LCD Dislay Problem

Dear all,

Here i M to trying uload the code mentioned in website on LCD . i have made connection as shown in below diagram. I found that there is no rint of hello world. The LCD Screen is just on. Can some one let me know what mistake i am doing,. I already checked connection twice.

LCD screen is Bright , there is no mark of helloworld. Programs uploaded mentioned in below link http://arduino.cc/en/Tutorial/LiquidCrystal

My current wiring is in this diagram http://oomlout.com/LCDD/LCDD-Guide.pdf

Let us check your wiring. Take a picture and attach it in your next post.

LarryD: Let us check your wiring. Take a picture and attach it in your next post.

Image is as exactly as forum link i have attached. Check PDF file attached with bread board connection

Did you adjust the contrast ?

Yes . i tried with varying contrstract is changing, Some time it remain constant not even vary. Is the wrirng is correct as mentioned in the PDF file. Or else some other mistake

I have to agree with LarryD . We need to see a photo of your wiring. With 389 posts I expect you have some experience breadboarding or wiring arduino circuits (some people say post count means nothing but sometimes it does). We're not going to ask twice. (I think I just did :D) Take a photo and post it. You're asking for our help and we need you to cooperate or we can't help you.

if you can figure out mistake well and good. Here variable resistor i replace with fixed resistor . Same thing happen when i attach variable resistor. Light is Always on

raschemmel: I have to agree with LarryD . We need to see a photo of your wiring. With 389 posts I expect you have some experience breadboarding or wiring arduino circuits (some people say post count means nothing but sometimes it does). We're not going to ask twice. (I think I just did :D) Take a photo and post it. You're asking for our help and we need you to cooperate or we can't help you.

As per you understanding image as i have attached,Let me know What i need to do.The reason for i never i want to put photo, It is very Difficult to catch u wire connection in image,

i found one problem Here. If i give 5v power supply through Arduino board . LCD light not blinks. But The Same power given @ the in no 15 and 16 i.e End pins of LCD module. LCD start blink. Now can you let me Know whats problem is????

It is very Difficult to catch u wire connection in image,

It does if you don't know how to wire a circuit for a photo. We do it all the time. When we say "take a photo" , we don't mean just grab a camera and snap a shot. What we mean is REWIRE your circuit in such a way that when you see it in a photograph , you can follow the wires. We can't really do that with your photo because the photo needs to be taken FROM DIRECTLY ABOVE so we can trace the wires. The wires should be as short as possible to make it easier to follow. Your problem may be that you don't have the right library but we can't tell because you have not posted your code or the compiler output. Go to "File\Preferences" and turn ON verbose output. Then put the mouse cursor over the red compiler output text and press Control-A. This will highlight ALL of the compiler output. Then press Control-C. This will COPY it. Then open Notepad and place the mouse curson in the Notepad window and press Control-V to paste it into Notepad. If you are using a Mac system someone else will have to tell you how to do that.

Go to "File\Preferences" and turn ON verbose output. Then put the mouse cursor over the red compiler output text and press Control-A. This will highlight ALL of the compiler output. Then press Control-C. This will COPY it. Then open Notepad and place the mouse curson in the Notepad window and press Control-V to paste it into Notepad. If you are using a Mac system someone else will have to tell you how to do that.

What is meant by red compiler output indicate Here

I done my wiring as per format given. I also attached with labelling.

What is meant by red compiler output indicate Here

The Arduino IDE (which version are you using ?) has an upper window and a lower window. When you load a program, the lower window has a combination of white text and red text. Compiler errors are always in red text, but even if there are no errors there is still some text in red in the lower window, like data hex values and other information. I don't know why some text is red but that information can be helpful even if there are no errors.

My recommendation is to disconnect everything and start over. Here is my generic step by step approach that should work:

(1) If the module has a backlight then get it working properly. This involves only pins 15 and 16 on your LCD module. Make sure to use a current limiting resistor if there is none on the LCD module.

(2) Get the power and contrast working properly. This involves only pins 1, 2, and 3 on your LCD module. You should be able to see blocks on one row of a two row display and on two rows of a four row display.

NOTE: The Arduino has not been used yet, except as a possible source for the power needed for the first two steps. Do not try to go any further until this is working. If you don't see the blocks then no amount of program code will help.

(3) Connect the LCD R/W pin (pin 5) to GND.

(4) Connect the six control and data wires between your LCD module and your Arduino.

(5) Upload your sketch and it should work.

If you still don't get a display then make sure that your wiring matches the numbers in the descriptor (or vice versa).

Code:

//LiquidCrystal lcd(RS, E, D4, D5, D6, D7); LiquidCrystal lcd(7, 8, 9, 10, 11, 12); // put your pin numbers here

If you get a display but it is garbled or has some other problems then try again with a 'static' sketch, one that displays a simple message on the top row of the display and then stops. All of your code should be in setup() and loop() should be empty between the brackets.

If you are still having problems then we need to see a photograph of your setup that clearly and unambiguously shows all of the connections between your Arduino and your LCD module. We also need a copy/paste version of the code that you are actually using, not a link to the code that you think you are using.

Don

floresta: My recommendation is to disconnect everything and start over. Here is my generic step by step approach that should work:

(1) If the module has a backlight then get it working properly. This involves only pins 15 and 16 on your LCD module. Make sure to use a current limiting resistor if there is none on the LCD module.

This is working fine For me (2) Get the power and contrast working properly. This involves only pins 1, 2, and 3 on your LCD module. You should be able to see blocks on one row of a two row display and on two rows of a four row display.

I could not able to adjust the contrast . If add resisror network it fine like voltage divider circuit .

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I could not able to adjust the contrast .

Until you get the contrast working you can go no further. Without knowing which display you are using we cannot offer any more specific help.

If add resisror network it fine like voltage divider circuit .

Try rephrasing this.

Don

Can you get a multimeter to measure the Contrast pin voltage ? For the contrast voltage, the best combination of resistors for a voltage divider is a 10 k resistor connected to +5V in series with a 1 k resistor connected to ground. The point where they connect in the middle should be 0.4 to 0.8V dc, which should be perfect voltage for contrast pin Vo (3).

Thanks For support Being Provided . Its Started Working now