Problem with lighting lcd 20x4

Hello, I have to connected my arduino uno to an lcd 20x4 display. every conexion is correct but when I try to see my program there are some marks which prevent me to read correctly. I have tried with another simply program and it works perfectly. I can’t find my programation error. Can someone help me?

This is you want to correct it.

#include <LiquidCrystal.h>
LiquidCrystal lcd(7,6,5,4,3,2);

int pulsadormax = 13;
int pulsadormin = 12;
int tempmax;
int tempmin;
int temperatura;

void setup ()
{
pinMode (pulsadormax, INPUT);
pinMode (pulsadormin, INPUT);
tempmax = 0;
tempmin = 40;
}

void loop ()
{
temperatura = analogRead (0);
temperatura = (5.0temperatura100.0)/1024.0;

if (temperatura < tempmin)
{
tempmin = temperatura;
}
else if (temperatura > tempmax)
{
tempmax = temperatura;
}
if (digitalRead (pulsadormax) == HIGH)
{
lcd.begin (20,4);
lcd.setCursor (1,1);
lcd.print (“Temperatura Maxima”);
lcd.setCursor (7,3);
lcd.print (tempmax);
lcd.print (" Celsius");
}
else if (digitalRead (pulsadormin) == HIGH)
{
lcd.begin (20,4);
lcd.setCursor (2,1);
lcd.print (“Temperatura Minima”);
lcd.setCursor (7,3);
lcd.print (tempmin);
lcd.print (" Celsius");
}
else
{
lcd.begin (20,4);
lcd.setCursor(2,0);
lcd.print(“DISPLAY LCD 4x20”);
lcd.setCursor(6,1);
lcd.print(“Proyecto”);
lcd.setCursor(4,2);
lcd.print(“Temperatura”);
lcd.setCursor(0,3);
lcd.print(“by Javier y Virgile”);
}
}

Thank you.

First: Go back and modify your posting, highlight the code section and use the "code" icon above ([ # ]) to mark it up as code so we can read it more easily.

Second: Post a picture of the display showing the actual problem - and all your wiring - in sharp focus (as it is quite useless otherwise) and resolution no more than 1024 by 768

Hi Baramril

You said

I have tried with another simply program and it works perfectly

Which implies that you have run another program and got good results.

I'd recommend you upload that program again and double check that its definately still working and that you do not have a loose or intermittent connection.

If that still works fine, I'd check your code, especially the LCD setup etc to make sure you are specifying the same pins in both programs

i.e

LiquidCrystal lcd(7,6,5,4,3,2);

OK, so I didn't read the code!

"LCD.begin" only ever goes in setup - once!