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Author Topic: Why is my LCD not working? no contrast?  (Read 765 times)
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Hi!
I bought this LCD: http://www.engineersgarage.com/electronic-components/16x2-lcd-module-datasheet
and am trying to get it to work with my arduino.

I have followed the instructions found in this video:

and am trying to run this program (a progress bar): http://jeremyblum.com/wp-content/uploads/2011/07/Episode-13-Arduino-Programs.zip

although I am not getting anything from the LCD when I turn it on or try to run the program.

I think the problem might be with the contrast, are you supposed to see something on the screen when you start it up even if your not programming the LCD?
I hooked up a 5k pot on the VEE, ground, and +ve but still am not seeing anything.

Here is a picture of my whole setup: http://imgur.com/KpwPz,XD2Ij#1
and here is a picture of the back of the LCD: http://imgur.com/KpwPz,XD2Ij#0

thanks for any help! smiley
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How do you get data to your lcd?
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How do you get data to your lcd?


what do you mean? Isnt the data being sent through d4-7?

I found that I am having the same problem as this person in this post: http://arduino.cc/forum/index.php/topic,18381.0.html

however there is no answer in that post...
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Quote
Isnt the data being sent through d4-7?

Is it?
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How do you get data to your lcd?
I think he meant 'How do you get power to your LCD'.  

Edit: No - he didn't.  His original comment stands.

Don
« Last Edit: January 11, 2013, 08:38:15 pm by floresta » Logged

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After you put power on pins 1 and 2 you should be able to display a row of blocks.

Even after you put power on pins 1 and 2 you will have to ground pin 5 before you can display any data.


Edit:  You will also have to deal with the data.  On the other hand, everything is nice and neat.

Don
« Last Edit: January 11, 2013, 08:39:27 pm by floresta » Logged

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Here is a picture of my whole setup: http://imgur.com/KpwPz,XD2Ij#1

Check your wiring.

The picture shows two jumpers across the trench in your breadboard for some connections, direct wiring for others, but it looks like your gold data lines are disconnected.  Put jumpers over trench for them and it will probably work.


* jumo.jpg (46.61 KB, 464x360 - viewed 15 times.)
« Last Edit: January 11, 2013, 08:53:14 pm by Nick_Pyner » Logged

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Put jumpers over trench for them and it will probably work.

Not likely without power and with R/W floating.

Don
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PlasmaNinja,
You have many wiring errors.
Have a look at the video again, particularly around the 5 minute mark.
The one thing not shown in the video is that pin 16 is on the left and pin 1 is on the right
of that drawing.

Wire up all the connections to the 16 pins on the header as shown in the video.

One thing that you may not know/understand is that power connections for the backlight
and the LCD are totally separate.

The backlight power lines appear to be soldered directly to the backlight connections
rather than to the A (LCD pin 15) and K pin (lcd pin 16)  on the 16 pin header.
A potential side effect of this is that it may bypass the current limiting resistor.
If so, this will eventually damage the backlight.

There is also a strange wire connecting connecting D3 to K
(LCD pin 10 to LCD pin 16)
 I am assuming that was supposed to be the R/W pin on the LCD.
If so it is using the wrong LCD pins.

--- bill
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