Category: IOT

I’m taking a class on how to build Arduino devices.

This morning’s Arduino lesson used a temperature sensor to read the temperature and output it to the Arduino serial monitor.

Here is my Arduino code which is a combo of code from the class plus my attempt to integrate an alarm to it which I got from a combination of YouTube and Arduino online resources.

The code is my own creation based on stuff I found. 

It is free for you to use copy improve and share.  Enjoy!

Arduino Based Temperature Monitor Sample Code

int tempPin = A1; //Sets Analog Pin for Temp Sensor
int buzzer = 12; //Set alarm pin for peiezio sensor
int alertTemp = 78;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600); //Starts serial monitor output
  pinMode(buzzer,OUTPUT); //initialize the buzzer pin as an output
  }

void loop() {
  // put your main code here, to run repeatedly:
  int sensorVal = analogRead(tempPin); //Reads the temperature sensor
  float voltage = sensorVal * 5; //Turns sensrVal to Voltage
  voltage /= 1024; //Divides voltage by 1024 and sets voltage to that result
  float tempC = (voltage - .5) * 100; //Determines temp inCelsius from Voltage
  float tempF = (tempC * 9 / 5)  + 32; //Determines temp in Fahrenheit from Celsius
  
  /***************** Begin Loop for alarm if temp is above ***********************/
   unsigned char i; //define a variable
   if(tempF > alertTemp) {
    Serial.println(tempF); //Prints value of tempF variable anbd end line
    Serial.print("Celsius Temp: "); //Prints Title
    Serial.print(tempC);
    Serial.print(" Fahrenheit Temp: "); //Prints Title
    delay(1000); //delay for 1000 milliseconds
  
      //output an frequency
      for(i=0;i<80;i++) {
        digitalWrite(buzzer,HIGH);
        delay(1);//wait for 1ms
        digitalWrite(buzzer,LOW);
        delay(1);//wait for 1ms;
       }
      //output another frequency
      for(i=0;i<100;i++){
        digitalWrite(buzzer,HIGH);
        delay(2);//wait for 2ms
        digitalWrite(buzzer,LOW);
        delay(2);//wait for 2ms;
       }
   }
   else {
    digitalWrite(buzzer,LOW);
   }
  /***************** End Loop for alarm if temp is above ***********************/
  
  Serial.println(tempF); //Prints value of tempF variable and end line
  Serial.print("Celsius Temp: "); //Prints Title
  Serial.print(tempC);
  Serial.print(" Fahrenheit Temp: "); //Prints Title
  delay(1000); //delay for 1000 milliseconds
}