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Topic: Defective LiquidCrystal.h with DUE (Read 2743 times) previous topic - next topic

Kuya Marc

Problem: Standalone LCD not possible

Hello! I may have discovered a serious defect with the default LiquidCrystal.h included with Arduino IDE 1.5.2. Unlike the AVR boards, the DUE can't use the LCD when it is not connected to a PC. What I mean to say is, it malfunctions when it does not have PC communications.


#include <LiquidCrystal.h>

LiquidCrystal lcd(7,8,9,10,11,12);

void setup() {
  lcd.begin(16, 2);
  lcd.print("hello, world!");

void loop() {
  lcd.setCursor(0, 1);

The undesirable effect is... A working LCD with useless data. Possible adjectives: garbled, scrambled.

Question: Is there a way to get the LCD to work on the DUE without have a computer connection?
I run Xubuntu Linux as my only computer operating system!
Windows does not run here; Only


Are you saying that the above code works if the USB cable is plugged in and doesn't if you remove the cable?

That loop will run much faster on a Due, maybe that's an issue but I cannot see how the USB connection would affect that. Anyway I'd add a delay() because writing to the LCD 100000 times a second is not good practice.

Rob Gray aka the GRAYnomad www.robgray.com

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