This lcd Serial Enabled 16x2 LCD - White on Black 5V - LCD-09395 - SparkFun Electronics needs only 1 digital pin to be connected to arduino ? Thanks
Right.
It's asynchronous serial:
Communication with SerLCD requires 5V TTL serial at a default baud rate of 9600bps (8-N-1).
What do you mean "asynchronous serial" ? im very new sorry...
I want it to display text like this "hello my name is 123"
invader7:
This lcd https://www.sparkfun.com/products/9395 needs only 1 digital pin to be connected to arduino ? Thanks
Yes that is correct. If you take a look at the "SerLCD v2.5 Datasheet" (found at your link) it says: "Only three wires -5V, GND, and Signal - are needed to interface to the LCD."
What do you mean "asynchronous serial" ? im very new sorry...
That's a fancy way of saying that the data does not have to be supplied at a fixed rate. For example, If you sending data from a keyboard you can pause between keystrokes and not mess up the communications.
Don
Thanks big win , in the fight to free up UNO pins .... i have a lot of stuff to connect... 
i have a lot of stuff to connect
Like what? just curious ...
Have you checked the I2C bus, it can connect up to ~120 devices ...
robtillaart:
i have a lot of stuff to connect
Like what? just curious ...
Have you checked the I2C bus, it can connect up to ~120 devices ...
http://arduino.cc/forum/index.php/topic,127924.0.html
i will need :
LCD (1 pin)
Keypad (7 pins)
2x Sensors (2 pins)
2x fan (1 pin only on/off)
Gsm shield - https://www.sparkfun.com/products/9607 i dont know how much pins....
1 servo ?? (i dont know if it is that i want...) i will open 1-2 very light cardboard-like windows.... (i guess 1 pin)
4 Shift Register 8-Bit - SN74HC595 - COM-13699 - SparkFun Electronics? in order to control 30 leds.... (6 pins , 3pins/2shift registers)
1+7+2+1+?+1+6 = 18 pins...
- http://www.instructables.com/id/Analog-Keypad-Backpack/#step1 - reduces from 7 => 2
robtillaart:
- http://www.instructables.com/id/Analog-Keypad-Backpack/#step1 - reduces from 7 => 2
GREAT ! i think to 1 , because it has 3 pins , +5 GND and yellow to A0
GREAT ! i think to 1
That shows you understood the story 
(I first had a link to an I2C keyboard which needed 2, but then found the analog one and forgot to change the text)
robtillaart:
GREAT ! i think to 1
That shows you understood the story
Thank you very much , i have one more question about the lcd, its serial so it needs TX and RX , 0 and 1 pins of my arduino... I want to connect a gsm shield , which needs TX and RX pins too...
As i found out , pins 0 and 1 are the hardware serial ... If i want to connect another serial device i will have to see http://www.arduino.cc/en/Reference/SoftwareSerial in order to make , lets say pins 2 and 3 , software serial and then i will have 2 serial working devices .. is that right ? thanks !
Yep,
Note that for the serial LCD you only need a TX line.
Use the HW serial for the GSM, and use software serial for the LCD and define pin -1 as the RX pin (yes minus one) of the SWSerial. This way you do not loose a pin.
(disclaimer: This trick works with the newsoftserial on which the 1.0 SWserial is based)
robtillaart:
Yep,
Note that for the serial LCD you only need a TX line.
Use the HW serial for the GSM, and use software serial for the LCD and define pin -1 as the RX pin (yes minus one) of the SWSerial. This way you do not loose a pin.(disclaimer: This trick works with the newsoftserial on which the 1.0 SWserial is based)
Great when i have the equipment i will give it a try !