lcd code and how to connect.

I bought a 2x20 4bit lcd and a 4x20 4bit lcd. Both can also do 8bit. They both work with the HD44780 chip.

I want to use no more digital pins as absolutly needed. I had the idea 4bit work with only 4 data pins, but when i see a connection drawing... http://www.km5z.us/files/arduino-fm/4-bit-LCD_schematic.jpg Here I also see DI and enable. I understand you always need 6 pins on the arduino plus 5v power.

I'am new to Arduino, and never programmed a lcd. I see so many different codes, and a ton of librairies. Whats the best and easiest way to start working with my 4x20lcd? What librairies should I use? What are the differences, where can I see the most sample codes from? Whats smart to do here?

I understand you always need 6 pins on the arduino plus 5v power.

That is correct for the first LCD. You can implement additional LCDs with one additional pin for each additional LCD module. You can purchase a serial interface, which is actually a dedicated microcontroller, that will get you down to one digital pin per LCD module.

What librairies should I use?

That's easy - use the LiquidCrystal library that comes with Arduino v0018.

Start with the tutorial at http://arduino.cc/en/Tutorial/LiquidCrystal. If you have any trouble getting it to work then check out the more extensive tutorial at http://www.ladyada.net/learn/lcd/charlcd.html.

Don

Thanks for this helpfull information!

One more pin for one more lcd, I didn't know that, interresting. I think I do not need that at the moment, I have a 4 line lcd. Maybe it's smart for me to use 2x 2line lcd's because of the design I make. But I try 1 4line first.

One more pin for one more lcd…

Look here: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1265969050/0

Don

For about $15, you can buy a little unit to save you (minor) hassle, and save your Arduino many of the chores of driving the panel. With this, the pins to control the LCD are reduced to an absolute minimum.

Full details at....

http://sheepdogguides.com/arduino/art8lcd117.htm

For about $15, you can buy a little unit to save you (minor) hassle, and save your Arduino many of the chores of driving the panel. With this, the pins to control the LCD are reduced to an absolute minimum.

Full details at....

http://sheepdogguides.com/arduino/art8lcd117.htm

Isn't this just a convoluted way of saying:

You can purchase a serial interface, which is actually a dedicated microcontroller, that will get you down to one digital pin per LCD module.

(from reply #1)

Don