[SOLVED]LCD Liquid Crystal Display Screen only shows squares in top row

Other Hardware Displays
1

I am using an LCD Liquid Crystal Display Screen and doing the "Hello World" Tutorial Project. ( http://arduino.cc/en/Tutorial/LiquidCrystal )

However, no matter what, the screen only displays 16 solid squares instead of characters on the top row. I try turning the potentiometer connected but all it does is fade out the squares. Here is the circuit I'm using:

And the code:

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {

  lcd.begin(16, 2);
  lcd.print("hello, world!");
}

void loop() {
  lcd.setCursor(0, 1);
  lcd.print(millis()/1000);
}

Why is this happening? I am almost sure this can't be a code error. Is it a fault in my circuit or in the LCD board itself?

2

I'm having the exact same issue. However I have another similar LCD display at hand and that one shows the same issue, so apparently the display itself doesn't seem to be the problem, at least in my case.

I have built Crytsal ball project before and at time it worked fine...

3

ruud00000:
I'm having the exact same issue. However I have another similar LCD display at hand and that one shows the same issue, so apparently the display itself doesn't seem to be the problem, at least in my case.

I have built Crytsal ball project before and at time it worked fine...

Yeah. I was using the display for the Crystal Ball and it didn't work. Then I tried doing something simpiler like this "Hello World" project but I still have nothing. At least now I know it isn't something wrong with the screen itself.

4

Guys, really ?

There's a gazillion topics on this, right here.
Performing a search on the word "squares" will give lots of results, some on mathematics, some on shapes of electronic components, and lots on your problem.

Check your wiring.
Check each wire, prefab jumper wires aren't well known for their quality.
Then check your wiring again.
Have a look at the constructor in your LCD initialization, and then check the wiring against that.

I hope you get the message by now.

5

I have built Crytsal ball project before and at time it worked fine...

Well I don't have a crystal ball so you (both of you) will have to send photographs of your setup.

We will use the photograph(s) to check your wiring of course. We can also check out your soldering as well.

If you can see a row of boxes and you can vary their intensity with the potentiometer the your power and backlight connections are OK. That leaves just seven more connections to check out. Hint: one of them is black on the diagram above.

Don

6

Measuring all wires (allmost) the last one measured was actually a bad wire...

In case there's a connection with the display error pattern: it was the one connected to pin 12 (RS).

Thanks and good luck measuring (resistance of) all wires;-(

7

ruud00000:
Measuring all wires (almost) the last one measured was actually a bad wire...

A bad wire, eh? Was it just bad, or really evil? ]:slight_smile:

And the last one measured? That's like something for which you are searching always being in the very last place you look.

So, this "wire" was one of those "Dupont" jumpers from China, wasn't it?

You are nowhere near the first to come across one of those that wasn't internally connected. I don't know what is under the plastic moulding of the sort with a nice cylindrical finger grip, but clearly the crimp inside the ones with the snap-on sheaths doesn't always connect properly.

If it concerns me, I connect all the wires in a batch into a breadboard alternating back and forth between rows so they are all in series, and test the whole chain.

8

Hi,

I didn't buy them in China but from iprototype.nl but thay may well originate from China.

Can you advise where to buy better quality jumpwires or are they generally all bad quality. (BTW if bad is not the right word just tell what the correct word is, not everyone is native English speaking...).

9

Maak je geen zorgen, 'bad' is het juiste woord.

These wires are so cheap, you can't complain about a doa once in a while.
Just throw it away and go on.
Complaining and getting a replacement will cost you more.
The site you got them from is a well known source over here in the Netherlands, and very likely to get their stuff from China..
Just test the wires like Paul__B told immediately after you receive them and you're good to go.

10

... not everyone is native English speaking

You might want to go back and put some more information into your profile. You could even get rid of the alien icon next to your username at the same time.

Don

11

All my wires seem to function after testing it. Am I wiring something incorrectly?

  • Pictures not posted atm -
1 Like
12

The photo's are rather big for the forum, better attach them

13

robtillaart:
The photo's are rather big for the forum, better attach them

How do I do that?

14

It looks to me like you have R/W connected to the arduino and EN is not connected to anything. R/W (LCD pin 5) should connect to ground and EN (LCD pin 6) connects to the arduino.

15

groundfungus:
It looks to me like you have R/W connected to the arduino and EN is not connected to anything. R/W (LCD pin 5) should connect to ground and EN (LCD pin 6) connects to the arduino.

That's where I went wrong! Thanks so much!

16

It looks to me like you have R/W connected to the arduino and EN is not connected to anything. R/W (LCD pin 5) should connect to ground and EN (LCD pin 6) connects to the arduino.

I must be missing something. What are you looking at?

Don

17

There were pictures. OP must have removed them or I am dreaming again.

18

chummer1010:

robtillaart:
The photo's are rather big for the forum, better attach them

How do I do that?

When you post there is at the bottom a link "Additional Options" and it shows you attach menu

19

floresta:

It looks to me like you have R/W connected to the arduino and EN is not connected to anything. R/W (LCD pin 5) should connect to ground and EN (LCD pin 6) connects to the arduino.

I must be missing something. What are you looking at?

Don

groundfungus:
There were pictures. OP must have removed them or I am dreaming again.

Yeah. I removed them because you said they were too big, Don.

robtillaart:

chummer1010:

robtillaart:
The photo's are rather big for the forum, better attach them

How do I do that?

When you post there is at the bottom a link "Additional Options" and it shows you attach menu

Okay, thanks!

20

Yeah. I removed them because you said they were too big, Don.

That wasn't me and it wasn't anyone else either. You were asked to present them in a different manner, totally removing them is not a good idea. What we have now is just another fractured thread.

Don