3 Digit LCD and Driver IC

[ClayE]

OK, I have been beating my head long enough on this and am wondering if someone would be so kind as to give me some assistance or point me toward some helpful reading.
I am wanting to use a small display (1" x .5" or smaller) to display 3 digits without any decimal point. I have found a 3 digit LCD by Lumex (http://search.digikey.com/scripts/Dk...ame=67-1799-ND) and a driver IC by Maxim (http://datasheets.maxim-ic.com/en/ds...11-ICM7212.pdf). It appears that it might be a potential solution, but I am having troubles understanding how to make them work and I can't find anything in the forum or the manual on this. It may be there and I'm just not smart enough to recognize it.

I am using picBasicPro 2.47, and lab x-1 board, and a pic 16f877a. I have migrated to the picproto64 for this design.

My constraints are the size of the display and the number of digits. how to get there is all optional at this point (except that i am already using 15 of the io pins).

So, anyone have any advise or experience using small displays?

thanks.

P.S. I know this is somewhat vague, but I'm trying to figure out how to try to make the display work before I buy the parts.

[Darrel Taylor]

You pointed to the ICM7212, but I think you'll need the ICM7211M device for an LCD.

It seems pretty straight forward, put the BCD digit on the data inputs, 2 pins select the digit, then stobe the CS line. Takes 7 pins on the PIC.

[manwolf]

Or what about a MicroChip AY0438 32-Segment CMOS LCD Driver needs only 3 pins as it is serial.

http://ww1.microchip.com/downloads/e...Doc/80438a.pdf

Price is not to bad either about 1.53USD

[ClayE]

Thanks for the information Darrel and manwolf. I have decided I need to start with making a few LCD displays work and then look at something like this. I have found a source for displays that has reasonable prices and good documentation. So I ordered 3 different displays to get some experience with. I decided that the fact that I even asked the question shows and need to get some more display experinece.

If I don't break stuff down into real small steps I usually run into problems.

I ordered a 1x8, 2x8, and a 120x32. Should be here Wednesday. I'll update on how it goes.

Thanks again for the help.

[skimask]

I ordered a 1x8, 2x8, and a 120x32. Should be here Wednesday. I'll update on how it goes.

A couple of notes for you...
1x8, 2x8, most likely common LCD types, parallel input, should be able to be driven by PBP directly using LCDOUT...
120x32 (you sure that's not 122x32?), not going to be able to be used by PBP directly (i.e. LCDOUT), but there are a few threads around here, one by me, with code that works to drive this particular GLCD (just do a search on 122x32).

[ClayE]

Thanks skimask. the 1x8 uses a KS0066U controller, and the 2x8 uses a SPLC780D. The supplier said both were "equivalent to the 44780". I picked them to get some experince with the two different controllers. I figured it was a good way to learn.

I picked the 120x32 (I checked, and they publish this as the size, maybe it is a type) because it had a data sheet that at least looked like something I might be able to grasp (at least enough to get started! ha).

thanks for the tip on the thread, I will be checking it out.

FYI, here is the link to the 120x32
http://www.newhavendisplay.com/index...rod/prd266.htm

Thanks for the help

[ClayE]

skimask,
Thanks for the great thread on the 122x32. it is a huge help.

[skimask]

Thanks skimask. the 1x8 uses a KS0066U controller, and the 2x8 uses a SPLC780D. The supplier said both were "equivalent to the 44780". I picked them to get some experince with the two different controllers. I figured it was a good way to learn.

Sure, 2 different controllers that are both 'equiv to the 44780'. In other words, they'll mount the same, most likely initialize the same, and except for the different in the number of lines, operate the same.

I picked the 120x32 (I checked, and they publish this as the size, maybe it is a type) because it had a data sheet that at least looked like something I might be able to grasp (at least enough to get started! ha).

I just had a look at that datasheet. The company may have screwed up the datasheet all the way thru, or it really is a 120x32 LCD. If it is actually a 122x32, you'll notice 2 blank vertical lines in the middle of the LCD once you get it up and running, then you'll know it's a 122x32.
But it does use the SED1520 controller, the same thing as 'my' 122x32 GLCD, so the code should transplant right over.

[ClayE]

well I got my LCD modules in and after lots of studying, figured out how to hook it up. couldn't get anything on the display, then ended up getting junk. after couple of code changes, and finally changing the LCD_DATAUS to 50 from 20, I'm getting what I expect on the display. I'm still getting the first line all "black squares" (or what ever you call it when all the dots are on) on power up. They clear with the clear command, but seems like it shouldn't be doing the "light up the first line" thing when powered up. I'll keep grinding to figure it out. (the second line of the display does not do this).

[skimask]

I've got more than a few styles of parallel LCDs in the shop.
The bulk of them power up to a cleared screen. A couple of them power up the way you describe, one of them powers up with random garbage all over the screen every time. It's probably got to do with how messy the power supply is or it's rise rate or...well, I don't care. As long as they 'clear' after they 'boot', I'm happy.

Are you able to display what you want to or does it come out garbage?

[Archangel]

well I got my LCD modules in and after lots of studying, figured out how to hook it up. couldn't get anything on the display, then ended up getting junk. after couple of code changes, and finally changing the LCD_DATAUS to 50 from 20, I'm getting what I expect on the display. I'm still getting the first line all "black squares" (or what ever you call it when all the dots are on) on power up. They clear with the clear command, but seems like it shouldn't be doing the "light up the first line" thing when powered up. I'll keep grinding to figure it out. (the second line of the display does not do this).

Hello ClayE, could we peek at the code up through the first lcdout routines? You might try . . .LCDOUT 254,1, "MyString"
That should clear the LCD and print MyString on line 1