Arduino Forum

Using Arduino => Displays => Topic started by: AsertPL on Apr 06, 2013, 09:38 pm

Title: Help with LCD
Post by: AsertPL on Apr 06, 2013, 09:38 pm
Hi!
I have trouble with this LCD because I cannot read from schematics: http://www.artronic.pl/o_produkcie.php?id=967 (http://www.artronic.pl/o_produkcie.php?id=967). Is anyone here who can explain me how to connect it or can make Fritzing project?
Thanks for support ;)
Title: Re: Help with LCD
Post by: MAS3 on Apr 06, 2013, 10:26 pm
This is a standard display.
You can connect it the same way any 16 pin display is wired.
The extra pins are there because it has a RGB backlight, so you need to have 2 more pins to control backlight color.
Title: Re: Help with LCD
Post by: AsertPL on Apr 06, 2013, 10:57 pm
I'm connecting LCD like this: http://arduino.cc/en/Tutorial/LiquidCrystal (http://arduino.cc/en/Tutorial/LiquidCrystal) and it's not working. My result is screen is orange. I ran the Hello World example with the same way connected pins.
Title: Re: Help with LCD
Post by: arloG on Apr 07, 2013, 12:09 am
I think the vast majority of LCD display problems are caused by wiring mistakes.  I'd recommend you recheck every wire.  The tutorial page you referenced doesn't show the connections to the LED backlight.  If you've followed the tutorial exactly, your backlight shouldn't be lit and it especially shouldn't be orange.  Someone else recently tried an RGB backlight and complained that although they could see "Hello World", it was dim.  Based on that, you probably don't even need to wire up pins 15-18 if you squint.

If you've followed the tutorial, make sure you declare your LCD using:
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

If you're still stuck, take photos clearly showing the wiring from the Arduino to the LCD.
Title: Re: Help with LCD
Post by: JoeO on Apr 07, 2013, 04:27 am
Also post your code.
Title: Re: Help with LCD
Post by: AsertPL on Apr 07, 2013, 05:00 pm
I've looked on the schematic and on Liquid Crystal examples and I founded that GND and 5V are replaced. I changed my pins and it's not working too :c
I've took some photos of my wiring steps:
1. Setup
(http://a.scrapyard.co/60c9nl)
2. Utilities
(http://a.scrapyard.co/4i4cyw)
3. Setting up RGB background
(http://a.scrapyard.co/7fqvza)
4. Connecting GND and 5V
(http://a.scrapyard.co/cf7dih)
5. Connecting Data, Enable and RS to Arduino
(http://a.scrapyard.co/pz1l39)
6. Conencting Contrast to power and Enable and RS to LCD
(http://a.scrapyard.co/d106pc)
7. Connecting Data to LCD
(http://a.scrapyard.co/hbq60l)
8. Result :c
(http://a.scrapyard.co/gbnhd9)

And high res photos links:
1. http://scrapyard.co/xvlifo (http://scrapyard.co/xvlifo)
2. http://scrapyard.co/e8lc6s (http://scrapyard.co/e8lc6s)
3. http://scrapyard.co/x1cxlg (http://scrapyard.co/x1cxlg)
4. http://scrapyard.co/auve8g (http://scrapyard.co/auve8g)
5. http://scrapyard.co/c7j65i (http://scrapyard.co/c7j65i)
6. http://scrapyard.co/rzrgf6 (http://scrapyard.co/rzrgf6)
7. http://scrapyard.co/x0pq8q (http://scrapyard.co/x0pq8q)
8. http://scrapyard.co/t16hgt (http://scrapyard.co/t16hgt)

// JoeO //
My code is Hello World example from Arduino IDE
Title: Re: Help with LCD
Post by: Erdin on Apr 07, 2013, 05:35 pm
Should there be a potentiometer at Vo ? To be able to see something ?
Title: Re: Help with LCD
Post by: AsertPL on Apr 07, 2013, 05:38 pm
Maybe, I thought Power can be replacement for Potentiometer.
Title: Re: Help with LCD
Post by: Docedison on Apr 07, 2013, 05:50 pm
No Not at all But a 4K7 resistor from +5V to the contrast pin and a 330R resistor from the contrast pin to ground should work a charm.

Bob
Title: Re: Help with LCD
Post by: arloG on Apr 07, 2013, 07:04 pm
Start with LCD pin 1.  To me it looks like it's connected to a red wire that goes to the positive trace on your breadboard (pic 4) and from there to the +5 pin of your Arduino.  The tutorial you cited shows this pin as grounded.

For LCD pin 2, it looks like you've got this pin tied to ground through a resistor (also pic 4).  The tutorial shows this pin to be the 5 volt supply.

Pic 4 is entitled "Connecting GND and 5V".  I don't see a wire to ground.  Only the resistor.

Check the connections to the first 3 pins on the LCD.

I had trouble mentally detangling some of your wires.  Using the same color for all 4 data lines discouraged me from spending more time on it until you checked the power connections.
Title: Re: Help with LCD
Post by: AsertPL on Apr 07, 2013, 08:21 pm
// Docedison //
On Thursday I'm going to electronic shop, so I can buy potentiometer, thanks for help ;)

// arloG //
Look at the schematic for my display: http://www.artronic.pl/o_produkcie.php?id=967 (http://www.artronic.pl/o_produkcie.php?id=967)
First is 5V, second is GND.
Title: Re: Help with LCD
Post by: floresta on Apr 07, 2013, 08:34 pm
Quote
Maybe, I thought Power can be replacement for Potentiometer.

You can never get a display by using 'Power' (meaning 5V) on pin 3 but you sometimes can get a usable display by using GND.  You could try this until you get your potentiometer.

That may get your display to power up but it looks like you have nothing connected to pin 5 (R/W) of the LCD module.  You will not get the LCD controller to initialize correctly or to display any characters until you connect that pin to GND.

Don
Title: Re: Help with LCD
Post by: AsertPL on Apr 07, 2013, 08:52 pm
// floresta //
I think so, because when I connecting Contrast pin with resistor etc. I have something like black pixels :s
Title: Re: Help with LCD
Post by: arloG on Apr 07, 2013, 09:23 pm
Well, I'm obviously missing something.  I looked at your schematic.  It says pin 1 is Vss and pin 2 is Vdd. 

Don correctly notes that you've got to fix R/W.