Displaying 2 different Arduino boards on the same display

Other Hardware 3rd Party Boards
1

Hellow everyone...i have a question if u cant hlep me.

I use Arduino UNO and MEGA boards.

I tryed to dipley on the same lcd_i2c a counter wich come from mega2560 and a temperature(dht11 sensor) from atmega328, both of them on different rows ofc. if i run them individual there is no problem...when i connect them together i get everything but only what i need no.

Connections are like this...MEGA and UNO 5V and GND are comune with LCD_I2C and from I2C the SCL and SDA are comune with slc and sda from MEGA and UNO

This is the code for UNO

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <dht.h>

dht DHT;

#define DHT11_PIN 2

LiquidCrystal_I2C lcd(0x3F, 20, 4);

byte grade[8]={
B00010,
B00101,
B00010,
B00000,
B00000,
B00000,
B00000,
};

void setup()
{
lcd.init();
lcd.backlight();
lcd.createChar (0,grade);
}

void loop()
{
int chk = DHT.read11(DHT11_PIN);
delay(100);

lcd.setCursor(0,2);
lcd.print("temperatura ");
lcd.print(DHT.temperature);
lcd.print(char(0));
lcd.print("C");

}

and for MEGA

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x3F, 20, 4);

int val =0;
int canter;

void setup()
{
Serial.begin(9600);

pinMode(0, INPUT);

lcd.init();
lcd.backlight();
lcd.setCursor(0,0);
lcd.print(" Nivel UNU ");
lcd.setCursor(0,1);
lcd.print(" Nivelul DOI ");

}

void loop()
{
int nr = digitalRead(0);
delay(100);

lcd.setCursor(0,3);
lcd.print(" Credit ");
lcd.print(canter);
lcd.print("RON");

if(nr==0)
{
canter = canter +1;
Serial.print(" Credit curent= ");
Serial.println(canter);
}

delay(20);

}

PS: Im new on your website and i use arduino from a short period of time...and sorry for my bad English :smiley: