IoT Formulas Library

A C library with functions for common formulas used on embedded systems.

Characteristics

• Portable-ish: only double and float depending on the compilation, are not portable.
• Testable: 20+ tests.
• ESP-IDF support:
  • Component name: iot-lib-formulas.
  • Configurable: using menuconfig.

Functions For

• ADC
• Temperature
• Thermistor
• Voltage Divider

Documentation

Everything is at the docs folder.

Example: Calculate Temperature in ºC from Thermistor on a Voltage Divider

#include <stdio.h>
#include "iot_lib_formulas/voltage_divider.h"
#include "iot_lib_formulas/thermistor.h"
#include "iot_lib_formulas/temperature.h"

void app_main(void)
{
    float_type thermistor_resistance = volt_divider_resistive_calc_resistor_2(5.0,     // 5V in.
                                                                              10000.0, // 10K resistor 1
                                                                              2.5);    // 2.5V out.

    float_type kelvin = thermistor_calc_temperature_steinhart_betha(COMMON_THERM_PROBE_AMBIENT_TEMP_KELVIN,
                                                                    COMMON_THERM_PROBE_RESISTANCE,
                                                                    COMMON_THERM_PROBE_BETHA,
                                                                    thermistor_resistance);
    float_type celsius = CONV_KELVIN_CELSIUS(kelvin);

    prinft("Temperature: %f celsius", celsius);
}