White on Blue 20x4 LCD Module breadboard schematic and sketch?

I recently recieved an LCD for the Arduino for Christmas, and I'm trying to figure out how to use it. It did not come with any header pins or manuals, and the person who sent it can't find where they bought it from. Pictures:



Can I do this with a breadboard, jumper wires, resistors and an Arduino?

Smaller pictures with better focus would help enormously

Sorry, was using a phone to take pics. I will photoshop them down to size, and upload the new pics soon. Also, the code on the back of the display is 'J204A'

Can I do this with a breadboard, jumper wires, resistors and an Arduino?

Yes. You will also need a potentiometer in order to set the contrast. It is possible to get an acceptable display using resistors to set the contrast voltage but it is easier with a potentiometer.

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).

//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

Cameras can die?!?
Anyway, while waiting for my 5k pentiometer to get here, I started on another project. When it gets here, I will try this again. Also, thanks for the help!

By the way, if you 'PUT RESISTORS ON EVERYTHING' that could also be part of your problem.

Don

I try to put light resistors on most things, if that doesn't work then remove them. Even with people saying it's safe, I still can't trust it to not burn up.

If you are worried about excessive current, which is what resistors can be used to limit, then why did you order a 5K pot instead of the recommended 10K?

Your 5K will work just as well as a 10K as far as the LCD is concerned but it draws twice the current from your source which is your Arduino voltage regulator.

Don

floresta:
If you are worried about excessive current, which is what resistors can be used to limit, then why did you order a 5K pot instead of the recommended 10K?

Your 5K will work just as well as a 10K as far as the LCD is concerned but it draws twice the current from your source which is your Arduino voltage regulator.

Don

Oh. Luckily I can send it back, and get a 10k. I thought 5k would be good for an LCD, but then again it didn't come with a sheet with a potentiometer ammount.

JohnSmith41:
Anyway, while waiting for my 5k potentiometer to get here, I started on another project.

No reason to procrastinate, just start with a 470 ohm from Vo (pin 3) to ground and 10k from Vo to Vcc. Unless this display is pretty unusual, you should see the row of "blocks". If you do not, the potentiometer is unlikely to do a great deal better.

Ah, the one value resistor I don't have... :confused:
I do have 2 220ohm resistors, would that work? Also, VCC is AREF, right?

JohnSmith41:
Ah, the one value resistor I don't have...
I do have 2 220ohm resistors, would that work?

In series, makes 440 ohms, no problem.

JohnSmith41:
Also, VCC is AREF, right?

It might be, but operating the LCD has nothing to do with ARef, totally different matter. ARef relates to making measurements on analog inputs.

In respect of the LCD, Vcc is the 5V output from the Arduino board that you are presumably using to power the LCD.

just start with a 470 ohm from Vo (pin 3) to ground and 10k from Vo to Vcc.

I'm confused, do I connect 2 things to Vo?

I’m confused, do I connect 2 things to Vo?

Yes. Each resistor has one end connected to pin 3 (Vo) of the LCD. The other end of the smaller one goes to pin 1 (GND) and the other end of the larger one goes to pin 2 (+5v).

Don

Pin 1? Does that mean pin 1 on the LCD? I'm sorry for being a n00b at this, it's my first time connecting a display to my Arduino...

Pin 1? Does that mean pin 1 on the LCD? I'm sorry for being a n00b at this, it's my first time connecting a display to my Arduino..

.
Yes. Just as it says in step #2 of my outline in reply #3. Your Arduino (the only other component with pin numbers) does not come into consideration until after the contrast voltage is adjusted.

Don

It might be worth looking at an spi backpack Cats and Kittens Mark 2 for long distance connectivity over CAT 5 cable - #4 by system - Products and Services - Arduino Forum

Macchard