Project II - 17. Digital Thermometer Bar Graph using LCD (Arduino Based)

Digital Thermometer Bar Graph using LCD

Reading the temperature value with LM35 sensor then the result is displayed in bargraph form on LCD 2x16 with Arduino UNO as its data processor.

Hardware Requirement

• Temperature Sensor LM35
• Arduino UNO
• LCD 2x16 Module
• Power supply +5 Volt

LM35 Temperature Sensor | Source

Schematic

Source Code/Sketch

#include <LiquidCrystal.h>
LiquidCrystal lcd(2, 3, 4, 5, 6, 7);
unsigned int adc,tempLM,a,b,i;
byte bargraph1[8] = {
0b10000,
0b10000,
0b10000,
0b10000,
0b10000,
0b10000,
0b10000,
0b10000
};
byte bargraph2[8] = {
0b11000,
0b11000,
0b11000,
0b11000,
0b11000,
0b11000,
0b11000,
0b11000
};
byte bargraph3[8] = {
0b11100,
0b11100,
0b11100,
0b11100,
0b11100,
0b11100,
0b11100,
0b11100
};
byte bargraph4[8] = {
0b11110,
0b11110,
0b11110,
0b11110,
0b11110,
0b11110,
0b11110,
0b11110
};
byte bargraph5[8] = {
0b11111,
0b11111,
0b11111,
0b11111,
0b11111,
0b11111,
0b11111,
0b11111
};
// suhu : 0 - 100
// bar : 15x5 = 50
//============================================
void setup(void) {
lcd.begin(16, 2);
lcd.createChar(1, bargraph1);
lcd.createChar(2, bargraph2);
lcd.createChar(3, bargraph3);
lcd.createChar(4, bargraph4);
lcd.createChar(5, bargraph5);
lcd.print("Digital Therm");
lcd.setCursor(0,1);
lcd.write(byte(1));
delay(1000);
lcd.clear();
lcd.print("Dig Thermo 0-75C");
}
//===========================================
void loop(void) {
adc = analogRead(0);
tempLM=(adc*5)/10;
lcd.setCursor(0,1);
if(tempLM>5){
a=tempLM/5;
b=tempLM%5;
for(i=0;i<a;i++){
lcd.write(5);
}
if(b==1){
lcd.write(1);
}
else if(b==2){
lcd.write(2);
}
else if(b==3){
lcd.write(3);
}
else if(b==4){
lcd.write(4);
}
}
delay(2000);
}

How it Works

1. Connect the Arduino with Peripherals needed
2. Plug in the Power Source on the device
3. Compile and upload the script program above to your arduino

4. On the LCD will show the temperature value read by Arduino with LM35 temperature sensor with 

    bargraph display. 

5. If the temperature changes, the display on the LCD (long - short bargraph) will follow. The value 

    of 1 column = 10°C, so if 1 full box (5 columns) means 50°C.


Video for Project II - 17. Digital Thermometer Bar Graph using LCD (Arduino Based)

Download the required file.