DS18B20 Temperature Sensor with LCD Display

Parts List

• Arduino UNO
• LCD display 16×2 with I2C
• DS18B20 Temperature Sensor
• 4.7k resistor

Wiring Arduino UNO + I2C LCD + DS18B20 Sensor

Upload Code to Arduino

#include <OneWire.h>
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);
// Addr, En, Rw, Rs, d4, d5, d6, d7, backlighpin, polarity

OneWire  ds(2);  // on pin 2 (a 4.7K resistor is necessary)

void setup() {
lcd.begin(16, 2);
lcd.backlight();
lcd.clear();
lcd.print("Temperature.....");
delay(3000);
lcd.clear();
lcd.print("Starting.....");
delay(3000);
}

void loop() {
byte i;
byte present = 0;
byte type_s;
byte data[12];
byte addr[8];
float celsius, fahrenheit;

if ( !ds.search(addr)) {
ds.reset_search();
delay(250);
return;
}
for ( i = 0; i < 8; i++) {
}
if (OneWire::crc8(addr, 7) != addr[7]) {
return;
}
// the first ROM byte indicates which chip
switch (addr[0]) {
case 0x10:
type_s = 1;
break;
case 0x28:
type_s = 0;
break;
case 0x22:
type_s = 0;
break;
default:
return;
}
ds.reset();
ds.select(addr);
ds.write(0x44, 1);        // start conversion, with parasite power on at the end
delay(1000);     // maybe 750ms is enough, maybe not
// we might do a ds.depower() here, but the reset will take care of it.
present = ds.reset();
ds.select(addr);
ds.write(0xBE);         // Read Scratchpad
for ( i = 0; i < 9; i++) {           // we need 9 bytes
data[i] = ds.read();
}
int16_t raw = (data[1] << 8) | data[0];
if (type_s) {
raw = raw << 3; // 9 bit resolution default
if (data[7] == 0x10) {
// "count remain" gives full 12 bit resolution
raw = (raw & 0xFFF0) + 12 - data[6];
}
} else {
byte cfg = (data[4] & 0x60);
// at lower res, the low bits are undefined, so let's zero them
if (cfg == 0x00) raw = raw & ~7;  // 9 bit resolution, 93.75 ms
else if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms
else if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms
//// default is 12 bit resolution, 750 ms conversion time
}
celsius = (float)raw / 16.0;
fahrenheit = celsius * 1.8 + 32.0;
lcd.clear();
delay(500);
lcd.setCursor(0, 0);
lcd.print("ELEC-CAFE.COM");
lcd.setCursor(0, 1);
lcd.print(celsius);
lcd.print(" C");
lcd.setCursor(9, 1);
lcd.print(fahrenheit);
lcd.print(" F");
delay(10000);
}

LCD Display Temperature from DS18B20

Check the temperature by LCD display with Arduino UNO and DS18B20 Sensor.