Controlling a Character LCD With an Arduino

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About: I'm a software developer, but I also love tinkering with electronics. My Instructables are all about Arduino.

Intro: Controlling a Character LCD With an Arduino

Hello! Today I will be introducing Character LCDs and showing how to connect them to an Arduino.
It is all very simple and uses only 6 PINS TO INTERFACE WITH!













Note: the image is not mine and comes from http://www.micro-examples.com/public/microex-navig/doc/078-lcdscope.html

Step 1: Parts Needed

You will need the following components to perform this project:
1x '''Arduino (any kind will do)'''
1x '''HD44780 character LCD'''
'''lots of non-stranded wire'''
One 10k Potientiometer

Step 2:

LCDs are pretty usefull things.
They can be used for a project which needs to display something small, to huge machinery.
After all, they are always used for the same purpose.

I will be using a HD44780 Character LCD, with a 16x2 display. (2 lines, 16 characters per line)
They come in all sizes, from 8x2 to 40x4.
they have a 8x5 font and can use up to 8 custom characters.
These LCDs have 16 pins, but only 11 of them are for communication. we will use 6 of them for 4 bit mode.

These LCDs can be run in 4 or 8 bit mode, depending on how many pins you have.

4 bit mode is usefull for saving pins, but only has a refresh rate of 74ms

8 bit mode is usefull for a fast refresh rate (5ms), usefull for displaying custom character animations.

The image shows a few Custom Characters.

Note: the image is not mine and comes from http://www.micro-examples.com/public/microex-navig/doc/078-lcdscope.html

Step 3: Connections

Connect the LCD according to this picture:

Step 4: Test Code 1: Hello World

First, open the file i have added to this step.
Second, copy and paste the file into the Arduino IDE.
Lastly, click the UPLOAD TO I/O board button, or CTRL+U
if everything went to plan, it should now say "Hello World!".

Step 5: Test Code 2: Using 2 Lines

NOTE: For this to work, you will need Arduino - 0017.
open and upload this next program.
it will now say:

Hello
World

Step 6: Test Code 3: Custom Characters

NOTE: to use this feature, you will need Arduino - 0017 or higher.
Now what we will need to do is download LCD CUSTOM CHAR CREATOR.exe  (download below)
Also open the Arduino IDE and copy and paste Arduino_custom_char_example.txt into the IDE.

Open up LCD CUSTOM CHAR CREATOR.exe and type ",0x" into the "Insert before entries" box.
Then click on the pixels to create a character. (I made a smiley)
Then, copy the hex code (highlited in the picture to this part in the IDE:

uint8_t custom_hex1[8] = {0x00,0x0A,0x00,0x11,0x0E,0x00,0x00,0x00};

NOTE: on the program, it has a comma at the beginning, so just highlight the text after the first comma, and press CTRL+C to copy.

Then click UPLOAD TO I/O BOARD     (Or CTRL+U)




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    20 Discussions

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    Sembot

    3 years ago on Introduction

    hai

    Where can I find the Arduino source code for the LCD scope please

    Kind regards

    You can fix that by changing the line "lcd.print(1, BYTE);" to "lcd.write(byte(1));"

    It should do the exact same thing

    0
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    maxrisc

    5 years ago on Step 6

    Or just use http://custom-character.appspot.com/ Google python app to create the characters without having to install Wine on linux to get this to work.

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    robotjam

    8 years ago on Introduction

    Hi, this instructable is exactly what i have been looking for but i am having a problem downloading the custon character creator it keeps wanting to download as a .tmp file amd my computer keeps asking if i want to go online to find a program to open it , which does not work either. I am using a Windows Vista machine. Is this the only character creator that will work with my Arduino? Your help in this matter will be greatly appreciated.

    Thank you

    1 reply
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    Arduino Guy

    8 years ago on Step 3

    you do know that the pot has to be connected to GND - LCD3 - +5volt. yet it will probably work your way.

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    thanh000

    8 years ago on Step 6

    thank, i use AVR and this help me much

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    zenoture

    8 years ago on Introduction

    Hmm, i must be doing something wrong because when I hooked it up and ran the code, all I saw on the first line was squares, nothing else. When i was looking at it from an angle I saw an 'o' and saw a cursor blinking but that's about it... Wired it up exactly like the image, but didn't seem to work. Also, in the Arduino code, it says pin 11 is RW, but on the image, there is no pin 11 connected, and RW on my LCD module is actually pin 5... I tried rewiring it according to the comments in the Arduino code, but then the boxes didn't even come up, so i'm at a loss...

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    thecageybee

    8 years ago on Step 6

    Hi there. Hopefully I can field this one.
    I've just been creating my own symbols for use on a weather station I'm making.
    I've found out that the arduino IDE (0.17 at least, not sure about  0.18) and the LiquidCrystal library that comes with it is only capable of assigning 8 custom characters.
    Hopefully someone knows of a workaround or can supply us with a library.
    Also, the 5x8 matrix is a technical limitation to do with how the LCD is made and controlled, completely different approach than graphical LCDs.
    If you wanted to use a 6x10 matrix you'd have to make each char take up 2 charactors horizontally and 2 vertically. I guess it might be possible, but you'd end up with an 8x1 display.
    Hope I've explained this clearly enough.     The Cageybee

    2 replies
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    Simpson_jrthecageybee

    Reply 8 years ago on Introduction

    A workaround of just 8 characters.

    I just received my first  arduino + 20 x 4 display 6 days ago, so don't shoot me, I'm just a beginner.

    As PC-programmer I normally would define all characters in the setup-part of my program, but I  tried to define different characters in the loop part for my Arduino and... it works !

    Just define all characters you want in several arrays and use those to recreate the characters you want while... you're in the loop. Every time you need a new character you'll have to recreate it. "Old" characters will be replaced by new ones, so... you'll have to recreate the old ones  as well if you want to use those  again. It's probably  easiest  to recreate every non-standard character each time you use it.

    A small example which displays a smiley with and one without a nose using the same self defined character address . I've used the pins for the display (12, 11, 5, 4, 3, 2) as used in the arduino examples and you might need to change the setup part if you've got a different lcd-display.


    #include <LiquidCrystal.h>
    LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

    byte smiley[8] = {
      B00000,
      B10001,
      B00000,
      B00000,
      B10001,
      B01110,
      B00000,
    };
    byte nose[8] = {
      B00000,
      B10001,
      B00000,
      B00100,
      B10001,
      B01110,
      B00000,
    };

    void setup() {
      lcd.begin(20, 4); 
    }

    void loop() {
      lcd.createChar(0, smiley);
      lcd.write(0);
      delay (1000);
      lcd.createChar(0, nose);
      lcd.write(0);
      delay (1000);
    }


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    Simpson_jrSimpson_jr

    Reply 8 years ago on Introduction

    Already noticed some mistakes in my example, sorry...

    I've connected the LCD as described on most pages of http://www.arduino.cc/. which is a little different as described in this article.
    One should replace my

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

    LiquidCrystal lcd(12, 11, 2, 7, 8, 9, 10);    to use the setup of this instructable.

    Next, it's possible to create more as 8 characters using my routine, but I guess there still is a limit. With 5x8 pixels for each character one would need 1600 self defined characters to display all possibilities. ((5*8)^2)
    Arduino will probably not be able to do that.

    How ever, one should be able to create characters like the waveform-characters of this instructable by converting the outcome of analog readings (they look analog to me) to self defined characters, that won't use much memory.
    Besides, most of those 1600 characters won't be very useful anyway.

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    VALKIR

    8 years ago on Step 6

     hey, i really like this, and the char creator will prove invaluable over the next few days for me... i have a question though - the program generates code for a 5x8 or smaller matrix (addresses to be exact) , but what if i want to use it for a different matrix , say 6x10 for example , what would I have to add for aditional "dots" that are "outside" this 5x8 matrix? i'm studying the pattern right now but as far as "outside" goes- i'm kinda stuck.

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    I suggest that you do buy one.  I have two, and I'm very glad that I purchased them. Make sure to find cheap ones though if you don't care about the specific colors/backlights.