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Changelog

What changed in each release of the driver. Entries marked BREAKING need source changes in code that used the affected API.

Unreleased

Breaking changes

  • BREAKING (behaviour): NTC::Constants::STEINHART_HART_A_, _B_ and _C_, used by NTC::ConvertResistanceToTemperatureDefault() and NTC::ConvertTemperatureToResistanceDefault(), are now the NTCG163JF103FT1S fit through spec sheet Table 3 at −40 °C, 25 °C and 125 °C (0.8767633 × 10⁻³, 2.527899 × 10⁻⁴, 1.906681 × 10⁻⁷). The old generic values read 9.4 °C low at 85 °C for this part. Code that relied on the old values for another thermistor must pass its own coefficients.

Documentation

  • The documentation site moved to the HardFOC MkDocs platform: new page set (quickstart, hardware, conversion methods, architecture, API guide, configuration, porting, examples, troubleshooting), the Doxygen API reference under /api/, and every code sample compiled by the host build from tests/docs/.
  • Added the TDK NTCG163JF103FT1S spec sheet and corrected the part facts: operating range −40 °C to +150 °C, B25/85 = 3435 K ± 1 %, 100 mW rated power. The documentation now states the Beta equation's error against the datasheet table and that the driver needs C++20.

Fixed

  • The NTCG163JF103FT1S lookup table now holds the spec sheet's Table 3 nominal resistances in ohms, −40 °C to +150 °C in 5 °C steps (it held values that were neither ohms nor this part's curve, including negative ones). The search and the validation follow the falling resistance of an NTC, and interpolation is linear in ln(R). NtcConversionMethod::LookupTable now reads the datasheet temperature at every row instead of falling back to the Beta equation.
  • Steinhart-Hart helpers: NTC::CalculateSteinhartHartCoefficients() solved the 3 × 3 system with a wrong determinant (in float) and returned no usable fit; it now solves it in closed form in double precision. NTC::ValidateSteinhartHartCoefficients() rejected C above 1 × 10⁻⁷, which excluded this part's fit (C = 1.9 × 10⁻⁷); it now accepts |C| up to 1 × 10⁻⁶ and rejects non-finite values. NTC::ConvertTemperatureToResistanceSteinhartHart() dropped the C term; it now solves the cubic exactly.
  • Calibrate() replaced the offset with reference − reading, but the reading already included the old offset, so calibrating with a non-zero offset left the sensor off by that offset. It now adds the correction to the existing offset. Calling ResetCalibration() first, as the docs advised, gives the same result as before.
  • sample_delay_ms was a busy-wait loop that the compiler could remove, so it waited an unknown time or none. The driver now waits through an optional DelayMs(uint32_t ms) hook on the ADC port, detected at compile time; a port without it takes the samples back to back. Existing ports compile unchanged.

  • NTC::CalculateOptimalSeriesResistance() and NTC::CalculateTemperatureAccuracy() used B = 3435 K whatever the part. New overloads take R25 and B (from ntc_config_t); the accuracy estimate is now the worst-case error from the R25 and B tolerances, which reproduces the spec sheet's Table 3 Min/Max band (0.26 °C at 25 °C, 1.1 °C at 85 °C) instead of a fixed-divisor approximation.

  • GetNtcThermistorDriverVersion() returned an empty string: the build settings never set HF_NTC_THERMISTOR_VERSION_STRING, which ntc_thermistor_version.h.in uses. It now returns "1.0.0".

  • The ESP32 example used a simulated ADC that returned a fixed mid-scale count, and B = 3950 K. It now reads the ESP32-C6 ADC through examples/esp32/main/esp32_ntc_adc.hpp (adc_oneshot with adc_cali calibration and a DelayMs() hook), configures the NTCG163JF103FT1S (B25/85 = 3435 K) with the lookup table, and tests a real reading. mock_esp32_adc.hpp is removed.

Deprecated

  • NTC::CalculateOptimalSeriesResistance(r25, t_min, t_max, &r) and NTC::CalculateTemperatureAccuracy(r, tol_r, tol_b, &acc): they assume the default part (R25 = 10 kΩ, B = 3435 K). Use the overloads that take B (and R25).

Added

  • CMake install() rules: the library, the headers with src/ntc_thermistor.ipp, the generated version header and an exported package, so find_package(hf_ntc_thermistor) and hf::ntc_thermistor work from an install prefix. hf::ntc_thermistor is also an alias in the build tree. The package configuration no longer includes the build-settings file, which was not installed.

  • Host unit tests (HF_NTC_THERMISTOR_BUILD_TESTS) that run the driver against a model of the ADC and divider and check readings against the NTCG163JF103FT1S resistance table.