Clock without using RTC in Arduino with Temperature and humidity indicator

Project Description:

This small code will act as a clock and will also display the temperature and humidity using the DHT11 temperature and humidity Module. I used 3 buttons to set the clock.

Using Materials

Breadboard
Potentiometer
Some jumper wires
Arduino Uno BoardButton x3
LCD 1602 Module (With pi header)
DHT11 Temperature and Humidity Module

Clock without using RTC in Arduino with Temperature and humidity indicator

Schematic Diagram

Program Code:

// Ahmad Ordikhani Seyedlar

#include <LiquidCrystal.h>
#include <SimpleDHT.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
volatile int sec, minute = 0, hour = 0;
int b_h = 5;
int b_m = 6;
int pinDHT11 = 2;
int b_startstop = 3;
bool startstop = false;

SimpleDHT11 dht11;

void setup() {

// set up the LCD's number of columns and rows:
lcd.begin(16, 2);

lcd.setCursor(0, 0);
lcd.print("Ahmad Ordikhani");
lcd.setCursor(0, 1);
lcd.print("Clk without RTC");
delay(3000);
lcd.clear();

pinMode(b_h, INPUT_PULLUP);
pinMode(b_m, INPUT_PULLUP);
pinMode(b_startstop, INPUT_PULLUP);

attachInterrupt(digitalPinToInterrupt(3), buttons, FALLING);

}

void loop() {

//Setting the time will stop the clock to set the time
while (startstop == false)
{
lcd.setCursor(0, 1);
lcd.print("SET");
delay(100);
lcd.setCursor(0, 0);
lcd.print("Time: ");
if(hour<10)
{
lcd.print("0");
lcd.print(hour);
}
else
lcd.print(hour);

lcd.print(":");
if(minute<10)
{
lcd.print("0");
lcd.print(minute);
}
else
lcd.print(minute);
lcd.print(":");
if(sec<10)
{
lcd.print("0");
lcd.print(sec);
}
else
lcd.print(sec);
lcd.print(" ");

if (digitalRead(b_h) == LOW)
{
hour++;
if (hour > 23)
hour = 0;
}

if (digitalRead(b_m) == LOW)
{
minute++;
if (minute > 59)
minute = 0;
}

}

//Start the clock
while (startstop == true)
{

// noInterrupts();
// read with raw sample data.
byte temperature = 0;
byte humidity = 0;
byte data[40] = {0};
if (dht11.read(pinDHT11, &temperature, &humidity, data)) {
lcd.setCursor(0, 1);
lcd.print("Read DHT11 failed");
return;
}
lcd.setCursor(0, 1);
lcd.print("Temp:");
lcd.print((int)temperature);
//lcd.print("*C");
lcd.print(" ");
lcd.print("Hum.:");
lcd.print((int)humidity);
lcd.print("%");
//Serial.print((int)temperature); Serial.print(" *C, ");
// Serial.print((int)humidity); Serial.println(" %");

lcd.setCursor(0, 0);
//sec=millis()/1000;
delay(1000);
lcd.print("Time: ");
if (hour < 10)
{
lcd.print("0");
lcd.print(hour);
}
else
{
lcd.print(hour);
}
lcd.print(":");
if (minute < 10)
{
lcd.print("0");
lcd.print(minute);
}
else
{
lcd.print(minute);

} lcd.print(":");
if (sec < 10)
{
lcd.print("0");
lcd.print(sec);
}
else
{
lcd.print(sec);
}
lcd.print(" ");
//lcd.print(startstop);
sec++;
if (sec > 59)
{
minute++;
sec = 0;
//lcd.clear();
}

if (minute > 59)
{
hour++;
minute = 0;
//lcd.clear();
}
if (hour > 23)
{
hour = 0;
//lcd.clear();

}
}
}

//Start/Stop the clock
void buttons()
{
lcd.clear();
startstop = !startstop;

}