How do I know if there's something in my lcd?

Projects Programming
1

Hi, I just wanted to know if exists any function that returns TRUE or FALSE if finds (or not) something written in my lcd.

2

If it's your LCD then surely you know whether you wrote to it or not.

3

Don't take any chances. There could be something hiding behind the backlight and you'd never know it. Insert lcd.clear(); at some point in your code at some point that it's not expected. That way, anything lurking in your LCD will be taken by surprise.

4

UKHeliBob:
If it's your LCD then surely you know whether you wrote to it or not.

Of course I know when the display shows something. I just want Arduino to know when the display is showing something... I don't know, maybe doing a digitalRead in D4, D5, D6 and D7.

5

Let me try again.
The Arduino wrote to the LCD because your program did it. Therefore the Arduino "knows" that something is on the LCD. Unless, of course, the Arduino did not write to the LCD and some other device did. In which case I would be interested to know how you have the devices connected.

LCDs often have a Read/Write pin but I have not seen a program that actually reads from the LCD but that is not to say that it is not possible.

6

Yes you should better write a good program that you know at witch moment it display something and when it does not, rather than try to find out if you already wrote something, that's strange :wink:
Hope to be clear, good luck 8)