Need more than 8 user defined characters

[mcs51mc]

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.

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)!

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]

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]

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]

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]

Or a small VFD display like this Noritake
**broken link removed**

 

[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

 

[ericgibbs]

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]

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

Is it possible that you can give your location?

I live in the Dutch part of Belgium.

 

[Gordz]

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

 

[ericgibbs]

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

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

 

[Gordz]

Will do, thanks again. I've shelved that project though until I finish my PIC24HJ based 'scope.

 

[mcs51mc]

This is a possible solution I found after "puzzling" a lot
Not directly what I was looking for but it's a start.
I also tried to use the cursor as lower horizontal bar but it wasn't satisfying also
The aspect ratio can be improved a bit by not using upper line of upper character and lower line of lower character.

 

[ericgibbs]

hi mcs.
That is passable for a 'time clock' display.

I'll give it a run tomorrow, let you know how it goes.