Melzi/Sanguino ATMEGA 1284P 16Mhz I2C LCD 20x4

Does anyone ever made a I2C LCD 20x4 successfully work on Melzi or Sanguino with ATMEGA 1284P 16MHz?

I connected mine on the pins SDA/SCL/+5V/GROUND of the Melzi board but I can't make it work. It turns on when powered, of course, but does not display anything.

I don't know what's wrong. Maybe the LCD uses a different I2C address on the Melzi? I'm connecting thre wrong pins? I have no clue...

That same LCD display works perfectly using the address 0x27 on an Arduino UNO R3 board. This is the code I'm uploading to the Melzi and to the Arduino to test it:

//I2C LCD Test

#include Wire.h
#include LiquidCrystal_I2C.h

LiquidCrystal_I2C lcd(0x27,20,4);  // set the LCD address to 0x27 and a 20 chars and 4 line display

void setup()
{
  lcd.init();                      // initialize the lcd 
  // Print a message to the LCD.
  lcd.backlight();
  lcd.setCursor(3,0);
  lcd.print("Hello, world!");
}
void loop()
{
}

I attached some pictures of the Melzi 1284p with the wired LCD. Please take a look.

Thank you,

Richard







Edited 9 time(s). Last edit at 03/22/2013 01:37AM by imgartchen.

The only one I have seen is at think3dprint3d.com the panelolou

Which firmware are you using?
I understand that Repieter and Marlin firmware but have the capability to drive LCD screens/switches.

I have also read that the Melzi does not have enough spare pins to do this, although the guy who has produced the Panelolu2 seems to have got it working...[blog.think3dprint3d.com]

Please update the thread if you get any success, it is something I am looking into doing at some point :-)

good luck
Phil