Need TTL LCD connection advise

Other Hardware Displays
1

I have a Arduino 5V Pro Mini hooked to a 3 wire serial enabled LCD 16X2 from Sparkfun.

I am doing hello world..

I am programming with a cable and then unhooking and applying an independent 5V source.

Problem here is I am not sure what the data pin on the Pro Mini is supposed to be

/* Include the SPI/IIC Library */
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,16,2);

void setup() 
{
  lcd.init();
  lcd.init();
  lcd.backlight();
}

void loop() 
{
  lcd.setCursor(0,0); 
  lcd.print("Hello World");
  lcd.setCursor(0,1); 
  delay(3000);
  lcd.setCursor(0,1); 
  lcd.print(" Good Day.. ");
 delay(1000);
  lcd.setCursor(0,1); 
  lcd.print("           ");
}
2

Problem here is I am not sure what the data pin on the Pro Mini is supposed to be

I'm afraid that's the least of your problems. You need a totally different sketch, preferably one that uses the software serial library not an I2C library.

Have you considered following the Quickstart Guide on the page you linked to? It even tells you the answer to your question: "// Attach the serial display's RX line to digital pin 2"

Don

3

Boom, I don't know what I was thinking. I went back in and plugged in Softserial and away she went. Thanks.

R