#include <Arduino.h>
#include <math.h>

// Pin and resistor configuration
#define THERMISTOR_PIN 1        // Analog pin between the two resistors
#define SERIES_RESISTOR 100000   // 100k ohm fixed resistor
#define NOMINAL_RESISTANCE 10000 // NTC resistance at nominal temp (100k ohm)
#define NOMINAL_TEMPERATURE 25   // Nominal temperature in °C (usually 25°C)
#define B_COEFFICIENT 3950       // Beta coefficient of the NTC (adjust if needed)
#define ADC_MAX 4095             // 12-bit ADC (ESP32)
#define VCC 3.3                  // Supply voltage

void setup() {
  Serial.begin(115200);
  analogReadResolution(12); // Set ADC to 12-bit resolution
  Serial.println("NTC Thermistor Temperature Monitor");
  Serial.println("-----------------------------------");
}

void loop() {
  // Read the ADC value
  int adcValue = analogRead(THERMISTOR_PIN);

  // Convert ADC to voltage
  float voltage = adcValue * (VCC / ADC_MAX);

  // Calculate NTC resistance
  // Circuit: 3.3V -- [100k resistor] -- D8 -- [NTC] -- GND
  float ntcResistance = SERIES_RESISTOR * (voltage / (VCC - voltage));

  // Apply Steinhart-Hart equation (Beta version)
  float steinhart;
  steinhart = ntcResistance / NOMINAL_RESISTANCE;   // R/Ro
  steinhart = log(steinhart);                        // ln(R/Ro)
  steinhart /= B_COEFFICIENT;                        // 1/B * ln(R/Ro)
  steinhart += 1.0 / (NOMINAL_TEMPERATURE + 273.15); // + (1/To)
  steinhart = 1.0 / steinhart;                       // Invert
  float tempC = steinhart - 273.15;                  // Convert to Celsius
  float tempF = tempC * 9.0 / 5.0 + 32.0;           // Convert to Fahrenheit

  // Print results
  Serial.print("ADC: ");
  Serial.print(adcValue);
  Serial.print(" | Voltage: ");
  Serial.print(voltage, 3);
  Serial.print("V | NTC Resistance: ");
  Serial.print(ntcResistance / 1000, 2);
  Serial.print("kΩ | Temp: ");
  Serial.print(tempC, 2);
  Serial.print("°C / ");
  Serial.print(tempF, 2);
  Serial.println("°F");

  delay(1000); // Read every second
}
/*

**Circuit recap (matches your description):**
```
3.3V ── [100k Ω resistor] ── D8 ── [NTC 100k Ω] ── GND

*/