Max character LCD lines

After doing some searching for an LCD (HD44780) with more than 4 lines, I found several variants. I saw a 40x4 but I need more lines, not more characters per line. And I know that the 20x4 LCDs that I have can be made to display 6 lines, but the font size was a bit small.

So I searched for an LCD with > 4 lines but couldn't find one. So I think that's the answer, or so it would seem: they aren't available. Just wanted to confirm on the forum before I move ahead with settling on an enclosure: is that correct? 4's the limit, at least for now?

Thanks

It is not any practical limit but you seldom need more. If you want more you could consider a graphics LCD.

av8or1: 4's the limit, at least for now?

No. It may be the practical limit for LCDs of that genre, but there is as swag of LCDs out there. I have retired the 4x20s for Nokia 5110s, which have six lines. They only have 12 characters but the lines have more value for me. The cursor is dot-addressable and you can easily do custom glyph. This means you might get an extra character in a line.

Ok thank you for the replies. No need for graphics in my application, so I'll just stick with what I have. But maybe I can find them cheaper on EBay, we'll see...

Ah… I forgot to mention that, not only do the 5110s have 6x12, but they are also a lot cheaper than the 4x20s. I got them for the lines, the price is character size.

Another option is a Nokia 1100 LCD. It's also very cheap and can display 16x8 characters.

Nick/Coolest,

Thank you for the feedback. I'd agree that those displays are better and cheaper, but I also agree that the tradeoff is character size. In my application, the larger font is a better choice. So I'll just stick with the 20x4s but haven't had time to go searching for the best deal on them yet...

Thanks again

Not sure how to display 6 lines instead of 4 but this is a BIG display from eBay…
worked for me…

http://www.ebay.com/itm/320480796436?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

right,I’ll just stick with what I have. But maybe I can find them cheaper on EBay and amazon

Off the top of my head, there is 1608 & 2008. There hard to find, there essentially 2 controllers , the 6 line display undoubtedly has 2 controllers if its a HD44780. The HD44780 can be daisied upto 4, giving 16 lines, but nobody makes them as there is no demand. The library for the HD44780 can do up to 8 lines as it sees both chips as one. So 6 lines is very doable.

If anyone ever finds some 1608, 2008 or 4008's i would like to know!

This is definitely 2x HD44780 http://www.ebay.com.au/itm/Character-LCD-Module-Display-2004-204-HD44780-Blue-Blacklight-/190668230303?pt=AU_B_I_Electrical_Test_Equipment&hash=item2c64b64e9f

CarlW: Not sure how to display 6 lines instead of 4 but this is a BIG display from eBay... worked for me...

CarlW-

What is the LCD on the left? It looks like the standard-sized (if you will) 20x4, probably with the same dimensions that my units have I would guess. The display you found on the right is indeed way-huge, but would be disproportionate in my application I think. Hah! Can you imagine putting that thing in a hand-held enclosure?!?!! Good times...

What I'm doing will serve the purpose for now. I intend to play around with the 6 line mode of my LCDs just to lay eyes on exactly how big the characters are, but I suspect that they'll be just a bit small, as the current size seems proportionally correct to the enclosure size that I have in mind.

I have saved a link to your post though, for reference in future projects! :-)

JB_AU:
Off the top of my head, there is 1608 & 2008. There hard to find, there essentially 2 controllers , the 6 line display undoubtedly has 2 controllers if its
a HD44780.
The HD44780 can be daisied upto 4, giving 16 lines, but nobody makes them as there is no demand. The library for the HD44780 can do up to 8 lines as it sees both chips as one. So 6 lines is very doable.

If anyone ever finds some 1608, 2008 or 4008’s i would like to know!

Good information, thanks!

The library for the HD44780 can do up to 8 lines as it sees both chips as one. So 6 lines is very doable.

Please explain this a little more fully.

Don

I have a technical paper from Stanford University from 2000(something) that uses a 8051 to interface with a ??08, it stated that there where 2x HD44???. The header was a close match , almost verbatim copy. It was a brief for interfacing some expensive science equipment. So i started looking for 1603, 1604, 1605 etc, I found a 2004 & reference to a 1608 , & a cached thread talking of a 40 character 8 line display. There is 4 documents i should have (somewhere). I could not recollect the exact procedure, but another thread talked about using the same lcd library for the 1608 as is used for the 2004 & 1602, and this was for some type of arduino.

I stress that i am unsure what the 4 documents i have are called, or where they are or came from or their exact contents, but i do recollect some of the contents, & when i find them, i will share.

I don't see a limit on the number of HD47780 chips you can have in a display, in theory, since all you need is an extra Enable line for each controller. What the 40x4 displays do is have En1 and En2 pins. That way you select which controller you're accessing. The HD47780's RAM is structured as 2 lines 40 chars long. I could never understand why the 2004 displays are setup the way that they are with line 0 and 2 are line 0 in ram and line 1 and 3 are line 1 in ram instead of just being consecutive, line 0 is 0 and 1 on the lcd and line 1 is 2 and 3.

How about using 2 20x4 displays connected to an I2C backpack? Only $10 on ebay. http://www.ebay.com/itm/310575296583

As it is no fun searching thru terabites of information, i did find a page i saved from John Boxall's site that uses a 40x4 lcd & a different library, i'm still looking though; http://tronixstuff.wordpress.com/2012/06/11/kit-review-akafugu-twilcd-display-controller-backpacks/

40x4 44780 compatible display http://www.buy-display.com/default/40x4-lcd-arduino.html

I pointed out the I2C backpacks, because you can use 4 lines on the arduino to power up to 8 displays using the PCF8574 I2C port expander. Another option that is going to be much faster is to use a register shifter such as a 595 on the SPI bus, but this requires 3 lines + 1 line per each additional display.

I don't see a limit on the number of HD47780 chips you can have in a display, in theory, since all you need is an extra Enable line for each controller. What the 40x4 displays do is have En1 and En2 pins. That way you select which controller you're accessing.

This information is correct. See this post for a demonstration --> http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1265969050

The HD47780's RAM is structured as 2 lines 40 chars long. I could never understand why the 2004 displays are setup the way that they are with line 0 and 2 are line 0 in ram and line 1 and 3 are line 1 in ram instead of just being consecutive, line 0 is 0 and 1 on the lcd and line 1 is 2 and 3.

Follow the [u]LCD Addressing[/u] link at http://web.alfredstate.edu/weimandn for an explanation of what is going on here.

Don

@JB_AU
I don’t see how any of this explains your statement “The library for the HD44780 can do up to 8 lines as it sees both chips as one. So 6 lines is very doable.”

I am fully aware of the 40x4 displays and the library that was written for them → http://code.google.com/p/liquidcrystal440/.
Neither this library nor the standard LiquidCrystal library can deal with 8 lines unless you run multiple instances as demonstrated in the link in my earlier reply.

Don