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How to test your LCD
YOU MUST ADJUST TRIM POT (its 20 turns)
Using the latest 10-28-2012 Raspbian "wheezy"
First make sure your system is current.
sudo apt-get update
Install Gordons wiringPi
https://projects.drogon.net/raspberry-pi/wiringpi/download-and-install/
then wait wait and wait for it to finish.
now
sudo apt-get install git-core

To obtain WiringPi using GIT:

git clone git://git.drogon.net/wiringPi

Now shut down your system and install LCD.

After powering up for the first time you may need to set the variable resistor. Turn the trim pot (small blue box) with a small screwdriver until you see a single row of square boxes.

cd wiringPi
./build

cd examples
********************************************************
edit lcd.c change the following lines
was
fd2= lcdinit (2, 16, 4, 8, 10, 4, 5, 6, 7, 0,0,0,0);
change to
fd2= lcdinit (2, 16, 4, 11, 10, 0, 1, 2, 3, 0,0,0,0);
save it

make lcd
sudo ./lcd

For python
Was
def __init__(self, pin_rs=25, pin_e=24, pins_db=[23, 17, 21, 22], GPIO = None):
Change to
def __init__(self, pin_rs=7, pin_e=8, pins_db=[17, 18, 21, 22], GPIO = None):
Or if model 2
def __init__(self, pin_rs=7, pin_e=8, pins_db=[17, 18, 27, 22], GPIO = None):

Now you can add the following to enable the four buttons.
How to get at the buttons using wiringPi C functions
//Button 1
pinMode (13, INPUT);
pullUpDnControl (13, PUD_UP);
//Button 2
pinMode (7, INPUT);
pullUpDnControl (7, PUD_UP);
//Button 3
pinMode (12, INPUT);
pullUpDnControl (12, PUD_UP);
//Button 4
pinMode (4, INPUT);
pullUpDnControl (4, PUD_UP);

Then to get the status of button 1
digitalRead (13) //0=pushed 1= not pushed