A simple node.js script for reading temperatures via Arduino Serial port.

serialTemp.js

var SerialPort = require('serialport');

var port = new SerialPort("/dev/ttyACM0", {
    baudRate: 9600,
    parser: SerialPort.parsers.readline('\n')
});

port.on('data', function(data) {
    console.log("%d Degrees C", data);
});

TMP36Reader.c

//
// Source adapted slightly from https://learn.adafruit.com/tmp36-temperature-sensor/using-a-temp-sensor.
//

//TMP36 Pin Variables
int sensorPin = 0; //the analog pin the TMP36's Vout (sense) pin is connected to
                        //the resolution is 10 mV / degree centigrade with a
                        //500 mV offset to allow for negative temperatures
 
/*
 * setup() - this function runs once when you turn your Arduino on
 * We initialize the serial connection with the computer
 */
void setup()
{
  Serial.begin(9600);  //Start the serial connection with the computer
                       //to view the result open the serial monitor 
}
 
void loop()                     // run over and over again
{
 //getting the voltage reading from the temperature sensor
 int reading = analogRead(sensorPin);  
 
 // converting that reading to voltage, for 3.3v arduino use 3.3
 float voltage = reading * 5.0;
 voltage /= 1024.0; 
 
 // now print out the temperature
 float temperatureC = (voltage - 0.5) * 100 ;  //converting from 10 mv per degree wit 500 mV offset
                                               //to degrees ((voltage - 500mV) times 100)
 Serial.println(temperatureC);
  
 delay(2000);                                     //waiting a second
}