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DIY Moving Message Display

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www.woe.onlinehome.de/e-project.htm

ME said:
Look in the newest issue of the Elektor Electronics magazine (November 2003):
http://www.elektor-electronics.co.uk/ln/details/e1103u.htm
There's an article about a Running Text Display using an 89S8252 Flash MCU.

PCB layout and source & hex code can be downloaded here:
**broken link removed**
Click to expand...
I have attached the article from Elektor November 2003.
 
16x16 matris led

Here you have a big LED (640) that used the LCD CHIP.
All prog that used the LCD interface can use this big display.
**broken link removed**
 

89c51 based moving message display softwa

Or check my project:

**broken link removed**

(not finished yet... stardate: 25/03/2004, but lots of info already)

**broken link removed**
 

moving message display using 89c51

Hi,

I am working with 8051 core like atmel, first i will say what kind of hardware ( like multiplex or shift resister based?) if u build multiplex then the brghtness will down because when u build large tipe of display scaning speed will be fast, or i f u want to build shift resister based (like 74hc164) it out put 8 led , its brightness will fine, and no matter how long u want to made, second , if u write a programme with ascii code for latter then it will so easy for u, like A=41, u also write 16 line ,32 line moving display another language.


Masud Rana
Matrix Electronics fourm
Dhaka
Bangladesh
 

modular matrix display elektor

I'm a begginer is this things. I had understand everything except the following: (not good at C)

How do we convert the ascii char (for instance A is 7E 88 88 88 7E 00)
that is show up in columns, into data to be shift in to the rows?

A basic code example will be apreciated. Thanks

CM.
 

74hc164 led

Codeman said:
I'm a begginer is this things. I had understand everything except the following: (not good at C)

How do we convert the ascii char (for instance A is 7E 88 88 88 7E 00)
that is show up in columns, into data to be shift in to the rows?

A basic code example will be apreciated. Thanks

CM.
Click to expand...

its all explained above see the main C function,
basically all you do is shift bits in each byte up or down before
sending them to the display, (see main() function in my C code)
i keep an array with all bytes of the message stored there.

this way i can shift message up / down and left /right

the oher way of doing it would be to display one column at a time instead
of one row like i did and again to shift message up/down u do that bit
shifting with each byte of the message

hopw this helps

let me know if not ;)) ill try to explain it better
 

assembly code for moving message display

Well I dont understand very well C. :oops:
If you can isolate the function that converts the "A" char ( 7E 88 88 88 7E 00 ) that is see in columns into row shifts I will be gratefull.

TIA
CM
 

moving message diy

MAX7221 for 7-seg display (8 digits) and MAX6952 for 5x7 matrix (4 digits).
Nice products, simple interface, only 4 wires to uC.

josiphal
 

microcontroller based scrolling message display

OK Folks

Here is the complete Elektor June 2001 Zip file for the Modular Dot Matrix display including the software.
 

diy led moving message display circuit diagrams

Here is another nice circuit using a Zilog chip, circuit schematic and software included. I am not sure whether the chip is still available, but for all you experts out there, maybe you can adapt to another microcontroller.

/ PDF deleted, always search google before uploading files. Read forum rules before posting!

This is an application note from Zilog, still available at their web site:
https://www.zilog.com/docs/z8/appnotes/an0078.pdf

- ME
 

software für moving message

Hi rojo, I read your article ,there are somethings i do not understand.
LED_DATA = (ledArray & row) ? 1 : 0;
the above code "? 1 : 0" i don't know what its means! i am a pic user.
 

zuisti pic16f628 msg display pcb layout

lgeorge123 said:
Hi rojo, I read your article ,there are somethings i do not understand.
LED_DATA = (ledArray & row) ? 1 : 0;
the above code "? 1 : 0" i don't know what its means! i am a pic user.
Click to expand...


Code: 
LED_DATA = (ledArray[i] & row) ? 1 : 0;
is the same as:
Code: 
if (ledArray[i] & row)
   LED_DATA = 1;
else
   LED_DATA = 0;


The following is quote from page 65-66 of my C++ book with the title "C++ How to Program, 3rd ed.":
`C++ How to Program´ said:
Code: 
if ( grade >= 60 )
   cout << "Passed";
else
   cout << "Failed";
...
C++ provides the conditional operator (?:) that is closely related to the if/else structure. The conditional operator is C++'s only tenary operator - it takes three operands. The operands, together with the conditional operator, form a conditional expression. The first operand is a condition, the second operand is the value for the entire conditional expression if the condition is true and the third operand is the value for the entire conditional expression if the condition is false. For example, the output statement
Code: 
grade >= 60 ? cout << "Passed" : cout << "Failed";
contains a conditional expression that evaluates to the string "Passed" if the condition grade >= 60 is true and evaluates to the string "Failed" if the condition is false. Thus, the statement with the conditional operator performs essentially the same as the preceding if/else statement. As we will see, the precedence of the conditional operator is low, so the parentheses in the preceding expression is required.
The values in a conditional expression can also be actions to execute. For example, the conditional expression
Code: 
cout << ( grade >= 60 ? "Passed" : "Failed" );
is read, `If grade is greater than that or equal to 60, then cout << "Passed"; otherwise cout << "Failed".´ This too, is comparable to the preceding if/else structure. We will see that conditional operators can be used in some situations wheres is/else statements cannot.
Click to expand...
This info can be found in every C and C++ programming book.
 

moving sign diy

dataPtr=&led_chars[message[0]-0x20][0] , i don't know the meaning
of [message[0]-0x20][0], why should it -0x20??????????
 

scrolling message display driver

Hi

I'm new here and I want to use max6952. Is there anyone know how?
 

diy led message display circuit diagrams

lgeorge123 said:
dataPtr=&led_chars[message[0]-0x20][0] , i don't know the meaning
of [message[0]-0x20][0], why should it -0x20??????????
Click to expand...

ok, its very simple, each character is defined by 6 bytes (5 bytes for each column + 0x00 for the space between characters), those 6 bytes are stored in led_chars array, message[] array contains the message to be displayed i.e. ASCII codes of each character of the message is stored
in message[] array, now to get to the actual bytes that define each character from the led_chars[] array i need to get the array index that
points to the first byte of character definition in the led_chars[] array,
as ASCII codes for alphanumeric characters start at 0x20 hexadecimal
or 32 decimal, and because index of led_chars[] array starts from 0
i have to submit 32 i.e 0x20 from each character`s ASCII code.
 
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