Serial Enabled 16x2 LCD - How many pins ?

This lcd https://www.sparkfun.com/products/9395 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).

[quote author=Runaway Pancake link=topic=128005.msg962711#msg962711 date=1350651054] Right. It's asynchronous serial:

Communication with SerLCD requires 5V TTL serial at a default baud rate of 9600bps (8-N-1).

[/quote]

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 https://www.sparkfun.com/products/733? in order to control 30 leds.... (6 pins , 3pins/2shift registers)

1+7+2+1+?+1+6 = 18 pins...

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 !