#define BLYNK_PRINT Serial

#define BLYNK_USE_DIRECT_CONNECT

#include <BlynkSimpleEsp32_BLE.h>
#include <BLEDevice.h>
#include <BLEServer.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "Your Auth Token";


#include <math.h>

int analog = 0;          //analog pin raw value
int V_0 = 3276;          //cirquit voltage [mV]
double V_R0 = 1;         //initial value of voltage devider[mV]
int circuit_R0 = 9800;  //resistance of voltage divider[ohm]

int thermo_B = 3380;     //B parameter of thermistor
int thermo_R0 = 10000;   //reference resistance of thermistor [ohm]
int thermo_T0 = 298;     //reference tempereture of thermistor[K]

double thermo_R = 1;     //initial resistance of thermistor[ohm]
double temp = 25.00;     //initial value of measured temperature[degC]

void setup () {

  Serial.println("Waiting for connections...");
  Blynk.setDeviceName("Blynk");
  Blynk.begin(auth);

  pinMode(34, INPUT);  // thermistor
  Serial.begin(9600);          /* 9600 bps connect serial */
  Serial.println("READ_START");    

}

void loop () {

  Blynk.run();

  analog = analogRead(34);
  V_R0 = analog * 3.28 / 4096 * 1000;                 //voltage divider calculation
  thermo_R = V_0 / V_R0 * circuit_R0 - circuit_R0; //thermistor resistance calculation
  Serial.println( analog);
  Serial.println( V_R0);
  Serial.println( thermo_R);                 //printing thermistor resistance

  temp = (1000 / (1 / (0.001 * thermo_T0) + log(thermo_R / thermo_R0) * 1000 / thermo_B) - 273); //temparature calculation

  Blynk.virtualWrite(V0, temp);

  Serial.println(temp, 1);                                                     //printing temparature

  delay(100);                      // waiting for 0.1s
}