Help need to build scrolling led dispaly....

[koolguy]

HI,

I need to build small scale without keypad scrolling text display by using PIC starting from PIC16f676....
I have seen it working as scanning from left right like that.

please guide me further!!

Thanks

 

[Ian Rogers]

Hi Ritesh..... I wish you would move away from that device... 64 bytes of ram is hard to work with..

Nigel's tutorials has one of these... see my signature..

 

[ronsimpson]

If you start a design out with very little RAM and only 14 pins you will have problems.

If is much batter to start out with some extra pins and a part with too much RAM. Many of the PICs have parts that are pin compatible and have three sizes of RAM and FLASH. Start out with the big part and after it is working look to see what it takes to use the smaller part.

Do not start out with the small part and when it is not working wish you had the bigger part and there is no pin compatible bigger part.

 

[koolguy]

OK, i will start with PIC16f88A....

 

[Ian Rogers]

Can you get hold of pic16f628 or 648's? These are the main pic16f84a replacements with more of memory.

 

[edeca]

https://www.best-microcontroller-projects.com/led-dot-matrix-display.html has a good explanation of how to build the hardware.

https://www.waitingforfriday.com/index.php/16x8_LED_Matrix_Display and https://www.jbprojects.net/projects/led/ might give you some inspiration for what is possible.

The software is not hard, very similar to writing code for a graphic LCD. But like ronsimpson says you will need more RAM, especially if you want to do scrolling text without writing very complicated code.

You can see something similar I did here: https://www.youtube.com/watch?v=YPOvv_sZ7Rw and the PCB version here https://www.youtube.com/watch?v=nZvTu3tt1g8&feature=plcp - this was the first project I did using the PIC.

 

[koolguy]

OK, in this site https://www.jbprojects.net/projects/led/ he talk about that software please tell about that...

 

[edeca]

It would be best if you did some research and came back with specific questions. We cannot do the whole project for you from scratch.

 

[Ian Rogers]

Ritesh........... Its all done for you....

 

[Mike - K8LH]

If you start a design out with very little RAM and only 14 pins you will have problems.

Really? Can you elaborate on what kind of problems he will have, please?

 

[colin55]

Here's a 15x7 Display with surface-mount components:
**broken link removed**

Here's the same one from a constructor:
**broken link removed**

and another version:
**broken link removed**

<snip>

 

[koolguy]

cool............

 

[koolguy]

HI again,

Please provide Hi tech C complirer open source link for downloading it...

thanks

 

[Ian Rogers]

**broken link removed**

The light version is the same as the pro... the optimization runs out after a month...

 

[koolguy]

Hi,

I have downloaded the 3rd file but i have not found set up file after extracting it..

 

[Ian Rogers]

The third one is for OS X Apple! Windows is the top one.... If you have installed MPLAB then Hitech should have been installed, unless you said no.

 

[koolguy]

is that trial version b'coz asking for activation...

 

[Ian Rogers]

Don't select activation.... Run it as demo... After a month it will resort to lite....

 

[koolguy]

OK, i have installed plaese tell how to start simple C program and test it like blink LED..!!

 

[Ian Rogers]

you can copy any of the tutorials in my signature.

Nigel's tutorials.. re-written in C. https://www.electro-tech-online.com/articles/nigel-goodwins-tutorials-in-c.467/

Use a pic16f676 if you like.

#include<htc.h> // definitions are here
#define _XTAL_FREQ 4000000

void main()
   {
   TRISA = 0;
   while(1)    // loop forever
      {
      RA0 = 1;  //porta.0 on
      __delay_ms(200);
      RA0 = 0;  //porta.0 off
      __delay_ms(200);
      }
   }

Something like this .... If the 676 has a comparator, then add the line CMCON = 7;

Thanks for the heads up edeca!!!