LCD not displaying characters

Projects General Guidance
1

I'm trying code Arduino UNO & 20x4 LCD with a very basic program as shown in last figure. But, its only displaying blank boxes. I'm pretty new at this so need some guidance.

Thank you

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2

It looks like you have a character LCD hooked up ..
i think that the lcd is not compatible with the library as :-
library supports only " The LiquidCrystal
library works with all LCD displays that are compatible with the
Hitachi HD44780 driver. There are many of them out there, and you
can usually tell them by the 16-pin interface." double check that the LCD is using the same driver that the library supports .....

3

Thank you so much for replying. But once again as its my first project i really don't know how to check if library is compatible.
This is a LCD fom FORDATA Electronics Co.,Ltd, China. It would be very great if you could please tell me which library can be used ?

Data sheet: http://docs-europe.electrocomponents.com/webdocs/0f25/0900766b80f25f62.pdf

Bought from: http://uk.rs-online.com/web/p/lcd-monochrome-displays/7200235/

4

can you tell me the serial no of the lcd
it is just printed on the back side of the lcd

5

once you should also try to change the wiring as follows :-

  • LCD RS pin to digital pin7
  • LCD Enable pin to digital pin 6
  • LCD D4 pin to digital pin 5
  • LCD D5 pin to digital pin 4
  • LCD D6 pin to digital pin 3
  • LCD D7 pin to digital pin 2
  • LCD R/W pin to ground
  • 10K resistor:
  • ends to +5V and ground
  • wiper to LCD VO pin (pin 3)

as you know that any pins can be used for displaying anything on an LCD Screen ....

6

I HIGHLY RECCOMEND YOU TO WATCH THE ADAFRUIT TUTORIAL FOR ARDUINO THE LINK IS :-

7

Serial: 2004BD1660Y

8

Your original arrangement and code appears to be quite correct. Don't bother about changing the pin numbers.

You have the contrast set more-or-less correctly, but the display is not being initialised. Something must be wrong with the connections.

As you have no LED to illuminate this display, you do not need to connect pins 15 and 16, so you may as well remove the connections to those so as not to confuse yourself.

I suggest you take down all the jumper wires, test all of those with a pin on each end using a LED and 330 ohm resistor on the breadboard which you connect using each of the jumpers (two at a time) and if they are all correct, carefully reassemble it according to your original diagram.

Actually, the jumper wires you already have connected to Vcc and ground and the potentiometer are clearly OK as they are - but I have to suspect there is either a faulty wire, a wire not properly inserted, or a wire to the wrong pin that I just cannot see in your photograph.

9

Thank you so much for you replies. i'll try and post back asap.

10

Today i have used a similar 20x4 LCD module 'FORDATA' and couldn't get it worked :/. How did you solve it at the end?

Thanks