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Topic: 16x2 Lcd screen with UNO, help (Read 1 time) previous topic - next topic

Robban98422

Hi,

I am pretty new to this, i have played around with led mostly, And now i am trying to learn the LCD part.

i have a 16x2 lcd screen with blue background. But i cant get it to work properly, I have used this guide "http://arduino.cc/en/Tutorial/LiquidCrystal"

Can someone meybe tell me very simple how to connect and what code to use? I have the uno.
/Robin

dxw00d

There are example sketches in the IDE. They contain the pins you need to use.

Robban98422

ive noticed that this post is in the wrong category. sorry

i dont know what pin is what on the lcd.

i have 16 pins.

The 3 pin from left is marked with a "1" and the last marked "14"

Ardunio talks about D4,D5 ground, +5, dont know what is what

wilykat

#3
Sep 08, 2012, 02:13 am Last Edit: Sep 08, 2012, 02:20 am by wilykat Reason: 1
Oh those, you need to look for LCD pinout.  Most LCD have 14 or 16 pins. In the LCD tutorial link you posted in your first post, you should have scrolled down to circuit, it shows wiring diagram. However I haven't seen one where the 3rd pin is 1 and last pin is 14, almost sound like the pin numbering is reversed.

Standard LCD (normally found on eBay and other sources) has these pinouts:
1 ground
2 Vsource (usually 5v)
3 contrast for LCD (different function if you used VFD)
4 register select
5 read/write (almost always grounded for arduino use)
6 enable
7-10 are D0 to D3 and can be skipped to save pins on arduino.
11 D4   \
12 D5    all are data pin, it's the instruction LCD gets from host on what to put on display.
13 D6
14 D7   /
15 LED  \
16 LED   These 2 pins can be controlled independently or straight wired to ground and 5v (through current limiting resistor) on LCD pin 1 and 2

I stole this picture long ago:


nearly all character LCD uses this pinout.  Those without backlight do no have the last 2 pins.  If you have a large LCD with 18 pins (4x40), those has extra control line that'd need to be wired in and they have different pinout.

Since your pinout may be different, I'd google for model (check the PCB silkscreen) and see if you can find datasheet or pinout.

Robban98422



That how it looks

i inverted the wires and moved them 2 pins, ( becouse the 1 begins att the second? ) atlast it ended upp with all white squares..

i have a potentometer (im not sure how many ohm it is?) and i am not 100% sure if i connect it right.

ttmchamp

Hi,
My lcd is the same as yours and I am stuck coz all the tutorials have lcd that is different from mine. I don't know how to connect the pins( as I don't know the order of the pins or what each pin stand for!).

This is how the back of the lcd looks like: http://www.icshop.com.tw/images/product_images/original_images/4325_1.jpg

I need help!!!!!!!   :smiley-roll-sweat: 

(I am new to arduino..)

Paul__B

OK, it seems you and the OP here have come across a seriously bent version of LCD.

Nevertheless, to get it to work you need to use the pin numbers as you see them written on your PCB, but the standard functions of each pin number as in this diagram.


I gather yours does in fact, not have a backlight, so that pins 15 and 16 which are next to pin 1 are not connected.  Otherwise they would be pin 16 ground and pin 15, 5V.  So, connect ground to pin 1, Vcc (presumably 5v) to pin 2, a 470 ohm resistor (or a 5k pot) from pin 3 to ground and so on.

ttmchamp

@Paul_B: Thanks!  :D
@Robban98422: I now understood the pin numbering of my lcd..To the right of pin 1 is pin numbers 1 - 14 in order and to the left is pin 15 & 16 respectively.  :)

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