/**
  Basic NTC Thermistor demo
  https://wokwi.com/arduino/projects/299330254810382858

  Assumes a 10K@25℃ NTC thermistor connected in series with a 10K resistor.

  Copyright (C) 2021, Uri Shaked
*/



const float BETA = 3950; // should match the Beta Coefficient of the thermistor
int DELAY_MS = 50; // 1000ms/50ms = 20Hz

// Va0 = Vdd/(Rt+R4) * R4
// R4 = Rt = 10k
// Va0 = 5/(10k+10k) * 10k = 2.5V ~ 512 value

// Rt = 5k
// R4 = 10k
// Va0 = 5/(5k+10k) * 10k = 3.33V

void setup() {
  Serial.begin(9600);
}

void loop() {
  int analogValue = analogRead(A0);
  Serial.print("Analog value: ");
  Serial.print(analogValue);
  Serial.print(" - ");

  float celsius = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
  Serial.print("Temperature: ");
  Serial.print(celsius);
  Serial.println(" ℃");
  delay(DELAY_MS);
}



termoresistor.ino

diagram.json

/*
  Blink

  Turns an LED on for one second, then off for one second, repeatedly.

  Most Arduinos have an on-board LED you can control. On the UNO, MEGA and ZERO
  it is attached to digital pin 13, on MKR1000 on pin 6. LED_BUILTIN is set to
  the correct LED pin independent of which board is used.
  If you want to know what pin the on-board LED is connected to on your Arduino
  model, check the Technical Specs of your board at:
  https://www.arduino.cc/en/Main/Products

  modified 8 May 2014
  by Scott Fitzgerald
  modified 2 Sep 2016
  by Arturo Guadalupi
  modified 8 Sep 2016
  by Colby Newman

  This example code is in the public domain.

  https://www.arduino.cc/en/Tutorial/BuiltInExamples/Blink
*/

/*

// vars
int RED_LED = 2;
int GREEN_LED = 3;
// 1000 = 1Hz
// 100 = 10Hz
//...
int DELAY_MS = 1000; // 1000ms/50ms = 20Hz


// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(RED_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(RED_LED, HIGH);   // turn the LED on (HIGH is the voltage level)
  digitalWrite(GREEN_LED, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(DELAY_MS);                       // wait for a second
  digitalWrite(RED_LED, LOW);    // turn the LED off by making the voltage LOW
  digitalWrite(GREEN_LED, LOW);   // turn the LED on (HIGH is the voltage level)
  delay(DELAY_MS);                       // wait for a second
}

*/

led_blink.ino

/*
#define ntc_pin A0         // Pin, to which the voltage divider is connected
#define vd_power_pin 2        // 5V for the voltage divider
#define nominal_resistance 10000       //Nominal resistance at 25⁰C
#define nominal_temeprature 25   // temperature for nominal resistance (almost always 25⁰ C)
#define samplingrate 5    // Number of samples
#define beta 3950  // The beta coefficient or the B value of the thermistor (usually 3000-4000) check the datasheet for the accurate value.
#define Rref 10000   //Value of  resistor used for the voltage divider
int samples = 0;   //array to store the samples

void setup(void) {
pinMode(vd_power_pin,OUTPUT);
 Serial.begin(9600);  // initialize serial communication at a baud rate of 9600
}

void loop(void) {
  uint8_t i;
  float average;
  int sample = 0;
  // take voltage readings from the voltage divider
  digitalWrite(vd_power_pin,HIGH);
  for (i=0; i< samplingrate; i++) {
   samples += analogRead(ntc_pin);
   delay(10);
  }
  digitalWrite(vd_power_pin,LOW);
  average = 0;
  average = samples/ samplingrate;
  Serial.print("ADC readings ");
  Serial.println(average);
  // Calculate NTC resistance
  average = 1023 / average - 1;
  average = Rref/ average;
  Serial.print("Thermistor resistance ");
  Serial.println(average);
 
  delay(1000);
}
*/