Big Characters

att_jay

Hello
As jus new to be working with LCD displays like
http://www.sparkfun.com/products/256
Please give me an idea how to enable the big numeric digits e.g. 0, 1 ...9 that uses 4 lines and fills the entire display with 4 numeric digits.
I am lookingfor some Spin object that can do so for me. I have checked that display ROM does have some built in character library but that works only for standard digit only not for big digits which I am looking for.
Any help in this regard would be highly appreciated.

Cheers
Jay

erco

Save your Prop for something better. Here's a $5 1-chip solution: http://www.phanderson.com/lcd106/lcd107.html

Phil Pilgrim (PhiPi)

Jay,

Displays like that, based on the ubiquitous Hitachi HD44780 controller, have a means to define a small number of custom characters. This facility can be used to advantage to build block graphics, from which the large numerals that span four lines can be defined. I'm sure that's how the chip that erco recommended does it; and it's how you could do it, too, within your Propeller chip, if you were inclined to dig into the programming. It all depends upon your objective: quick solution vs. learning experience.

-Phil

att_jay

Dear Phil
Just give me an idea to start from....

Thanks
Jay

Ravenkallen

You might start with basic interfacing of the LCD first(If you have not already done so?). Most HD44780 displays have only 8 custom characters to use, so you could have a digit 4x2 big. You would then have to rewrite the character RAM and display the next digit and so on. You would also have to do all of this beyond the human persistence of vision... I don't think that there is a object for this exact thing, but you might check the Obex. Good luck:)

att_jay

Thanks for your reply, Yeah I already have interfeced propeller with LCD and can even display some characters. But I want to customise the characters, instead of small (default) I want to write in 4 Big digits.... that covers 4 lines and all columns (evenly spaced).

Cheers
jay

Ravenkallen

What driver are you using? What mode are you operating in(4 bit or 8 bit parallel)? You want 4 big digits with a whole character spaced between them? So you want a 4x4 character then?

Edit: I just checked the Obex and there doesn't seem to be any object that supports that... Maybe i will make one in my spare time(When i am not learning C:))

RDL2004

Here is an example I found on the internet of big numbers intended for a 16x2 display that are created by using 8 custom characters. The 8 custom characters are the bottom row. This probably wouldn't look as good on a 20x4 due to the tight vertical spacing, but that could be fixed.

You should also keep in mind that those 8 custom characters can be changed on the fly by your software...

att_jay

Thanks Ravekallen,
Yes I am actually working in 8 bit parallel mode, where I am passing byte to the I/O port of LCD display. I want to display only 4 big numeric digits 0...9 evenly spaced that covers the LCD display ( 20x4).

I would highly apprecitae any kind of help in this regard.

Cheers
Jay

att_jay

Hi RDL2004,
Can you please send me the example code of this?

Thanks
Jay

RDL2004

Well, sorry but that bitmap was drawn from a photo of someone else's project on a different micro-controller. It was only meant as an example of how to combine just 8 characters together to form larger numbers. Each large digit is made from a combination of 6 of the different custom characters. I'm sure there is an HD44780 object somewhere in the Obex that can load custom characters into the LCD controller.

Shawn Lowe

I am working on getting a LCD to do just what your trying to do. I think you want to use a lookup table, like:

lookup (number)(eeprom location+number)
output lcd(char1,char2,char3,char4)

then in your eeprom table just list the custom characters. Of course this isn't working code, but I'm thinking this is how you would do it

Humanoido

This could be a good option: We went through some solutions for big characters on the Propeller TV driver for Big Brain software.
A search at the index here will bring up some options.

http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=977025&viewfull=1#post977025

and I found this link

#344

http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=982331&viewfull=1#post982331

att_jay

Shawn Lowe wrote: »

I am working on getting a LCD to do just what your trying to do. I think you want to use a lookup table, like:

lookup (number)(eeprom location+number)
output lcd(char1,char2,char3,char4)

then in your eeprom table just list the custom characters. Of course this isn't working code, but I'm thinking this is how you would do it

Thanks Shawn,

Could you please send me an example code that helps me in wirting some customized characters/shapes in eeprom and then display it on LCD for showing Big digits like e.g. 0, 1 etc.

Thanks
Jay