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Temperature Sensor Using Arduino And RaspberryPi

Yash Thakur

Frontend Developer

Here we will connect an LM35 temperature sensor to Arduino and use its readings in RaspberryPi to monitor the temperature and send an email alert if the temperature is above 100. This can be used for safety as well as many places to get alerts of temperature variation.

Hardware used:

  • Arduino Uno
  • Raspberry Pi
  • Jumper Cables
  • Bread Board
  • LM35 (Temperature Sensor)
  • USB cable ( connecting Arduino to Raspberry Pi )

Steps :

  1. Connect Arduino to Arduino IDE and upload the below code to it.
  2. Connect your RaspberryPi and make a new file in terminal and write the below python code to it.
  3. Edit your username and passwords to it. (Note: If you are using Gmail kindly go to settings and allow less secure apps.
  4. Connect Arduino Uno to RaspberryPi using the USB cable.Connection of RaspberryPi and Arduino
  5. Run the python code in RaspberryPi.
  6. If the temperature is above 100 degrees Celcius an Email alert will be sent to the receiver.

Arduino code:

char dataString[50] = {0};
int val;
int tempPin = 1;
void setup() {
  Serial.begin(9600);              //Starting serial communication
void loop() {
  val = analogRead(tempPin);
  float mv = ( val/1024.0)*5000;
  float cel = mv/10;
  int cel1=(int)cel;
  sprintf(dataString,"%02X",cel1); // convert a value to hexa
  Serial.println(dataString);   // send the data
  delay(30000);                  // give the loop some break

RaspberryPi code:

import serial
import smtplib
ser = serial.Serial('/dev/ttyACM0',9600)
s = [0]
while True:
  temp = int (ser.readline(),16)
  s[0] = str(temp)
  print s[0]
  if temp > 100:
    server = smtplib.SMTP('smtp.gmail.com', 587)
    server.login("Sender Mail", "password")
    msg =s[0]+ "C Temperature Above Limit! Kindly Pay Attention!!!"
    server.sendmail("Sender Mail", "Receiver Mail", msg)
    print "Safe"