How to drive a character LCD displays using DIP switches

 This tutorial will teach you the basics of interfacing with a HD44780 compatible display using some DIP switches and a few other components.

This sort of circuit is a great way to learn how HD44780 displays work.
 

Step 1 What you will need

For this project, you will need

* A Breadboard (http://www.protostack.com/index.php?main_page=product_info&cPath=23&products_id=49)
* A HD44780 compatible LCD display  (http://www.protostack.com/index.php?main_page=product_info&cPath=24_33&products_id=46)
* 9 dip switches (I used an 8 way and a 4 way, but any combination that adds to 9 or greater is OK)
* A micro tactile pushbutton switch (http://www.protostack.com/index.php?main_page=product_info&cPath=22&products_id=23)
* 10 10K Resistors (http://www.protostack.com/index.php?main_page=product_info&cPath=14_31&products_id=37)
* a 100nF capacitor (http://www.protostack.com/index.php?main_page=product_info&cPath=14_28&products_id=19)
* A 1K trimpot
* 16pin header (http://www.protostack.com/index.php?main_page=product_info&cPath=5_9&products_id=32)
* A 5V power source. The protostack 5V power supply kit will do the trick (http://www.protostack.com/index.php?main_page=product_info&cPath=26&products_id=71) but there are many other options too
* Lots of wire (I used cat5)

Comments

[kill_them_now]

i had a trouble on the lcd could you help?
http://www.instructables.com/answers/Help-about-Pogramable-intergrate-circuit/

[Kirbsome!]

Good instructable, but I'm having trouble.
First off, the interface is just 4 bits, so I have to put it in nibble mode.
That shouldn't be a problem, but when I get to "Entry mode" and try to enter 0110, the display turns off. However, I can get it into write mode by pulling all bits low and setting enable high. Then, when I try do write to it, it only displays characters from the bottom line of the reference sheet in step 6.

I've quadruple-checked my wiring several times - what am I doing wrong?

[captalex]

nice one, but i thought you could just hook up an lcd to a pic directly!

[nadav]

 Great instructable! Bit complex but great documentation! Also, a video would be great!

[thewizard42]

I would love to see it in use