Namespaces
namespace	Constants

namespace	DefaultConfig
	Default NTC configuration constants.

Classes
struct	ntc_lookup_entry_t
	Lookup table entry structure. More...

struct	ntc_lookup_table_t
	Lookup table structure. More...

Functions
bool	ConvertResistanceToTemperatureBeta (float resistance_ohms, float resistance_at_25c, float beta_value, float *temperature_celsius) noexcept
	Convert resistance to temperature using beta parameter.

bool	ConvertTemperatureToResistanceBeta (float temperature_celsius, float resistance_at_25c, float beta_value, float *resistance_ohms) noexcept
	Convert temperature to resistance using beta parameter.

bool	ConvertResistanceToTemperatureSteinhartHart (float resistance_ohms, float coeff_a, float coeff_b, float coeff_c, float *temperature_celsius) noexcept
	Convert resistance to temperature using Steinhart-Hart equation.

bool	ConvertTemperatureToResistanceSteinhartHart (float temperature_celsius, float coeff_a, float coeff_b, float coeff_c, float *resistance_ohms) noexcept
	Convert temperature to resistance using Steinhart-Hart equation.

bool	ConvertResistanceToTemperatureDefault (float resistance_ohms, float *temperature_celsius) noexcept
	Convert resistance to temperature using default Steinhart-Hart coefficients.

bool	ConvertTemperatureToResistanceDefault (float temperature_celsius, float *resistance_ohms) noexcept
	Convert temperature to resistance using default Steinhart-Hart coefficients.

bool	CalculateThermistorResistance (float voltage_thermistor, float reference_voltage, float series_resistance, float *resistance_ohms) noexcept
	Calculate thermistor resistance from voltage divider.

bool	CalculateThermistorVoltage (float resistance_ohms, float reference_voltage, float series_resistance, float *voltage_thermistor) noexcept
	Calculate voltage across thermistor from resistance.

bool	CalculateVoltageDividerRatio (float resistance_ohms, float series_resistance, float *ratio) noexcept
	Calculate voltage divider ratio.

bool	ValidateResistance (float resistance_ohms, float min_resistance, float max_resistance) noexcept
	Validate resistance value.

bool	ValidateTemperature (float temperature_celsius, float min_temperature, float max_temperature) noexcept
	Validate temperature value.

bool	ValidateVoltage (float voltage_volts, float min_voltage, float max_voltage) noexcept
	Validate voltage value.

bool	ValidateBetaValue (float beta_value) noexcept
	Validate beta value.

bool	ValidateSteinhartHartCoefficients (float coeff_a, float coeff_b, float coeff_c) noexcept
	Validate Steinhart-Hart coefficients.

bool	CalculateBetaValue (float temp1_celsius, float resistance1_ohms, float temp2_celsius, float resistance2_ohms, float *beta_value) noexcept
	Calculate beta value from two temperature-resistance pairs.

bool	CalculateSteinhartHartCoefficients (float temp1_celsius, float resistance1_ohms, float temp2_celsius, float resistance2_ohms, float temp3_celsius, float resistance3_ohms, float coeff_a, float coeff_b, float *coeff_c) noexcept
	Calculate Steinhart-Hart coefficients from three temperature-resistance pairs.

bool	CalculateTemperatureAccuracy (float resistance_ohms, float resistance_at_25c, float beta_value, float resistance_tolerance, float beta_tolerance, float *accuracy_celsius) noexcept
	Worst-case temperature error from the R25 and B tolerances.

bool	CalculateTemperatureAccuracy (float resistance_ohms, float resistance_tolerance, float beta_tolerance, float *accuracy_celsius) noexcept
	Temperature error estimate for the default part (R25 = 10 kOhm, B = 3435 K)

bool	CalculateOptimalSeriesResistance (float thermistor_resistance_at_25c, float beta_value, float min_temperature, float max_temperature, float *optimal_resistance) noexcept
	Calculate optimal series resistance for voltage divider.

bool	CalculateOptimalSeriesResistance (float thermistor_resistance_at_25c, float min_temperature, float max_temperature, float *optimal_resistance) noexcept
	Optimal series resistance assuming B = 3435 K.

const ntc_lookup_table_t *	GetNtcLookupTable (int ntc_type) noexcept
	Get lookup table for NTC type.

bool	FindTemperatureFromLookupTable (const ntc_lookup_table_t table, float resistance_ohms, float temperature_celsius) noexcept
	Find temperature using lookup table.

bool	FindResistanceFromLookupTable (const ntc_lookup_table_t table, float temperature_celsius, float resistance_ohms) noexcept
	Find resistance using lookup table.

bool	InterpolateLookupEntries (const ntc_lookup_entry_t &entry1, const ntc_lookup_entry_t &entry2, float resistance_ohms, float *temperature_celsius) noexcept
	Interpolate between two lookup table entries.

bool	BinarySearchLookupTable (const ntc_lookup_table_t table, float resistance_ohms, size_t lower_index, size_t *upper_index) noexcept
	Binary search in lookup table.

bool	ValidateLookupTable (const ntc_lookup_table_t *table) noexcept
	Validate lookup table.

void	GetLookupTableStats (const ntc_lookup_table_t table, float min_resistance, float max_resistance, float min_temperature, float max_temperature, size_t entry_count) noexcept
	Get lookup table statistics.

const ntc_lookup_table_t *	GetNtcG163Jft103Ft1sLookupTable () noexcept
	Get NTCG163JFT103FT1S lookup table.

const ntc_lookup_table_t *	GetNtcG164Jf103Ft1sLookupTable () noexcept
	Get NTCG164JF103FT1S lookup table.

const ntc_lookup_table_t *	GetNtcG163Jf103Ft1sLookupTable () noexcept
	Get NTCG163JF103FT1S lookup table.

Function Documentation

◆ BinarySearchLookupTable()

bool NTC::BinarySearchLookupTable	(	const ntc_lookup_table_t *	table,
		float	resistance_ohms,
		size_t *	lower_index,
		size_t *	upper_index
	)

noexcept

Binary search in lookup table.

Parameters

table	Lookup table
resistance_ohms	Target resistance
lower_index	Pointer to store lower index
upper_index	Pointer to store upper index

Returns: true if found, false otherwise

◆ CalculateBetaValue()

bool NTC::CalculateBetaValue	(	float	temp1_celsius,
		float	resistance1_ohms,
		float	temp2_celsius,
		float	resistance2_ohms,
		float *	beta_value
	)

noexcept

Calculate beta value from two temperature-resistance pairs.

Parameters

temp1_celsius	First temperature (°C)
resistance1_ohms	First resistance (ohms)
temp2_celsius	Second temperature (°C)
resistance2_ohms	Second resistance (ohms)
beta_value	Pointer to store calculated beta value

Returns: true if successful, false otherwise

◆ CalculateOptimalSeriesResistance() [1/2]

bool NTC::CalculateOptimalSeriesResistance	(	float	thermistor_resistance_at_25c,
		float	beta_value,
		float	min_temperature,
		float	max_temperature,
		float *	optimal_resistance
	)

noexcept

Calculate optimal series resistance for voltage divider.

The geometric mean of R at the two ends of the range, from the Beta equation with the given R25 and B.

Parameters

thermistor_resistance_at_25c	Thermistor resistance at 25°C (ohms)
beta_value	B (K), e.g. ntc_config_t::beta_value
min_temperature	Minimum temperature (°C)
max_temperature	Maximum temperature (°C)
optimal_resistance	Pointer to store optimal series resistance (ohms)

Returns: true if successful, false otherwise

◆ CalculateOptimalSeriesResistance() [2/2]

bool NTC::CalculateOptimalSeriesResistance	(	float	thermistor_resistance_at_25c,
		float	min_temperature,
		float	max_temperature,
		float *	optimal_resistance
	)

noexcept

Optimal series resistance assuming B = 3435 K.

Calculate optimal series resistance for voltage divider.

Deprecated:: Pass B: use the overload that takes beta_value.

Parameters

thermistor_resistance_at_25c	Thermistor resistance at 25°C (ohms)
min_temperature	Minimum temperature (°C)
max_temperature	Maximum temperature (°C)
optimal_resistance	Pointer to store optimal series resistance (ohms)

Returns: true if successful, false otherwise

◆ CalculateSteinhartHartCoefficients()

bool NTC::CalculateSteinhartHartCoefficients	(	float	temp1_celsius,
		float	resistance1_ohms,
		float	temp2_celsius,
		float	resistance2_ohms,
		float	temp3_celsius,
		float	resistance3_ohms,
		float *	coeff_a,
		float *	coeff_b,
		float *	coeff_c
	)

noexcept

Calculate Steinhart-Hart coefficients from three temperature-resistance pairs.

Solves 1/T = A + B*ln(R) + C*ln(R)^3 through the three points (in double precision), so the returned equation passes through all three. Pick points across the range you need, e.g. -40, 25 and 125 C from the datasheet table.

Parameters

temp1_celsius	First temperature (°C)
resistance1_ohms	First resistance (ohms)
temp2_celsius	Second temperature (°C)
resistance2_ohms	Second resistance (ohms)
temp3_celsius	Third temperature (°C)
resistance3_ohms	Third resistance (ohms)
coeff_a	Pointer to store coefficient A
coeff_b	Pointer to store coefficient B
coeff_c	Pointer to store coefficient C

Returns: true if successful, false otherwise

◆ CalculateTemperatureAccuracy() [1/2]

bool NTC::CalculateTemperatureAccuracy	(	float	resistance_ohms,
		float	resistance_at_25c,
		float	beta_value,
		float	resistance_tolerance,
		float	beta_tolerance,
		float *	accuracy_celsius
	)

noexcept

Worst-case temperature error from the R25 and B tolerances.

Converts R to T with the Beta equation, then adds the two worst-case errors: R25 tolerance, T^2/B * tol_R, and B tolerance, |T * (1 - T/T25)| * tol_B. For the NTCG163JF103FT1S (R25 +/- 1 %, B25/85 +/- 1 %) this reproduces the spec sheet's Table 3 Min/Max band: 0.26 C at 25 C, 1.1 C at 85 C.

Parameters

resistance_ohms	Thermistor resistance (ohms)
resistance_at_25c	R25 (ohms), e.g. ntc_config_t::resistance_at_25c
beta_value	B (K), e.g. ntc_config_t::beta_value
resistance_tolerance	R25 tolerance (fraction, 0.01 for 1 %)
beta_tolerance	B tolerance (fraction)
accuracy_celsius	Pointer to store the error bound (°C)

Returns: true if successful, false otherwise

◆ CalculateTemperatureAccuracy() [2/2]

bool NTC::CalculateTemperatureAccuracy	(	float	resistance_ohms,
		float	resistance_tolerance,
		float	beta_tolerance,
		float *	accuracy_celsius
	)

noexcept

Temperature error estimate for the default part (R25 = 10 kOhm, B = 3435 K)

Calculate temperature accuracy estimate.

Deprecated:: Pass R25 and B: use the six-argument overload.

Parameters

resistance_ohms	Thermistor resistance (ohms)
resistance_tolerance	Resistance tolerance (fraction)
beta_tolerance	Beta tolerance (fraction)
accuracy_celsius	Pointer to store accuracy estimate (°C)

Returns: true if successful, false otherwise

◆ CalculateThermistorResistance()

bool NTC::CalculateThermistorResistance	(	float	voltage_thermistor,
		float	reference_voltage,
		float	series_resistance,
		float *	resistance_ohms
	)

noexcept

Calculate thermistor resistance from voltage divider.

Parameters

voltage_thermistor	Voltage across thermistor (V)
reference_voltage	Reference voltage (V)
series_resistance	Series resistance (ohms)
resistance_ohms	Pointer to store thermistor resistance (ohms)

Returns: true if successful, false otherwise

◆ CalculateThermistorVoltage()

bool NTC::CalculateThermistorVoltage	(	float	resistance_ohms,
		float	reference_voltage,
		float	series_resistance,
		float *	voltage_thermistor
	)

noexcept

Calculate voltage across thermistor from resistance.

Parameters

resistance_ohms	Thermistor resistance (ohms)
reference_voltage	Reference voltage (V)
series_resistance	Series resistance (ohms)
voltage_thermistor	Pointer to store voltage across thermistor (V)

Returns: true if successful, false otherwise

◆ CalculateVoltageDividerRatio()

bool NTC::CalculateVoltageDividerRatio	(	float	resistance_ohms,
		float	series_resistance,
		float *	ratio
	)

noexcept

Calculate voltage divider ratio.

Parameters

resistance_ohms	Thermistor resistance (ohms)
series_resistance	Series resistance (ohms)
ratio	Pointer to store voltage ratio

Returns: true if successful, false otherwise

◆ ConvertResistanceToTemperatureBeta()

bool NTC::ConvertResistanceToTemperatureBeta	(	float	resistance_ohms,
		float	resistance_at_25c,
		float	beta_value,
		float *	temperature_celsius
	)

noexcept

Convert resistance to temperature using beta parameter.

Uses the beta parameter equation to calculate temperature from resistance. This is a simplified model that assumes a linear relationship in the temperature-resistance curve around the reference temperature.

Note: The beta parameter method is faster but less accurate than Steinhart-Hart, especially at temperature extremes.

Parameters

resistance_ohms	Thermistor resistance (ohms)
resistance_at_25c	Resistance at 25°C (ohms)
beta_value	Beta value (K), typically 3000-4000K for NTC thermistors
temperature_celsius	Pointer to store temperature (°C)

Returns: true if successful, false otherwise

Warning: Input resistance must be positive and non-zero. Beta value should be within valid range (1000-5000K).

◆ ConvertResistanceToTemperatureDefault()

bool NTC::ConvertResistanceToTemperatureDefault	(	float	resistance_ohms,
		float *	temperature_celsius
	)

noexcept

Convert resistance to temperature using default Steinhart-Hart coefficients.

The defaults (STEINHART_HART_A_/B_/C_) are fitted to the TDK NTCG163JF103FT1S; use ConvertResistanceToTemperatureSteinhartHart() with your own coefficients for any other part.

Parameters

resistance_ohms	Thermistor resistance (ohms)
temperature_celsius	Pointer to store temperature (°C)

Returns: true if successful, false otherwise

◆ ConvertResistanceToTemperatureSteinhartHart()

bool NTC::ConvertResistanceToTemperatureSteinhartHart	(	float	resistance_ohms,
		float	coeff_a,
		float	coeff_b,
		float	coeff_c,
		float *	temperature_celsius
	)

noexcept

Convert resistance to temperature using Steinhart-Hart equation.

Uses the Steinhart-Hart equation for high-accuracy temperature calculation. This method provides better accuracy across a wider temperature range compared to the beta parameter method.

The Steinhart-Hart equation: 1/T = A + B*ln(R) + C*ln(R)³

Note: This method is more computationally expensive but provides superior accuracy, especially at temperature extremes.

Parameters

resistance_ohms	Thermistor resistance (ohms)
coeff_a	Steinhart-Hart coefficient A (about 0.9e-3 for a 10 kOhm part)
coeff_b	Steinhart-Hart coefficient B (about 2.5e-4)
coeff_c	Steinhart-Hart coefficient C (about 1e-7 to 2e-7)
temperature_celsius	Pointer to store temperature (°C)

Returns: true if successful, false otherwise

See also: ValidateSteinhartHartCoefficients() to validate coefficients

◆ ConvertTemperatureToResistanceBeta()

bool NTC::ConvertTemperatureToResistanceBeta	(	float	temperature_celsius,
		float	resistance_at_25c,
		float	beta_value,
		float *	resistance_ohms
	)

noexcept

Convert temperature to resistance using beta parameter.

Parameters

temperature_celsius	Temperature (°C)
resistance_at_25c	Resistance at 25°C (ohms)
beta_value	Beta value (K)
resistance_ohms	Pointer to store resistance (ohms)

Returns: true if successful, false otherwise

◆ ConvertTemperatureToResistanceDefault()

bool NTC::ConvertTemperatureToResistanceDefault	(	float	temperature_celsius,
		float *	resistance_ohms
	)

noexcept

Convert temperature to resistance using default Steinhart-Hart coefficients.

Parameters

temperature_celsius	Temperature (°C)
resistance_ohms	Pointer to store resistance (ohms)

Returns: true if successful, false otherwise

◆ ConvertTemperatureToResistanceSteinhartHart()

bool NTC::ConvertTemperatureToResistanceSteinhartHart	(	float	temperature_celsius,
		float	coeff_a,
		float	coeff_b,
		float	coeff_c,
		float *	resistance_ohms
	)

noexcept

Convert temperature to resistance using Steinhart-Hart equation.

Solves C*x^3 + B*x + (A - 1/T) = 0 for x = ln(R) exactly (the C term included), so it is the inverse of ConvertResistanceToTemperatureSteinhartHart().

Parameters

temperature_celsius	Temperature (°C)
coeff_a	Steinhart-Hart coefficient A
coeff_b	Steinhart-Hart coefficient B
coeff_c	Steinhart-Hart coefficient C
resistance_ohms	Pointer to store resistance (ohms)

Returns: true if successful, false otherwise

◆ FindResistanceFromLookupTable()

bool NTC::FindResistanceFromLookupTable	(	const ntc_lookup_table_t *	table,
		float	temperature_celsius,
		float *	resistance_ohms
	)

noexcept

Find resistance using lookup table.

Parameters

table	Lookup table
temperature_celsius	Temperature value
resistance_ohms	Pointer to store resistance

Returns: true if found, false otherwise

◆ FindTemperatureFromLookupTable()

bool NTC::FindTemperatureFromLookupTable	(	const ntc_lookup_table_t *	table,
		float	resistance_ohms,
		float *	temperature_celsius
	)

noexcept

Find temperature using lookup table.

Parameters

table	Lookup table
resistance_ohms	Resistance value
temperature_celsius	Pointer to store temperature

Returns: true if found, false otherwise

◆ GetLookupTableStats()

void NTC::GetLookupTableStats	(	const ntc_lookup_table_t *	table,
		float *	min_resistance,
		float *	max_resistance,
		float *	min_temperature,
		float *	max_temperature,
		size_t *	entry_count
	)

noexcept

Get lookup table statistics.

Parameters

table	Lookup table
min_resistance	Pointer to store minimum resistance
max_resistance	Pointer to store maximum resistance
min_temperature	Pointer to store minimum temperature
max_temperature	Pointer to store maximum temperature
entry_count	Pointer to store entry count

◆ GetNtcG163Jf103Ft1sLookupTable()

const ntc_lookup_table_t * NTC::GetNtcG163Jf103Ft1sLookupTable ( )

noexcept

Get NTCG163JF103FT1S lookup table.

Returns: Pointer to lookup table

◆ GetNtcG163Jft103Ft1sLookupTable()

const ntc_lookup_table_t * NTC::GetNtcG163Jft103Ft1sLookupTable ( )

noexcept

Get NTCG163JFT103FT1S lookup table.

Returns: Pointer to lookup table

◆ GetNtcG164Jf103Ft1sLookupTable()

const ntc_lookup_table_t * NTC::GetNtcG164Jf103Ft1sLookupTable ( )

noexcept

Get NTCG164JF103FT1S lookup table.

Returns: Pointer to lookup table

◆ GetNtcLookupTable()

const ntc_lookup_table_t * NTC::GetNtcLookupTable ( int ntc_type )

noexcept

Get lookup table for NTC type.

Retrieves the pre-calculated lookup table for a specific NTC thermistor type. Lookup tables are optimized for fast temperature conversion with minimal computational overhead.

Parameters

ntc_type NTC thermistor type (e.g., NtcType::NtcG163Jf103Ft1S)

Returns: Pointer to lookup table (nullptr if not available for this type)

Note: Not all NTC types have pre-calculated lookup tables. Use NtcConversionMethod::Mathematical for unsupported types.

◆ InterpolateLookupEntries()

bool NTC::InterpolateLookupEntries	(	const ntc_lookup_entry_t &	entry1,
		const ntc_lookup_entry_t &	entry2,
		float	resistance_ohms,
		float *	temperature_celsius
	)

noexcept

Interpolate between two lookup table entries.

Parameters

entry1	First entry
entry2	Second entry
resistance_ohms	Target resistance
temperature_celsius	Pointer to store interpolated temperature

Returns: true if interpolation successful, false otherwise

◆ ValidateBetaValue()

bool NTC::ValidateBetaValue ( float beta_value )

noexcept

Validate beta value.

Parameters

beta_value Beta value to validate

Returns: true if valid, false otherwise

◆ ValidateLookupTable()

bool NTC::ValidateLookupTable ( const ntc_lookup_table_t * table )

noexcept

Validate lookup table.

Parameters

table Lookup table to validate

Returns: true if valid, false otherwise

◆ ValidateResistance()

bool NTC::ValidateResistance	(	float	resistance_ohms,
		float	min_resistance,
		float	max_resistance
	)

noexcept

Validate resistance value.

Parameters

resistance_ohms	Resistance value to validate
min_resistance	Minimum valid resistance
max_resistance	Maximum valid resistance

Returns: true if valid, false otherwise

◆ ValidateSteinhartHartCoefficients()

bool NTC::ValidateSteinhartHartCoefficients	(	float	coeff_a,
		float	coeff_b,
		float	coeff_c
	)

noexcept

Validate Steinhart-Hart coefficients.

Accepts finite coefficients with |A| <= 1e-2, 1e-4 <= B <= 1e-3 and |C| <= 1e-6, which covers NTC fits from about 1 kOhm to 1 MOhm (this part's C is 1.9e-7).

Parameters

coeff_a	Coefficient A
coeff_b	Coefficient B
coeff_c	Coefficient C

Returns: true if valid, false otherwise

◆ ValidateTemperature()

bool NTC::ValidateTemperature	(	float	temperature_celsius,
		float	min_temperature,
		float	max_temperature
	)

noexcept

Validate temperature value.

Parameters

temperature_celsius	Temperature value to validate
min_temperature	Minimum valid temperature
max_temperature	Maximum valid temperature

Returns: true if valid, false otherwise

◆ ValidateVoltage()

bool NTC::ValidateVoltage	(	float	voltage_volts,
		float	min_voltage,
		float	max_voltage
	)

noexcept

Validate voltage value.

Parameters

voltage_volts	Voltage value to validate
min_voltage	Minimum valid voltage
max_voltage	Maximum valid voltage

Returns: true if valid, false otherwise

Namespaces

Classes

Functions

Function Documentation

◆ BinarySearchLookupTable()

◆ CalculateBetaValue()

◆ CalculateOptimalSeriesResistance() [1/2]

◆ CalculateOptimalSeriesResistance() [2/2]

◆ CalculateSteinhartHartCoefficients()

◆ CalculateTemperatureAccuracy() [1/2]

◆ CalculateTemperatureAccuracy() [2/2]

◆ CalculateThermistorResistance()

◆ CalculateThermistorVoltage()

◆ CalculateVoltageDividerRatio()

◆ ConvertResistanceToTemperatureBeta()

◆ ConvertResistanceToTemperatureDefault()

◆ ConvertResistanceToTemperatureSteinhartHart()

◆ ConvertTemperatureToResistanceBeta()

◆ ConvertTemperatureToResistanceDefault()

◆ ConvertTemperatureToResistanceSteinhartHart()

◆ FindResistanceFromLookupTable()

◆ FindTemperatureFromLookupTable()

◆ GetLookupTableStats()

◆ GetNtcG163Jf103Ft1sLookupTable()

◆ GetNtcG163Jft103Ft1sLookupTable()

◆ GetNtcG164Jf103Ft1sLookupTable()

◆ GetNtcLookupTable()

◆ InterpolateLookupEntries()

◆ ValidateBetaValue()

◆ ValidateLookupTable()

◆ ValidateResistance()

◆ ValidateSteinhartHartCoefficients()

◆ ValidateTemperature()

◆ ValidateVoltage()