Skip to main content

LM35

Interfacing LM35 Temperature Sensor with PIC Microcontroller.


The are many cool sensors available now a days, ranging from IR distance sensor modules, accelerometers, humidity sensors, temperature sensors and many many more(gas sensors, alcohol sensor, motion sensors, touch screens). Many of these are analog in nature. That means they give a voltage output that varies directly (and linearly) with the sensed quantity. For example in LM35 temperature sensor, the output voltage is 10mV per degree centigrade. That means if output is 300mV then the temperature is 30 degrees. In this tutorial we will learn how to interface LM35 temperature sensor with PIC18F4520 microcontroller and display its output on the LCD module.
First I recommend you to go and read the following tutorial as they are the base of this small project.
After reading the ADC tutorial given above you will note the the PIC MCU’s ADC gives us the value between 0-1023 for input voltage of 0 to 5v provided it is configured exactly as in the above tutorial. So if the reading is 0 then input is 0v, if reading is 1023 then input is 5v. So in general form if the adc read out is valthen voltage is.
unsigned int val;
val=ADCRead(0); //Read Channel 0
voltage= ((val)/1023.0)*5;
The above formula give voltage in Volts, to get Voltage in mili Volts (mV) we must multiply it with 1000, so
voltage=((val)/1023.0)*5*1000); //Voltage is in mV
since 10mV = 1 degree, to get temperature we must divide it by 10, so
t=((val)/1023.0)*5*100); //t is in degree centigrade
simplifying further we get
t=((val/1023.0)*500);
t=(val*0.48876);
we round off this value, so
t=round(val*0.48876);
remember round() is a standard c library function



Comments

Post a Comment

Popular posts from this blog

garbage monitoring using arduino code with gsm

#include <SoftwareSerial.h> #include <LiquidCrystal.h> //LiquidCrystal lcd(7, 6, 5, 4, 3, 2); LiquidCrystal lcd(13, 12, 11, 10, 9, 8); SoftwareSerial mySerial(0,1); #define trigPin 2 #define echoPin 3 #define PIR_sensor 4 #define m11 5 #define m12 6 void setup() {    lcd.begin(16, 2);    lcd.print("    Garbage    ");    Serial.println("garbage ");   lcd.setCursor(0,1);   lcd.print("   Open Close    ");   Serial.println(" open close");   delay(3000);   lcd.clear();   //lcd.print(" ");   delay(2000); mySerial.begin(9600); // Setting the baud rate of GSM Module Serial.begin (9600); pinMode(trigPin, OUTPUT); pinMode(echoPin, INPUT);  pinMode(m11, OUTPUT);   pinMode(m12, OUTPUT);   } void loop() {  readPIR();  pingDist();  SendMessage(); } void pingDist ()   {     long duration, distance;...
Post a Comment
Read more

PUNCHING MACHINE

ACCIDENT AVOIDING SYSTEM FOR PUNCHING MACHINE SYNOPSIS The aim of our project is to take a system-wide approach to preventing the machine accident. The system includes not just the machine and the operator; but rather, it includes everything from the initial design of the machine to the training of everyone that is responsible for any aspect of it, to the documentation of all changes, to regular safety audits and a finally a corporate culture of safety-first. Design is the part of a machine's life where the greatest impact can be made in relation to avoiding accidents. The designer should ensure that the machine is safe to set up and operate, safe to install, safe to maintain, safe to repair, and safe to decommission. Although safe operation is usually at the forefront of a designer's mind, safe maintenance and repair should also be a high priority. Around 50% of fatal accidents involving industrial equipment are associated with maintenance activities, and design...
Post a Comment
Read more