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1  Using Arduino / Displays / Re: 16x2 lcd with UnoR3 probs on: December 22, 2012, 05:38:36 pm
Finally! Thanks for all help! Really appreciate it:D
2  Using Arduino / Displays / Re: 16x2 lcd with UnoR3 probs on: December 22, 2012, 10:14:56 am
And here is the code :

#include <LiquidCrystal.h>

LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

void setup() {
  lcd.begin(16, 2);
  lcd.print("Hello arduino.cc!");
}

void loop() {
  lcd.setCursor(0, 1);
  lcd.print(millis()/1000);
3  Using Arduino / Displays / Re: 16x2 lcd with UnoR3 probs on: December 22, 2012, 10:12:36 am
Ok. Now I've got a brand new display. Ive solder a header on it, then made the right connections. Anyway the LCD's backlight wont light up.
And yes I have tried from the beginning with resistors. I've started on 680 ohm resistor and then went down to a 560,470,390,330,270,180,150 and now a 100 ohm, still this stupid backlight wont show up.
Here's a pic with little more Christmasfeeling..


Now when I thougt of it.. When I had my old display and the wrong connections the backlight went up at least.
Like here: https://vimeo.com/54704282
Something is very mysterious with this special lcd.
Seems like the LCD from usa on ebay is much more easy than this model.
http://www.ebay.com/itm/1pcs-1602-16x2-HD44780-Character-LCD-Display-Module-LCM-blue-blacklight-New-/281040213404?pt=LH_DefaultDomain_0&hash=item416f4d559c

4  Using Arduino / Displays / Re: 16x2 lcd with UnoR3 probs on: December 07, 2012, 03:38:49 pm
Ok, I got the contrast working now, I can se the bars.. But to get the volts down to 4,2 on my pin 15, I needed a 560K resistor... And when I got that volt it didnt light up.
So I think my backlight must have been broken.
5  Using Arduino / Displays / Re: 16x2 lcd with UnoR3 probs on: December 04, 2012, 03:50:15 pm
I found a similiar LCD (if its not the same) , with exactly the same boarddesign, and numbers of the pins : http://www.produktinfo.conrad.com/datenblaetter/175000-199999/181664-da-01-en-LCD_MODUL_STN_POSITIV_LED_WEISS_16X2.pdf

Anyway, when I wired only the VSS and the VDD from the LCD to my arduino (just making sure the LCD worked) it didnt come alive, not a sign, so, I suppose it must be broken.
6  Using Arduino / Displays / Re: 16x2 lcd with UnoR3 probs on: December 04, 2012, 06:26:35 am
Ok, I think this is kind of embarrassing..

I havent noticed the pinmarks on the backside of the lcd, because the gudie I followed was for just the same lcd.

But here is a pic of the backside of my lcd : http://oi46.tinypic.com/30tqeio.jpg

Is it true that the first pin to the left is my number 15 and next is 16?
Because I thougt the very first pin to the left was my pin number 1.
7  Using Arduino / Displays / Re: 16x2 lcd with UnoR3 probs on: December 02, 2012, 12:07:57 pm
Quote
I've recently tested to connect the backlight to the 3v pin on the arduino instead.
Regardless of how you power an LED you still need some way to limit the current and this almost always involves the use of a resistor. 

Depending upon the LED configuration in the backlight circuit the 3 V supply may not provide enough voltage and/or current to work properly.

You should power the backlight from a 5 Volt supply using a resistor in between the supply and one of the backlight pins.  Unfortunately your data sheet does not supply enough information to determine the required resistance so you will have to experiment.  I would start out with about 150 ohms and see if the voltage across the LED is then within specifications and if the backlight is sufficiently bright.


Quote
Could I have destoyed the backlight when I wired it to the +5V?
You didn't help it or the Arduino power supply at all, but you probably didn't destroy either of them (yet) either.
 
Don

Thanks for the help so far!!
Will buy everything tomorrow, and come back with the result.
8  Using Arduino / Displays / Re: 16x2 lcd with UnoR3 probs on: December 02, 2012, 11:49:15 am
Quote
Here is a clearly pic of how I wired everything...

Look in the lower left box in the 'Description of Terminals' and you will see that the backlight must be supplied with no more than 4.5 Volts.

This means that you must use a series resistor to drop the voltage and at the same time limit the current through tbe LED backlight.


Don

I've recently tested to connect the backlight to the 3v pin on the arduino instead. But its the same. (Ive solder the wires on the backside of the LCD)
Could I have destoyed the backlight when I wired it to the +5V?

Will buy the headers tomorrow and solder it.
9  Using Arduino / Displays / Re: 16x2 lcd with UnoR3 probs on: December 02, 2012, 08:18:23 am
When I checked the potentiometer,I used a voltmeter and looked at the output voltage when the arduino was running and only coupled in the voltage from the arduino.I think the potentiometer works because it gives diffrent voltage to the LCD. It also changes the contrast a liiiiiitle liiiitle bit.
Little bit hard to see it in the video tho.
Here is the video: https://vimeo.com/54703995

Here is a clearly pic of how I wired everything, and a pic I got from the manual to compare with.
http://tinypic.com/view.php?pic=2ldubtt&s=6

Here is a video showing how the white boxes flashes when I turned the potentiometer with everything wired:
https://vimeo.com/54704282

Here is the manual for the LCD from the manufactor:
http://www.kjell.com/.mvc/Document/File?id=b6e33422-63ff-48be-b140-a04a0114d7ef

And here is the code I was runnning with everyting coupled in the pic:

#include <LiquidCrystal.h>

LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

void setup() {
  lcd.begin(16, 2);
  lcd.print("hello, world!");
}

void loop() {
  lcd.setCursor(0, 1);
  lcd.print(millis()/1000);
}


10  Using Arduino / Displays / 16x2 lcd with UnoR3 probs on: December 01, 2012, 03:44:16 pm
Hi!

It seems I got the famous problem with the lcd. The letters wont appear.
Its a 16x2 blue lcd.

Have checked the cables over and over again and I find it correct.
The LCD starts and the backlight shows, but not the letters.
Sometimes the white boxes flashes a millisec or so, then disappears.

Im followed the Hello world guide wich comes with the arduino.
I got the 10K potentiometer. And I have tried with and without it, same result.
I also cant change the contrast with the potentiometer coupled on. Ive
checked the outputvoltage on it,and it works!
Anybody that got an idea? Can link a video if someone want a look.
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