Dont show text

Hello guys,my lcd dont show text,but he turn on.

im using this circuit :

And this code:

#include <LiquidCrystal.h> 

#define Luz_Fundo  7


LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup()
{
lcd.begin(16, 2); // Iniciando o objeto "lcd" de 2 linhas e 16 colunas
pinMode(Luz_Fundo,OUTPUT); //define o pino como saída
digitalWrite(Luz_Fundo,HIGH); // Liga a luz do display.
}

void loop()
{
lcd.setCursor(0,0); 
lcd.print(" engenheirando! ");
lcd.setCursor(0,1); 
lcd.print("   ");
lcd.print(millis()/1000); 
}

We have to see a photograph of how you actually connected your circuit, not a picture of how you think you connected it.

If you are going to use the awful example in the LiquidCrystal tutorial as the basis for your program then you should follow it more closely. The information that never changes should be sent to the display in setup. This would be " engenheirando! " and " ". Only the information that changes should be sent in loop.

A better initial sketch would display only static information.

#include <LiquidCrystal.h>

//LiquidCrystal lcd(RS, E, D4, D5, D6, D7);
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);      // put your pin numbers here

void setup()
  {
  lcd.begin(16, 2);                          // put your LCD parameters here
  lcd.print("hello, world!");
  lcd.setCursor(0,1);
  lcd.print("it works!");
  }

void loop()
  {
  }

You are probably overstressing the circuitry behind I/O pin 7 by driving the backlight from that pin. Do you have any idea how much current is required by your backlight?

Don

Link to your LCD display?

I note you have “Vo” connected to ground.

In most cases, that should work, but it may need to be adjusted. Most circuits show a 10k potentiometer to do this but in fact in most cases, a single resistor of either 470 ohms or 1k from Vo to ground will be the correct value. You will know when you have a correct value when you clearly see a row of “blocks” in the first line if you connect power (or USB) to your UNO with the reset button held down.

floresta: You are probably overstressing the circuitry behind I/O pin 7 by driving the backlight from that pin. Do you have any idea how much current is required by your backlight?

He most probably isn't. As long as the board contains "R8" (or "R9") with a value of "101" or 100 ohms as most of the "cheapies" from eBay and other popular vendors do, and the backlight LED is itself white, it will be fine.

You saved me the critique of the code.

Hi.

I saw a lot of issues these lasts days with this kind of connection/code using 7/8 wires with 1602 LCDs. I used 2 times this connection, and even myself with good knowledge of electronic and skill for soldering, I got issue. So my advice, for less than 1 usdl, you can get a nice IIC/I2C/TWI/SPI Serial Interface Board Module. Easy to solder, and code is easy too. No more web wiring, and easier to identify problems.

I saw a lot of issues these lasts days with this kind of connection/code using 7/8 wires with 1602 LCDs. . .

And I have seen just as many issues concerning getting I2C adapters to work.

At any rate his question was about how to get his parallel interface running and that is what this thread is about.

Don