sTodo-m5paper-client/libraries/M5Unit-ENV/src/unit/unit_SHT40.hpp
2025-06-30 20:47:33 +02:00

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7.4 KiB
C++

/*
* SPDX-FileCopyrightText: 2024 M5Stack Technology CO LTD
*
* SPDX-License-Identifier: MIT
*/
/*!
@file unit_SHT40.hpp
@brief SHT40 Unit for M5UnitUnified
*/
#ifndef M5_UNIT_ENV_UNIT_SHT40_HPP
#define M5_UNIT_ENV_UNIT_SHT40_HPP
#include <M5UnitComponent.hpp>
#include <m5_utility/container/circular_buffer.hpp>
#include <limits> // NaN
namespace m5 {
namespace unit {
/*!
@namespace sht40
@brief For SHT40
*/
namespace sht40 {
/*!
@enum Precision
@brief precision level
*/
enum class Precision : uint8_t {
High, //!< High precision (high repeatability)
Medium, //!< Medium precision (medium repeatability)
Low //!< Lowest precision (low repeatability)
};
/*!
@enum Heater
@brief Heater behavior
*/
enum class Heater : uint8_t {
Long, //!< Activate heater for 1s
Short, //!< Activate heater for 0.1s
None //!< Not activate heater
};
/*!
@struct Data
@brief Measurement data group
*/
struct Data {
std::array<uint8_t, 6> raw{}; //!< RAW data
bool heater{}; //!< Measured data after heater is activated if true
//! temperature (Celsius)
inline float temperature() const
{
return celsius();
}
float celsius() const; //!< temperature (Celsius)
float fahrenheit() const; //!< temperature (Fahrenheit)
float humidity() const; //!< humidity (RH)
};
} // namespace sht40
/*!
@class UnitSHT40
@brief Temperature and humidity, sensor unit
*/
class UnitSHT40 : public Component, public PeriodicMeasurementAdapter<UnitSHT40, sht40::Data> {
M5_UNIT_COMPONENT_HPP_BUILDER(UnitSHT40, 0x44);
public:
/*!
@struct config_t
@brief Settings for begin
*/
struct config_t {
//! Start periodic measurement on begin?
bool start_periodic{true};
//! Precision level if start on begin
sht40::Precision precision{sht40::Precision::High};
//! Heater behavior if start on begin
sht40::Heater heater{sht40::Heater::None};
//! Heater duty cycle if start on begin [~ 0.05f]
float heater_duty{0.05f};
};
explicit UnitSHT40(const uint8_t addr = DEFAULT_ADDRESS)
: Component(addr), _data{new m5::container::CircularBuffer<sht40::Data>(1)}
{
auto ccfg = component_config();
ccfg.clock = 400 * 1000U;
component_config(ccfg);
}
virtual ~UnitSHT40()
{
}
virtual bool begin() override;
virtual void update(const bool force = false) override;
///@name Settings for begin
///@{
/*! @brief Gets the configration */
inline config_t config()
{
return _cfg;
}
//! @brief Set the configration
inline void config(const config_t& cfg)
{
_cfg = cfg;
}
///@}
///@name Measurement data by periodic
///@{
//! @brief Oldest measured temperature (Celsius)
inline float temperature() const
{
return !empty() ? oldest().temperature() : std::numeric_limits<float>::quiet_NaN();
}
//! @brief Oldest measured temperature (Celsius)
inline float celsius() const
{
return !empty() ? oldest().celsius() : std::numeric_limits<float>::quiet_NaN();
}
//! @brief Oldest measured temperature (Fahrenheit)
inline float fahrenheit() const
{
return !empty() ? oldest().fahrenheit() : std::numeric_limits<float>::quiet_NaN();
}
//! @brief Oldest measured humidity (RH)
inline float humidity() const
{
return !empty() ? oldest().humidity() : std::numeric_limits<float>::quiet_NaN();
}
///@}
///@name Periodic measurement
///@{
/*!
@brief Start periodic measurement
@param precision Sensor precision
@param heater Heater behavior
@param duty Duty for activate heater
@return True if successful
@note If the heater is Long or SHort, the heater will be active periodically within the specified duty
@warning Datasheet says "keepingin mind that the heater is designed for a maximal duty cycle of less than 5%"
*/
inline bool startPeriodicMeasurement(const sht40::Precision precision, const sht40::Heater heater,
const float duty = 0.05f)
{
return PeriodicMeasurementAdapter<UnitSHT40, sht40::Data>::startPeriodicMeasurement(precision, heater, duty);
}
/*!
@brief Stop periodic measurement
@return True if successful
*/
inline bool stopPeriodicMeasurement()
{
return PeriodicMeasurementAdapter<UnitSHT40, sht40::Data>::stopPeriodicMeasurement();
}
///@}
///@name Single shot measurement
///@{
/*!
@brief Measurement single shot
@param[out] data Measuerd data
@param precision Sensor precision
@param heater Heater behavior
@return True if successful
@note Blocking until the process is complete
@warning During periodic detection runs, an error is returned
@warning If heater is activated, the accuracy of the returned value is not guaranteed
@sa UnitSHT40::startPeriodicMeasurement
*/
bool measureSingleshot(sht40::Data& d, const sht40::Precision precision = sht40::Precision::High,
const sht40::Heater heater = sht40::Heater::None);
///@}
///@name Reset
///@{
/*!
@brief Soft reset
@return True if successful
*/
bool softReset();
/*!
@brief General reset
@details Reset using I2C general call
@return True if successful
@warning This is a reset by General command, the command is also sent to all devices with I2C connections
*/
bool generalReset();
///@}
///@name Serial number
///@{
/*!
@brief Read the serial number value
@param[out] serialNumber serial number value
@return True if successful
@note The serial number is 32 bit
@warning During periodic detection runs, an error is returned
*/
bool readSerialNumber(uint32_t& serialNumber);
/*!
@brief Read the serial number string
@param[out] serialNumber Output buffer
@return True if successful
@warning serialNumber must be at least 9 bytes
@warning During periodic detection runs, an error is returned
*/
bool readSerialNumber(char* serialNumber);
///@}
protected:
bool start_periodic_measurement(const sht40::Precision precision, const sht40::Heater heater, const float duty);
bool stop_periodic_measurement();
bool read_measurement(sht40::Data& d);
void reset_status();
bool soft_reset();
M5_UNIT_COMPONENT_PERIODIC_MEASUREMENT_ADAPTER_HPP_BUILDER(UnitSHT40, sht40::Data);
protected:
std::unique_ptr<m5::container::CircularBuffer<sht40::Data>> _data{};
config_t _cfg{};
uint8_t _cmd{}, _measureCmd{};
types::elapsed_time_t _latest_heater{}, _interval_heater{};
uint32_t _duration_measure{}, _duration_heater{};
};
///@cond
namespace sht40 {
namespace command {
constexpr uint8_t MEASURE_HIGH_HEATER_1S{0x39};
constexpr uint8_t MEASURE_HIGH_HEATER_100MS{0x32};
constexpr uint8_t MEASURE_HIGH{0xFD};
constexpr uint8_t MEASURE_MEDIUM_HEATER_1S{0x2F};
constexpr uint8_t MEASURE_MEDIUM_HEATER_100MS{0x24};
constexpr uint8_t MEASURE_MEDIUM{0xF6};
constexpr uint8_t MEASURE_LOW_HEATER_1S{0x1E};
constexpr uint8_t MEASURE_LOW_HEATER_100MS{0x15};
constexpr uint8_t MEASURE_LOW{0xE0};
constexpr uint8_t GET_SERIAL_NUMBER{0x89};
constexpr uint8_t SOFT_RESET{0x94};
} // namespace command
} // namespace sht40
///@endcond
} // namespace unit
} // namespace m5
#endif