SCD40Sensor Class Reference

A class to interface with the Sensirion SCD40 sensor for CO2 data collection. More...

#include <SCD40Sensor.h>

Inheritance diagram for SCD40Sensor:

Collaboration diagram for SCD40Sensor:

Public Member Functions
	SCD40Sensor (TwoWire *i2c_bus=&Wire)
	Default constructor for the SCD40Sensor class.
	SCD40Sensor (unsigned long minimum_period, TwoWire *i2c_bus=&Wire)
	Parameterized constructor for the SCD40Sensor class.
bool	verify () override
	Verifies the connection and readiness of the SCD40 sensor.
String	readData () override
	Reads sensor data and returns it in CSV format.
void	readDataPacket (uint8_t *&packet) override
	Reads sensor data and appends it to the packet byte array.
String	decodeToCSV (uint8_t *&packet) override
	Decodes the packet data and returns it in CSV format.
Public Member Functions inherited from Sensor
	Sensor (String sensor_name, String csv_header, unsigned long minimum_period)
	Sensor (String sensor_name, String csv_header)
	Sensor (String sensor_name, String csv_header, int fields)
	Construct a new Sensor object with default minimum_period of 0 (depreciated)
	Sensor (String sensor_name, String csv_header, int fields, unsigned long minimum_period)
	Construct a new Sensor object (Depreciated)
unsigned long	getPeriod () const
	Get the minimum minimum_period between sensor reads in ms.
void	setPeriod (int minimum_period)
	Set the minimum minimum_period between sensor reads in ms.
unsigned long	getLastExecution () const
	Get the system time of the last execution in ms.
void	setLastExecution (int last_execution)
	Set the system time of the last execution in ms.
const String &	getSensorCSVHeader () const
	Get the csv header string associated with this sensor.
void	getDataPacket (uint32_t &sensor_id, uint8_t *&packet)
	Append the data from a sensor to the packet if the minium period is satisfied.
String	readEmpty () const
	Returns CSV line in the same format as readData() but with "-" instead of data.
String	getDataCSV ()
	Uses readData and readEmpty to get the data-filled or empty-celled CSV line for the sensor.
Public Member Functions inherited from Device
	Device (String device_name)
	Default constructor, sets a max_attempt of 1 (device recovery won't be attempted)
	Device (String device_name, int max_attempts, int wait_factor)
const String &	getDeviceName ()
bool	getVerified ()
	Get if the Device is Verified.
void	recoveryConfig (int max_attempts, int wait_factor)
	Set recovery config (used keep default constructor)
void	setWaitFactor (int wait_factor)
	Set wait_factor.
void	setMaxAttempts (int max_attempts)
	Set max_attempts.
bool	attemptConnection ()
	If the sensor is verified, return true, if not and it has been long enough since the last attempt (decided by wait_factor and attempt_number), attempt to reverify (reinitialize) it.

Private Attributes
SensirionI2cScd4x	scd
TwoWire *	i2c_bus

Additional Inherited Members
Protected Attributes inherited from Sensor
int	num_fields
Protected Attributes inherited from Device
bool	verified
String	device_name

Detailed Description

A class to interface with the Sensirion SCD40 sensor for CO2 data collection.

The SCD40Sensor class is responsible for interacting with the SCD40 sensor to gather CO2 data. It provides the CO2 concentration in parts per million (ppm) and the temperature in degrees Celsius.

This class inherits from the Sensor base class and overrides its virtual methods to implement the specific functionality required to read and verify data from the SCD40 sensor.

Key functionalities:

• Verify sensor connection and setup.
• Retrieve sensor readings in CSV format for easy integration with data logging systems.
• Get sensor name and CSV header for consistency in data handling.

Constructor & Destructor Documentation

SCD40Sensor() [1/2]

SCD40Sensor::SCD40Sensor

(

TwoWire *

i2c_bus = &Wire

)

Default constructor for the SCD40Sensor class.

Initializes the sensor object with a default minimum period of 0 milliseconds.

SCD40Sensor() [2/2]

SCD40Sensor::SCD40Sensor	(	unsigned long	minimum_period,
		TwoWire *	i2c_bus = &Wire
	)

Parameterized constructor for the SCD40Sensor class.

This constructor initializes the SCD40Sensor with a specified minimum period between sensor readings. It passes sensor-specific information like the name, CSV header, number of fields, and the minimum period between reads to the base Sensor class constructor

Parameters

minimum_period

The minimum time (in milliseconds) between consecutive sensor reads.

Member Function Documentation

decodeToCSV()

String SCD40Sensor::decodeToCSV ( uint8_t *&  packet )

overridevirtual

Decodes the packet data and returns it in CSV format.

Decodes the packet data from the SCD40 sensor and returns it in CSV format. The data includes CO2 concentration in parts per million (ppm) and temperature in degrees Celsius.

Parameters

packet

- Packet to decode.

Returns

String - A string containing the sensor readings

Reimplemented from Sensor.

readData()

String SCD40Sensor::readData ( )

overridevirtual

Reads sensor data and returns it in CSV format.

Reads data from the SCD40 sensor and returns it in CSV format. The data includes CO2 concentration in parts per million (ppm) and temperature in degrees Celsius.

Returns

String - A string containing the sensor readings

Implements Sensor.

readDataPacket()

void SCD40Sensor::readDataPacket ( uint8_t *&  packet )

overridevirtual

Reads sensor data and appends it to the packet byte array.

Reads data from the SCD40 sensor and appends it to the passed uint8_t array pointer, incrementing it while doing so. The data includes CO2 concentration in parts per million (ppm) and temperature in degrees Celsius.

Parameters

packet

- Pointer to the packet byte array.

Reimplemented from Sensor.

verify()

bool SCD40Sensor::verify ( )

overridevirtual

Verifies the connection and readiness of the SCD40 sensor.

This function initializes the sensor and checks if the sensor is properly connected and ready for reading data.

Returns

true - If the sensor is detected and successfully initialized.

false - If the sensor is not detected or fails to initialize.

Implements Sensor.

Member Data Documentation

i2c_bus

TwoWire* SCD40Sensor::i2c_bus

private

scd

SensirionI2cScd4x SCD40Sensor::scd

private

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

• SCD40Sensor.h
• SCD40Sensor.cpp