The DHT11 temperature and humidity sensor. More...

#include <DHT11.h>

Inheritance diagram for RumPi::DHT11:

Collaboration diagram for RumPi::DHT11:

Public Member Functions
	DHT11 (const bool isUsingPi5OrAbove, const unsigned int dhtPinNumber, const unsigned int maxTimings=85U)
	Builds a DHT11 on the given pin. More...

virtual	~DHT11 ()
	Destroys the sensor, turning it off first. More...

virtual void	TurnOn () override
	Turns the sensor on. More...

virtual void	TurnOff () override
	Turns the sensor off. More...

virtual void	ProcessRawValues () override
	Reads the sensor (rate-limited to ~once every 2 seconds) and, on a good read, feeds the temperature and humidity into their rolling averages. More...

virtual std::string	ToString () const override
	Serializes the sensor's current and averaged temperature (Celsius and Fahrenheit) and humidity to a string. More...

unsigned int	GetDHTPinNumber () const
	Gets the GPIO pin the sensor is wired to. More...

unsigned int	GetMaxTimings () const
	Gets the maximum number of signal transitions sampled per read (older bit-banged path). More...

float	GetAverageHumidity () const
	Gets the rolling-average humidity. More...

float	GetCurrentHumidity () const
	Gets the most recent humidity reading (not averaged). More...

float	GetAverageTemperatureInCelsius () const
	Gets the rolling-average temperature in Celsius. More...

float	GetCurrentTemperatureInCelsius () const
	Gets the most recent temperature reading in Celsius (not averaged). More...

float	GetAverageTemperatureInFahrenheit () const
	Gets the rolling-average temperature converted to Fahrenheit. More...

float	GetCurrentTemperatureInFahrenheit () const
	Gets the most recent temperature reading converted to Fahrenheit (not averaged). More...

Public Member Functions inherited from RumPi::BaseComponent
	BaseComponent ()
	Builds a base component with an unknown type and an empty name. More...

virtual	~BaseComponent ()
	Virtual destructor so deleting a component through a BaseComponent* also cleans up the concrete subclass. More...

virtual void	TurnOn ()=0
	Turns the component on (e.g. More...

virtual void	TurnOff ()=0
	Turns the component off. More...

virtual std::string	ToString () const =0
	Serializes the component's current readings to a string (usually JSON). More...

virtual void	ProcessRawValues ()=0
	Reads and processes the component's latest raw values (called once per poll). More...

virtual EComponentType	GetComponentType () const
	Gets the component's type. More...

const std::string &	GetName () const
	Gets the component's unique per-instance name. More...

void	SetName (const std::string &name)
	Sets the component's unique per-instance name. More...

Private Attributes
bool	myIsUsingPi5OrAbove
	Whether to use the Pi 5+ kernel sysfs read path (true) or the older bit-banged GPIO read (false). More...

unsigned int	myDHTPinNumber
	The GPIO pin the sensor is wired to (older bit-banged path). More...

unsigned int	myMaxTimings
	Maximum signal transitions to sample per read (older bit-banged path). More...

float	myCurrentHumidity
	The most recent humidity reading (percent), or NaN if none yet. More...

float	myCurrentTemperatureInCelsius
	The most recent temperature reading (Celsius), or NaN if none yet. More...

RollingAverage	myAverageHumidity
	Rolling average of humidity readings. More...

RollingAverage	myAverageTemperatureInCelsius
	Rolling average of temperature readings (Celsius). More...

std::chrono::steady_clock::time_point	myLastReadTime
	When the last successful read happened (the sensor needs ~2s between reads). More...

Additional Inherited Members
Static Public Member Functions inherited from RumPi::BaseComponent
static std::string	ComponentTypeToString (const EComponentType theComponentTypeToConvert)
	Maps an EComponentType to its string name. More...

static EComponentType	StringToComponentType (const std::string &theComponentTypeName)
	Maps a type name back to its EComponentType (the inverse of ComponentTypeToString), so the client can turn the type carried on the wire back into a value it can look an icon up with. More...

Protected Attributes inherited from RumPi::BaseComponent
EComponentType	myComponentType
	The kind of component this is (set by each concrete subclass). More...

std::string	myName
	A unique per-instance name, assigned when the component is added to the manager. More...

Detailed Description

The DHT11 temperature and humidity sensor.

Its readings tend to fluctuate, so they are averaged over time (via RollingAverage) for a stable value. Supports both the newer Pi 5+ kernel IIO read path and the older bit-banged GPIO read.

Author: Eddie O'Hagan

Date: 8/13/2026

Constructor & Destructor Documentation

◆ DHT11()

RumPi::DHT11::DHT11	(	const bool	isUsingPi5OrAbove,
		const unsigned int	dhtPinNumber,
		const unsigned int	maxTimings = `85U`
	)

Builds a DHT11 on the given pin.

Chooses the read path from isUsingPi5OrAbove, and initializes the last-read time to a few seconds ago so the first read is allowed immediately.

Author: Eddie O'Hagan

Date: 8/13/2026

DHT11 sensor(true, 13);

RumPi::DHT11::DHT11

DHT11(const bool isUsingPi5OrAbove, const unsigned int dhtPinNumber, const unsigned int maxTimings=85U)

Builds a DHT11 on the given pin.

Definition: DHT11.cpp:24

Parameters

[in]	isUsingPi5OrAbove	true to use the Pi 5+ kernel read path; false for the older bit-banged read.
[in]	dhtPinNumber	The GPIO pin the sensor is wired to (older path).
[in]	maxTimings	Maximum signal transitions to sample per read (older path).

◆ ~DHT11()

RumPi::DHT11::~DHT11 ( )

virtual

Destroys the sensor, turning it off first.

Author: Eddie O'Hagan

Date: 8/13/2026

DHT11* sensor = new DHT11(true, 13);

delete sensor;

Member Function Documentation

◆ GetAverageHumidity()

float RumPi::DHT11::GetAverageHumidity ( ) const

Gets the rolling-average humidity.

Author: Eddie O'Hagan

Date: 8/13/2026

float humidity = sensor.GetAverageHumidity();

Returns: The averaged humidity in percent, or NaN if no reading has been taken yet.

◆ GetAverageTemperatureInCelsius()

float RumPi::DHT11::GetAverageTemperatureInCelsius ( ) const

Gets the rolling-average temperature in Celsius.

Author: Eddie O'Hagan

Date: 8/13/2026

float tempC = sensor.GetAverageTemperatureInCelsius();

Returns: The averaged temperature in Celsius, or NaN if no reading has been taken yet.

◆ GetAverageTemperatureInFahrenheit()

float RumPi::DHT11::GetAverageTemperatureInFahrenheit ( ) const

Gets the rolling-average temperature converted to Fahrenheit.

Author: Eddie O'Hagan

Date: 8/13/2026

float tempF = sensor.GetAverageTemperatureInFahrenheit();

Returns: The averaged temperature in Fahrenheit, or NaN if no reading has been taken yet.

◆ GetCurrentHumidity()

float RumPi::DHT11::GetCurrentHumidity ( ) const

Gets the most recent humidity reading (not averaged).

Author: Eddie O'Hagan

Date: 8/13/2026

float humidity = sensor.GetCurrentHumidity();

Returns: The latest humidity reading in percent, or NaN if none yet.

◆ GetCurrentTemperatureInCelsius()

float RumPi::DHT11::GetCurrentTemperatureInCelsius ( ) const

Gets the most recent temperature reading in Celsius (not averaged).

Author: Eddie O'Hagan

Date: 8/13/2026

float tempC = sensor.GetCurrentTemperatureInCelsius();

Returns: The latest temperature in Celsius, or NaN if none yet.

◆ GetCurrentTemperatureInFahrenheit()

float RumPi::DHT11::GetCurrentTemperatureInFahrenheit ( ) const

Gets the most recent temperature reading converted to Fahrenheit (not averaged).

Author: Eddie O'Hagan

Date: 8/13/2026

float tempF = sensor.GetCurrentTemperatureInFahrenheit();

Returns: The latest temperature in Fahrenheit, or NaN if none yet.

◆ GetDHTPinNumber()

unsigned int RumPi::DHT11::GetDHTPinNumber ( ) const

Gets the GPIO pin the sensor is wired to.

Author: Eddie O'Hagan

Date: 8/13/2026

unsigned int pin = sensor.GetDHTPinNumber();

Returns: The sensor's GPIO pin number.

◆ GetMaxTimings()

unsigned int RumPi::DHT11::GetMaxTimings ( ) const

Gets the maximum number of signal transitions sampled per read (older bit-banged path).

Author: Eddie O'Hagan

Date: 8/13/2026

unsigned int maxTimings = sensor.GetMaxTimings();

Returns: The configured maximum timings.

◆ ProcessRawValues()

void RumPi::DHT11::ProcessRawValues ( )

overridevirtual

Reads the sensor (rate-limited to ~once every 2 seconds) and, on a good read, feeds the temperature and humidity into their rolling averages.

Uses the Pi 5+ kernel sysfs path or the older bit-banged GPIO read depending on how the sensor was constructed; a failed or flaky read keeps the previous values.

Author: Eddie O'Hagan

Date: 8/13/2026

sensor.ProcessRawValues(); //call each poll; internally rate-limited.

Implements RumPi::BaseComponent.

◆ ToString()

std::string RumPi::DHT11::ToString ( ) const

overridevirtual

Serializes the sensor's current and averaged temperature (Celsius and Fahrenheit) and humidity to a string.

Author: Eddie O'Hagan

Date: 8/13/2026

std::string data = sensor.ToString();

Returns: A multi-line string of the sensor's readings.

Implements RumPi::BaseComponent.

◆ TurnOff()

void RumPi::DHT11::TurnOff ( )

overridevirtual

Turns the sensor off.

The DHT11 needs no active teardown here, so this is a no-op.

Author: Eddie O'Hagan

Date: 8/13/2026

sensor.TurnOff();

Implements RumPi::BaseComponent.

◆ TurnOn()

void RumPi::DHT11::TurnOn ( )

overridevirtual

Turns the sensor on.

The DHT11 needs no active setup here, so this is a no-op.

Author: Eddie O'Hagan

Date: 8/13/2026

sensor.TurnOn();

Implements RumPi::BaseComponent.

Member Data Documentation

◆ myAverageHumidity

RollingAverage RumPi::DHT11::myAverageHumidity

private

Rolling average of humidity readings.

◆ myAverageTemperatureInCelsius

RollingAverage RumPi::DHT11::myAverageTemperatureInCelsius

private

Rolling average of temperature readings (Celsius).

◆ myCurrentHumidity

float RumPi::DHT11::myCurrentHumidity

private

The most recent humidity reading (percent), or NaN if none yet.

◆ myCurrentTemperatureInCelsius

float RumPi::DHT11::myCurrentTemperatureInCelsius

private

The most recent temperature reading (Celsius), or NaN if none yet.

◆ myDHTPinNumber

unsigned int RumPi::DHT11::myDHTPinNumber

private

The GPIO pin the sensor is wired to (older bit-banged path).

◆ myIsUsingPi5OrAbove

bool RumPi::DHT11::myIsUsingPi5OrAbove

private

Whether to use the Pi 5+ kernel sysfs read path (true) or the older bit-banged GPIO read (false).

◆ myLastReadTime

std::chrono::steady_clock::time_point RumPi::DHT11::myLastReadTime

private

When the last successful read happened (the sensor needs ~2s between reads).

◆ myMaxTimings

unsigned int RumPi::DHT11::myMaxTimings

private

Maximum signal transitions to sample per read (older bit-banged path).

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

Source/Headers/RumPi/Components/DHT11.h
Source/Implementations/RumPi/Components/DHT11.cpp

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ DHT11()

◆ ~DHT11()

Member Function Documentation

◆ GetAverageHumidity()

◆ GetAverageTemperatureInCelsius()

◆ GetAverageTemperatureInFahrenheit()

◆ GetCurrentHumidity()

◆ GetCurrentTemperatureInCelsius()

◆ GetCurrentTemperatureInFahrenheit()

◆ GetDHTPinNumber()

◆ GetMaxTimings()

◆ ProcessRawValues()

◆ ToString()

◆ TurnOff()

◆ TurnOn()

Member Data Documentation

◆ myAverageHumidity

◆ myAverageTemperatureInCelsius

◆ myCurrentHumidity

◆ myCurrentTemperatureInCelsius

◆ myDHTPinNumber

◆ myIsUsingPi5OrAbove

◆ myLastReadTime

◆ myMaxTimings