OK, I want to get in on the Matrix Orbital deal where you get the LCD2041 and stuff for cheap. But I'm not a big fan of the green color. I was wondering if it's possible to change the background color (to red or white or something), and how best to do it. It looks like there's a backlight on this model, so is it just a matter of switching the backlight LEDs to the color I want? [EDIT] Whoops, must have missed that on the FAQ... in that case, does anyone know what produces the greenish color in this model of LCD?
It's an LED array which you could replace with EL sheet... I'm not sure if the LCD panel itself is actually green or not though Rob.
It probably has some kind of polarizing film. You could still replace it with a blue EL sheet to get a kind of cyan effect.
Hmmm... I don't think the sheet trick will be likely, since I have no way to get stuff like that. On the other hand, I found a sweet one from... MO's competition, shall we say, that definitely uses an LED array and allows for switching all 70 (!) bulbs. Beauty.
The polarising film is invariably blue and a non-issue unless you're wanting a red display with non-black text and very good contrast. I was referring the colour of the glass LCD panel itself - sometimes it's actually tinted green, so will probably make a blue backlight turquois and may have implications on the contrast. Nearly all MO's displays are LED array backlit. - except the special non green displays and more exspensive EL backlit models IIRC. Rob.
eh... if you are going to change 70 leds... won't it be cheaper to actualy buy one with the right color from the beginning?
Cheese - Ahh, I see. Good point about the screen itself, I'll look into it. If the film will still work for a red/black combo, then that shouldn't be a problem. Smilodon - Heh, ordinarily yes. But what I've been looking for is a red 20x4 LCD (with or without backlight), and the only such one I've found is the parallel model from CrystalFontz. According to MO, red LCDs have issues with contrast, and the bigger the display is the worse it gets. So my plan was to get one of a different color and switch it to red.
...and you'll discover exactly what MO told you, that its contrast is poor!!! The light doesn't get polarised as well at red wavelengths I think... Buy CF's red LCD (you wouldn't sell one if they hadn't partially solved the contrast issues) and then pop an MO controller on the back if you really want an MO display. Rob.
I'm not attached to either company, I was just hoping for a 20x4 display in red. Sounds like it's less practical that I'd thought to do so... I'll just bite the bullet and get the standard one.
Have you considered a VFD with a red filter? You can get quite a range of colors that way. Cheers, Nick R
Sure you know as well as I do that a putting a red filter in front of a VFD generally gives a white-ish output and if you really push it and increase the thickness of the filter you only gain red at the cost of a fair whack of brightness... Rob.
Interesting Rob, didnt realize that! Think I'll buy myself a tin of quality street to get a bunch of colored gels on the cheap (and chocolates!) Nick
LCD modding One other alternative, since you do have some money to spend, would be this: Since the Matrix-Orbital LCD you said is just a mere parallel character LCD with a serial interface board on the back, you could get that, then head on to CrystalFontz and get a 4x20 parallel character LCD of red color, and get your soldering iron, detach the serial board from the M-O LCD and attach it to the C-F LCD. Voila, you have a nice red (or whatever) LCD that's serial as well, and no trouble fiddling with backlights and inverters (for the EL)! How does that strike you?
The red LCD displays do not have as good of visibility as the yellow-green ones. Basically the LCD material (the "glass" -- which is a combination of the front polarizer, the liquid crystal fluid, and the rear polarizer) is pretty much the same in both types of displays. But the yellow-green light is blocked really well by the LCD, and the red light is not blocked so well. The result, for a red-negative display (red letters on a dark background) is that red light "leaks" through the the background, so instead of getting the ideal red-on black, you get red on dark red. Of course you can fiddle around with the contrast setting and backlight level and get something that is quite useable, but it will never approach the readability of the yellow-green backlights. That being said, the "RMC" (red negative) displays are much nicer than the "RGB" (red positive) displays. I actually quite like the "RMC" once the backlight and contrast are tweaked in--the red letters take on a kind of unnatural "sharpness", even though the background is not perfectly black. To my knowledge (except for angering the LCD gods and voiding two warranties in one project) there would not be any trouble dropping a CFAH2004A-RMC-JP like this: into the MO 20x4 unit.
Two? What's the second warranty cast into the void? Of course the MO warranty goes the great voyage, but what's the second? CF parallel LCDs have no warranty whatsoever, unless it's something visible without unpacking it. Oh, and don't worry about the LCD gods... as long as none of the Powerful Liquid Crystals are unharnmed, all the Great Spirits are content...!
