My lcd keeps repeatedly printing stuff

Other Hardware Displays
1

i have 16x2 lcd and i have DS3231 rtc I'm using to make a clock and whenever i write lcd.print(rtc.hour()); it keeps repeatedly printing it like:17 18 19
the code is not finished yet though
and if i try it with a sketch that initialises the lcd and just prints hello world in void loop it works

#include "Arduino.h"
#include "uRTCLib.h"
#include <LiquidCrystal.h>

// uRTCLib rtc;
uRTCLib rtc(0x68);
int hour;
char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
bool night = false;
const int buttonPin = 7;
int buttonState = 0;
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
void setup() {
  lcd.begin(16, 2);
  Serial.begin(9600);
  delay(3000);// wait for console opening
  URTCLIB_WIRE.begin();
  pinMode(buttonPin, INPUT);


}

void loop() {
  rtc.refresh();
  lcd.setCursor(0,0);
  lcd.print(rtc.second());
  delay(1000);
 
}
2

Your sketch is printing seconds, not hours

  lcd.print(rtc.second());
3

i wrote some new code to display the time and the same thing keeps happening

#include "Arduino.h"
#include "uRTCLib.h"
#include <LiquidCrystal.h>

// uRTCLib rtc;
uRTCLib rtc(0x68);
int hour;
char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
bool night = false;
const int buttonPin = 7;
int buttonState = 0;
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
void setup() {
  lcd.begin(16, 2);
  Serial.begin(9600);
  delay(3000);// wait for console opening
  URTCLIB_WIRE.begin();
  pinMode(buttonPin, INPUT);

  // Comment out below line once you set the date & time.
  // Following line sets the RTC with an explicit date & time
  // for example to set January 13 2022 at 12:56 you would call:
   
  // rtc.set(second, minute, hour, dayOfWeek, dayOfMonth, month, year)
  // set day of week (1=Sunday, 7=Saturday)
}

void loop() {
  rtc.refresh();
  lcd.setCursor(0,0);
  lcd.print(rtc.hour());
  lcd.print(":");
  lcd.print(rtc.minute());
  lcd.print(":");
  lcd.print(rtc.second());
  delay(1000);
 
}

1689059385902
16890593859021920×1083 135 KB

4

As the name suggests, the loop() function is called repeatedly - in a loop.

The delay at the end of your code means it gets repeated every second.

It looks like the output from previous iterations is remaining on the screen - have you tried clearing the screen at the start of each loop?

5

Welcome

You use the same pin for the button and for the LCD Register Select (RS) pin. This will cause problems.

6

Try this code.
I changed the buttonPin pin to 8 and added a line to clear the LCD at the end after the 1 sec delay.

#include "Arduino.h"
#include "uRTCLib.h"
#include <LiquidCrystal.h>

// uRTCLib rtc;
uRTCLib rtc(0x68);
int hour;
char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
bool night = false;
const int buttonPin = 8;
int buttonState = 0;
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
void setup() {
  lcd.begin(16, 2);
  Serial.begin(9600);
  delay(3000);// wait for console opening
  URTCLIB_WIRE.begin();
  pinMode(buttonPin, INPUT);

  // Comment out below line once you set the date & time.
  // Following line sets the RTC with an explicit date & time
  // for example to set January 13 2022 at 12:56 you would call:
   
  // rtc.set(second, minute, hour, dayOfWeek, dayOfMonth, month, year)
  // set day of week (1=Sunday, 7=Saturday)
}

void loop() {
  rtc.refresh();
  lcd.setCursor(0,0);
  lcd.print(rtc.hour());
  lcd.print(":");
  lcd.print(rtc.minute());
  lcd.print(":");
  lcd.print(rtc.second());
  delay(1000);
  lcd.clear();
}
7

For a fuller presentation, "zero pad" your single digits

  if lcd.print(rtc_hour()) < 10
    lcd.print(0);
  lcd.print(rtc.hour());
  lcd.print(":");
  if lcd.print(rtc_minute()) < 10
    lcd.print(0);
  lcd.print(rtc.minute());
  lcd.print(":");
  if lcd.print(rtc_second()) < 10
    lcd.print(0);
  lcd.print(rtc.second());
8

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.