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Hello everyone smiley

I have this LCD - lmb162abc

here is the data sheet

http://www.topwaydisplay.com/Pub/Manual/LMB162ABC-Manual-Rev0.2.pdf

on page three of the data sheet it seems to indicate there are two options for the background color, green and deep blue.
I have been searching the internet for a while now to try and find out how this works, and how to write the code to make it happen, but everything I can find is for RGB LCD's mostly from adafruit.
Am I reading the datasheet wrong, or are there actually two colors available.  It is very possible I have misunderstood what I read and there is only one color available, and it would be model dependent on which color you have.

I am using the LiquidCrystal library to control the LCD, and if it actually does change color, I would very much enjoy being able to do so.  If anyone could show me how to do this, or let me know if I am wrong on my understanding, that would be great!

Thanks in advance for any help provided
N8

edit to correct myself, wrote my post as backlight color, but it's actually the background color

« Last Edit: January 17, 2013, 07:16:44 pm by Neight » Logged

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Think the colour changes if you switch Back light on or off. (thats how I interpret it)

According to the PDF you posted there are LEDS for backlight. You could connect this to a PWM pin of the Arduino and adjust the back light...
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going to play with some code for this to try it, but at the moment I have the LED back light wired through a toggle switch, to be able to manually turn it on and off, and when the switch is off, all it does is turn the LED off, it doesn't change colors when the back light is off.
The way I read it, there should be some line of code I could write to change the "Display Data" to either 1 or 0 and thus change the color.

it also says that yellow-green is the inactive background color, which would also indicate you have to do something to change the active background color.  though looking at the background on this display, it really doesn't look like it would change color.

The whole wording of it is a bit confusing if you ask me.

I will try and write some code to turn on and off the LED back light and see if that makes a difference over a physical switch, but I don't understand why that would matter.  maybe using PWM to fade it down to off might make a difference?

eh, I honestly have no idea, but thank you for your input, I greatly appreciate it!
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Ok, I have played with this a bit, and gotten nothing new to work from.
tried using some code to turn on and off the LED back light, and also used a PWM pin to fade it on and off, and no color change.  all that happens is the LED turns on and off, or fades on and off, which is what I expected, but what the hell, worth a shot, right?

not sure what to make of it, and I don't have enough experience with LCD displays or Arduino in general to know where else to begin trying.

one good thing I got out of this process so far, I am going to use a timer to turn the back light off after some period of inactivity.  save me some battery power.  This is a digital dice project for gaming, and this thing could be sitting on a table left on for quite some time, but only used intermittently, so this makes a nice addition to my code to save the battery and not have to turn the unit on and off for each use smiley
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Saw no mention of the display data command in the documentation.
Maybe the same lcd is available elsewhere with another datasheet?
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Saw no mention of the display data command in the documentation.
Maybe the same lcd is available elsewhere with another datasheet?


I didn't see it again after it was mentioned on page 3.  I have scoured the data sheet, and even read all three revisions of the manual that have been released.  minor changes made in each revision, but no mention of background color after page 3 in any of them.

I have dismissed this idea twice in the last week, but something keeps drawing me back to it.  It would be a fun addition to my dice roller if the screen could change colors based on mode, or when the dice are "rolling".  it would just be for fun, and the unit works just fine without the addition of a color changing screen, but I do like the idea.  If it wont work, it is really no big deal, I am mostly just following my curiosity at this point.
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Page 3 tells you about 2 colors.
You have the option to have Deep blue by switching on the pixel, or the alternative of Yellow green by turning it off.
It is a monochrome display.

Just take a peek at the remarks to those lines where it says "The Color is defined as the inactive/background color"
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Page 3 tells you about 2 colors.
You have the option to have Deep blue by switching on the pixel, or the alternative of Yellow green by turning it off.
It is a monochrome display.

Just take a peek at the remarks to those lines where it says "The Color is defined as the inactive/background color"

ok, so if I understand this correctly, the color deep blue is just a descriptor for when a pixel on the display is on.  otherwise the pixel is the default background color.

the pixels that are on do not look any shade of blue to me, but I guess that is neither here nor there how I would describe it.

That does make sense, even if I don't agree with them on what they are calling deep blue smiley-razz

Thank you for clearing this up for me.  I was about to ask if this might be a feature of 8 bit mode, because I can't seem to find an application where 8 bit mode would even be used.  It was making me wonder if 8 bit was for two color mode. 
This thing sure looks monochrome to me, and it was a bit confusing that they were describing it otherwise.

Very much appreciate both of you taking the time to help me investigate this!
Thank you
N8
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Quote
I was about to ask if this might be a feature of 8 bit mode, because I can't seem to find an application where 8 bit mode would even be used.
The 8-bit mode is really just a carryover from the olden days when the LCD was hooked onto the data bus of an 8-bit microprocessor and treated just like any other memory mapped device.  It does not provide any added features and there is little reason to consider it except when you are starting out to learn how to control one of these displays on your own, without using a library written by others.

Don

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The 8-bit mode is really just a carryover from the olden days when the LCD was hooked onto the data bus of an 8-bit microprocessor and treated just like any other memory mapped device.  It does not provide any added features and there is little reason to consider it except when you are starting out to learn how to control one of these displays on your own, without using a library written by others.

Don



Thanks for the information Don smiley

That does explain the last of my questions when dealing with this LCD screen.
I really should sit down and learn the steps that are covered in the LiquidCrystal library so I know what is going on behind the scenes of the sketch, but for the moment, I am happy to have the library to use and be able to get my current project working with little trouble.
This particular project has been a bit of frustration, and having it working right so far is a relief.
Thank you for filling in some gaps for me, I very much appreciate it!
N8
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