#include <WiFi.h>


#define THERMISTORNOMINAL 10000
#define TEMPERATURENOMINAL 25
#define BCOEFFICIENT 3950
#define SERIESRESISTOR 10000
#define ANALOG_PIN 35

const float TEMPERATURENOMINAL_DOUBLE = TEMPERATURENOMINAL * 2;

void setup() {
  Serial.begin(115200);
  analogReadResolution(12);  // ESP32 uses 12-bit ADC

  wifi_setup();
  
  // Print header for debugging
  Serial.println("ESP32 Thermistor Test");
  Serial.println("Raw ADC | Voltage | Resistance | Temperature");
}

void loop() {
  // Take multiple readings and average
  int sum = 0;
  for(int i = 0; i < 10; i++) {
    sum += analogRead(ANALOG_PIN);
    delay(10);
  }
  int reading = sum / 10;

  // Convert ADC to voltage
  float voltage = (float)reading * 3.3 / 4095.0;
  
  // Calculate resistance of thermistor
  float resistance;
  if(voltage != 0) {
    resistance = SERIESRESISTOR * ((3.3 / voltage) - 1.0);
  } else {
    resistance = 999999;
  }

  // Convert to temperature
  float steinhart;
  steinhart = resistance / THERMISTORNOMINAL;     // (R/Ro)
  steinhart = log(steinhart);                     // ln(R/Ro)
  steinhart /= BCOEFFICIENT;                      // 1/B * ln(R/Ro)
  steinhart += 1.0 / (TEMPERATURENOMINAL + 273.15); // + (1/To)
  steinhart = 1.0 / steinhart;                    // Invert
  steinhart -= 273.15;                            // Convert absolute temp to C

  steinhart *= -1;
  steinhart += TEMPERATURENOMINAL_DOUBLE;
  
  // Print all values for debugging
  Serial.print(reading);
  Serial.print(" | ");
  Serial.print(voltage, 3);
  Serial.print("V | ");
  Serial.print(resistance);
  Serial.print("Ω | ");
  Serial.print(steinhart);
  Serial.println("°C");
  
  delay(5000);
}



void wifi_setup() {
  Serial.print("Connecting to WiFi");
  WiFi.begin("Wokwi-GUEST", "", 6);
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
  }
  Serial.println(" Connected!");
}