrapper, arduino::HardwareGPIO_FIRMATA, arduino::HardwareGPIO_FTDI, arduino::HardwareGPIO_RPI, and arduino::RemoteGPIO.

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

ArduinoCore-Linux/cores/arduino/HardwareGPIO.h

Public Member Functions

Detailed Description

Member Function Documentation

◆ analogRead()

◆ analogReference()

◆ analogWrite()

◆ analogWriteFrequency()

◆ analogWriteResolution()

◆ digitalRead()

◆ digitalWrite()

◆ noTone()

◆ pinMode()

◆ pulseIn()

◆ pulseInLong()

◆ tone()