Need more than 8 user defined characters - Page 2 - Electronic Circuits Projects Diagrams Free

ericgibbs · 29th October 2007, 05:41 PM

Quote:

Originally Posted by Pommie

It doesn't work.

For the first number (2) you need 4 characters.
For the 3 you need an additional 2 characters - bottom 2.
For the 4 you need 3 more - all of them.

That's nine already and we're not even half way through.

Mike.

hi Mike,
I have just re-read my earlier post regarding '8 special characters', it is a little ambiguous, it could be read as implying that only 8 symbols could be used to represent all the numbers from 0 thru 9, thats not the case.

I have kept advising the OP that it would be necessary to create the symbols within the program in real time.

Although it isn't a brilliant display, it could be used to show a real time clock.

Regards

mcs51mc · 29th October 2007, 07:23 PM

Hi there,

Sorry Eric but I think I don't understand what you mean by:

Quote:

Originally Posted by ericgibbs

... it would be necessary to create the symbols within the program in real time...

I think I'm already doing that since I modify the user defined characters (udc) as I need them. Is this what you mean by "in real time"??
Problem is that, like Mike already mentioned, the address of the udc is written at the DDRAM addresses not the data of the udc itself.
So when I change one udc all DDRAM locations using that udc changes at the same time

I think your PIC simulator doesn't react like a real HD44780U does or I'm still missing something

I'm using 8051 system en program in assembler.

Attached a screen shot of the "Big Font" I planned to make

Gordz · 29th October 2007, 09:34 PM

What about taking a look at this :-

http://www.vega-xp.com/in/index.php?...d=78&Itemid=58

mcs51mc · 30th October 2007, 06:28 AM

I looked
I downloaded
Now I will study

Thanks a lot...

ericgibbs · 30th October 2007, 07:24 AM

Quote:

Originally Posted by mcs51mc

I looked
I downloaded
Now I will study

Thanks a lot...

hi mcs,
Do you understand the Basic language, I know there are many variants, but I will, if you are interested, post my draft copy of the Oshonsoft basic program I have been using for the special characters.

The OS LCD sim does respond in this application as per the HD44780.

If you examine my program, you will see for each digit, before its written to the LCD, the special character pattern
is loaded into DDRAM, it is then called using that special characters address.

I write the digit to its designated location on the LCD.

eg: consider 6 digits, representing the real time of day,
if I want to display the minutes 'tens', the program gets the digit for the time counter,
creates the special char pattern for 4 of the LCD pixel blocks, it then writes these 4 spec chars to location number 5 of the LCD.
Remember when you do it this way, only 4 LCD pixel blocks, require a new spec char, before its written to the display.

When dealing with these LCD's its a good idea to only re-write a digit to the LCD, when that digit has changed from its previous value.
There is no point in refreshing the whole display, if only one digit has changed.

Let me know what you like to do?

mcs51mc · 30th October 2007, 04:24 PM

Quote:

Originally Posted by ericgibbs

hi mcs,
Do you understand the Basic language, I know there are many variants, but I will, if you are interested, post my draft copy of the Oshonsoft basic program I have been using for the special characters.
The OS LCD sim does respond in this application as per the HD44780.

If you examine my program, you will see for each digit, before its written to the LCD, the special character pattern
is loaded into DDRAM, it is then called using that special characters address.

I write the digit to its designated location on the LCD.

Beside 8051 based µC I also program PC software in VB6.0 & LabView, so you can always post your draft and I will look into it.

Quote:

Originally Posted by ericgibbs

eg: consider 6 digits, representing the real time of day,
if I want to display the minutes 'tens', the program gets the digit for the time counter,
creates the special char pattern for 4 of the LCD pixel blocks, it then writes these 4 spec chars to location number 5 of the LCD.
Remember when you do it this way, only 4 LCD pixel blocks, require a new spec char, before its written to the display.

Absolutely, one digit equals 4 user defined characters.
When you only write one character that has changed, you need only four user defined characters. It's meaningless to always overwrite the whole LCD. I agree with you for the full 100%

But... ...
When you change a user defined character all LCD locations that are using those four user defined characters are also changed. Even if you don't explicitly write to those locations, they will change on the LCD.
eg. user defined character 1 is used in positions Line1, pos5; Line1, Pos10; Line2, Pos3 and Line2, Pos16 (it's just an example, has nothing to do with your clock or my "big font"). Changing user defined character 1 will result in an immediate change of all four LCD positions mentioned above without any write actions to those locations!!!

Apparently the controller is continously updating the LCD display, and that is something your LCD simulator doesn't do (I think)!

Quote:

Originally Posted by ericgibbs

When dealing with these LCD's its a good idea to only re-write a digit to the LCD, when that digit has changed from its previous value.
There is no point in refreshing the whole display, if only one digit has changed.

Here again I agree for the full 100% with you. In all my previous projects I only write data that has changed on the LCD

.

ericgibbs · 30th October 2007, 05:08 PM

hi mcs,
In that case, using a 2 Row LCD isn't going to get the job done.

If you live in the UK, I will send you a 1 * 8 LCD display, with large 11mm high characters, with my compliments,
this should give the result you are looking for.

I have a number of these LCD's on the shelf, they use the standard HD44780 controller and have an LED back light.

If you you are interested, PM your address and I will forward one,, FOC.

Regards

Gordz · 31st October 2007, 06:29 AM

Hi Eric, did you get those localy ? They are exactly what I need for a project I am working on for displaying Volts and Amps and a *much* better option than using two 2*16 !

ericgibbs · 31st October 2007, 07:58 AM

Quote:

Originally Posted by Gordz

Hi Eric, did you get those localy ? They are exactly what I need for a project I am working on for displaying Volts and Amps and a *much* better option than using two 2*16 !

hi,
They are from Farnell Leeds or RSComps, about £10's ish.

Its a common type, they also come in 1 * 16

I'll see if I can dig out the delivery notes etc.

blueroomelectronics · 31st October 2007, 11:56 AM

Or a small VFD display like this Noritake

mcs51mc · 31st October 2007, 04:54 PM

Hi Eric, Thanks for your offer but I'm not living in the UK. The LCD I'm using has 8mm characters, so I expected a 16mm height font.

Hi Blueroom, Definitely something to look for. Too bad I can't use my LCD library with that one

ericgibbs · 31st October 2007, 05:49 PM

Quote:

Originally Posted by mcs51mc

Hi Eric, Thanks for your offer but I'm not living in the UK. The LCD I'm using has 8mm characters, so I expected a 16mm height font.

Hi Blueroom, Definitely something to look for. Too bad I can't use my LCD library with that one

hi mcs,
To set the record straight, you were correct, reference the LCD Sim, it dosn't obey the 'only 8 special char rule'.

Decided to program a PIC, got a repeated character!.

We live and learn.

Is it possible that you can give your location?

mcs51mc · 31st October 2007, 07:22 PM

Quote:

Originally Posted by ericgibbs

We live and learn.

We have a saying overhere that I could translate as "Every day that you didn't learn a thing is a lost one." Today wasn't a lost one for you

Quote:

Originally Posted by ericgibbs

Is it possible that you can give your location?

I live in the Dutch part of Belgium.

Gordz · 31st October 2007, 09:10 PM

Thnx Eric, I'll look through the Farnell catalogue.

ericgibbs · 1st November 2007, 07:56 AM

Quote:

Originally Posted by Gordz

Thnx Eric, I'll look through the Farnell catalogue.

hi,
If you need more specification info, let me know.

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29th October 2007, 09:34 PM	(permalink)
Gordz	What about taking a look at this :- http://www.vega-xp.com/in/index.php?...d=78&Itemid=58

30th October 2007, 06:28 AM	(permalink)
mcs51mc	I looked I downloaded Now I will study Thanks a lot...

30th October 2007, 05:08 PM	(permalink)
ericgibbs	hi mcs, In that case, using a 2 Row LCD isn't going to get the job done. If you live in the UK, I will send you a 1 * 8 LCD display, with large 11mm high characters, with my compliments, this should give the result you are looking for. I have a number of these LCD's on the shelf, they use the standard HD44780 controller and have an LED back light. If you you are interested, PM your address and I will forward one,, FOC. Regards __________________ Eric "Good enough is Perfect" PIC tutorials: Gramo's: www.digital-diy.net/ Bill's: www.blueroomelectronics.com/

31st October 2007, 06:29 AM	(permalink)
Gordz	Hi Eric, did you get those localy ? They are exactly what I need for a project I am working on for displaying Volts and Amps and a much better option than using two 2*16 !

31st October 2007, 11:56 AM	(permalink)
blueroomelectronics	Or a small VFD display like this Noritake __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com

31st October 2007, 04:54 PM	(permalink)
mcs51mc	Hi Eric, Thanks for your offer but I'm not living in the UK. The LCD I'm using has 8mm characters, so I expected a 16mm height font. Hi Blueroom, Definitely something to look for. Too bad I can't use my LCD library with that one

31st October 2007, 09:10 PM	(permalink)
Gordz	Thnx Eric, I'll look through the Farnell catalogue.