TMP36_averaging.ino

/******************************************************************************
  TMP36_averaging.ino
  Written by Ho Yun "Bobby" Chan
  @ SparkFun Electronics
  Date: Nov 4, 2019
  
  Description: This sketch configures temperature sensor and prints the
  temperature in degrees celsius and fahrenheit. A sample set of data points
  are saved in an array and averaged in an attempt to smooth out readings.
  Simply adjust the `output_select` to view the °C, °F, or both. Open the 
  Serial Monitor or Plotter at 115200 baud to view the data.
  
  Development Environment Specifics:
  Arduino 1.8.9+
  
  License:
  This code is released under the MIT License (http://opensource.org/licenses/MIT)
  Distributed as-is; no warranty is given.
  
******************************************************************************/


//variables for TMP36
float tmp36_voltage = 0;                      //the voltage measured from the TMP36
float tmp36_degC = 0;                         //the temperature in Celsius, calculated from the voltage
float tmp36_degF = 0;                         //the temperature in Fahrenheit, calculated from the voltage
int increment = 100;                          //step size for averaging
float avg_degC[100];                          //array to help average reading
float avg_degF[100];                          //array to help average reading

//0 = output degrees °C
//1 = output degrees °F
//any other number = output degrees °C and °F
int output_select = 2; //select output

void setup() {
  Serial.begin(115200);    // Start serial communication at 115200 baud
  if (output_select == 0 ) {
    Serial.println("TMP36[°C]");
  }
  else if (output_select == 1) {
    Serial.println("TMP36[°F]");
  }
  else {
    Serial.print("TMP36[°C]");
    Serial.print(",");
    Serial.println("TMP36[°F]");
  }
}// end setup

void loop() {
  for (int i = 0; i < increment; i++) {
    //get TMP36 readings and calculate
    tmp36_voltage = analogRead(A0) * 0.004882814;   //convert the analog reading, which varies from 0 to 1023, back to a voltage value from 0-5 volts
    tmp36_degC = (tmp36_voltage - 0.5) * 100.0;     //convert the voltage to a temperature in degrees Celsius
    tmp36_degF = tmp36_degC * (9.0 / 5.0) + 32.0;   //convert the voltage to a temperature in degrees Fahrenheit
    avg_degC[i] = tmp36_degC;                       //save sample for averaging
    avg_degF[i] = tmp36_degF;                       //save sample for averaging
  }
  for (int j = 0; j < increment; j++) {
    if (j == 0) {
      tmp36_degC = 0;
      tmp36_degF = 0;                               //set value to 0 to calculate average
    }

    tmp36_degC = tmp36_degC + avg_degC[j];
    tmp36_degF = tmp36_degF + avg_degF[j];          //add data points

  }

  tmp36_degC = tmp36_degC / increment;
  tmp36_degF = tmp36_degF / increment;  //average temp after grabbing 100 data points

  if (output_select == 0 ) {
    // Print temperature in °C
    //Serial.print("Temperature in Celsius: ");
    Serial.println(tmp36_degC);//TMP36 temperature
  }
  else if (output_select == 1) {
    // Print temperature in °F
    //Serial.print("Temperature in Fahrenheit: ");
    Serial.println(tmp36_degF);

  }
  else {
    Serial.print(tmp36_degC);       //TMP36 temperature
    Serial.print(",");              //seperator
    Serial.println(tmp36_degF);
  }

  //delay(50); // Delay added for easier readings

}//end loop