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Author Topic: [Help] Conect LCD Display with PCF8574  (Read 3068 times)
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Hi, i'm trying to connect a PCF8574 with a display and control it with arduino UNO.
i've read some tutorials but nothing is showing in the lcd only light up backlight... i'm using proteus to simulate...
i've downloaded LiquidCrystal_I2C.h library but its not helping...
that is a picture of the connections:


I'm Using the Hello World example:
Code:
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(32,16,2);  // set the LCD address to 0x20 for a 16 chars and 2 line display

void setup()
{
  lcd.init();                      // initialize the lcd
 
  // Print a message to the LCD.
  lcd.backlight();
  lcd.print("Hello, world!");
}

void loop()
{
}

anyone know what is happing? thanks
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My virtual crystal ball says that you might try running a virtual I2C port scanner on your virtual I2C device.

What does your teacher say about this?


Don
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your circuit is wrong!

The lines A0..A2 is to set the I2C address of the PCF8574 not the control lines for the RS/RW/EN pins of LCD

Also if your LCD follows the HD44780 standard, do the following:
1) connect P0 to RS, P1 to E and set RW to GND (90% of cases you don't need read anything from LCD)
2) connect P4 to D4;P5 to D5, P6, to D6, and P7 to D5
3) set A0, A1, A2 to GND this will make the I2C slave address of PCF8574=0x20 (or if you are using PCF8574A=0x38)

Good luck!
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Mauricio M!
AVR/PIC/C8051F/LPC
"All I ever wanted
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Is here in my ARMs"

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IHi, i'm trying to connect a PCF8574 with a display and control it with arduino UNO.
i've read some tutorials but nothing is showing in the lcd only light up backlight... i'm using proteus to simulate...
that is a picture of the connections:
I'm Using the Hello World example:

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

LiquidCrystal_I2C lcd(0x20,16,2);
void setup()
{
  lcd.init();                     
  lcd.backlight();
  lcd.print("Hello, world!");
}

void loop()
{
}


* Sans titre.png (40.19 KB, 1016x452 - viewed 298 times.)
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