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Re: Dot Matrix Display

Posted: Wed Dec 26, 2012 9:38 pm
by 42n8
breeti109 wrote:I've attatched the libray I made here. I've added some compatibility headers for arduino, based on the original library, but I have no idea if it will work properly on arduino.

Attachments
dmd_distrib_v100.7z
(15.24 KiB) Downloaded 46 times

I just happened to have a PIC18F4550 lying around...

This code doesn't work as presented, yet we can clearly see that it does. The uploaded version must not be the final version. There is an error in scrollingtext.c :- "message is undefined" Go to line 135 and change the word message to message1.

There are also some configuration errors apparent that relate to other PIC18F types and not to the 25xx or 45xx devices specified in the article, however they are valid in other contexts. Ideally thse could be set up as hardware definitions.

They are "BOREN" and "OSC". This latter "OSC" variable is assigned the non-existant value "INTIO67"

Similarly, the real config variables CCP2MX and OSCTUNE are asigned values that don't exist. They are "PORTBE" and "PLLEN" respectively.



Regards

Re: Dot Matrix Display

Posted: Wed Dec 26, 2012 11:35 pm
by 42n8
These are the settings for my application, yours may differ. These settings are required for use with a 20MHz crystal oscillator and a 32 MHz PLL driven CPU oscillator which allows me to manipulate the displays via USB under the control of a C# application program.

All of the settings are within scrollingtext.c and have been verified to work.

I modified the first few lines as below.

Code: Select all

#pragma config PLLDIV   = 5                  // 20Mhz external oscillator
#pragma config CPUDIV   = OSC2_PLL3    // 32 MHz CPU osc (96MHz PLL/3)
#pragma config USBDIV   = 2                 // Clock source from 96MHz PLL/2
#pragma config FOSC     = HSPLL_HS      

//#pragma config OSC 	= INTIO67
//#pragma config BOREN 	= OFF

#pragma config WDT 	= OFF
#pragma config MCLRE 	= ON
#pragma config PBADEN 	= OFF
#pragma config CCP2MX 	= ON


Next fix the OSCCON and OSCTUNE commands as shown below.

Code: Select all

		OSCCONbits.IRCF2 = 0;
		OSCCONbits.IRCF1 = 1;
		OSCCONbits.IRCF0 = 1;
		OSCTUNEbits.INTSRC = 0;
Finally,
Never remove lines from example code because that statement or function may become useful to you when, at some future time, the issues with it have been cleared away.

Hope this explains why the library didn't work and resolves the problems that some of you experienced.

Many thanks for the fantastic work of the original author, T Breed (AKA breeti109).


Regards

Re: Dot Matrix Display

Posted: Mon Jan 07, 2013 2:02 pm
by Makanaki
Hi guys, I´m new to this DMD panel. I mostly use microchip 18F series but I don´t understand any word of C, always use Picbasic to make my own projects. I would apreciate to have a compiled test for 18F452 because I got a DMD panel but before to start making some experiments I want to know that my DMD panel is in working condition.
This is my configuration:
- 20Mhz external clock.
- PortB.0 = OE
- PortB.1 = CLK
- PortB.2 = SCLK
- PortB.3 = R (data)
- PortB.4 = A
- PortB.5 = B

If someone is interested I got a schematic of the DMD panel in Word format so I can share without problem.

Thank you.

Re: Dot Matrix Display

Posted: Tue Jan 08, 2013 1:44 am
by bwooce
Makanaki wrote:If someone is interested I got a schematic of the DMD panel in Word format so I can share without problem.
Yes please!

Re: Dot Matrix Display

Posted: Tue Jan 08, 2013 10:35 am
by Makanaki
Here it is, I don´t know if it matches panel revision. Anyway I think minor changes were made to latest versions so it is useful.

It´s rar format because the doc isn´t allowed.

Re: Dot Matrix Display

Posted: Tue Jan 08, 2013 11:01 am
by djosfra
How do I connect display to LAN?

Re: Dot Matrix Display

Posted: Tue Jan 08, 2013 11:05 am
by djosfra
Has anyone tried this one ? Seems easier to connect than etherten , it has a display port
http://kickstartelectronics.com/?p=30

Re: Dot Matrix Display

Posted: Fri Dec 05, 2014 10:07 am
by Nithinkk
Hi Breeti109,
I am working with your DMD library download/file.php?id=18 using Tiva C microcontroller(TM4C123gXL launchpad) from TI. I had already ported the code to Keil MDK v5, there I had got lot's of confusion during porting,because I am not much familiar with C18 compiler dependent keywords.There I had used just only 1 panel for checking but failed to display character's on display.I am attaching my source code along with this. Can you please go through and find anything wrong in this. The project main file is qs-rgb and I had used lot's of API's from TI for programming, may not be open fully on your computer without Tivaware peripheral library. But that dosen't matter, I want to know whether the logic which I had written is correct or not. When checked in the 32*16 DMD I can find from the watch window that SPI data out is wrong. Can you please tell how the *p gets the data from panels[0]?. There is enough memory available in Tiva C microcontroller for storing the glyphs data, so I dosen't need to find any additional storage space. I am eagerly waiting for your reply and welcoming others reply as well..

Re: Dot Matrix Display

Posted: Sat Dec 06, 2014 3:44 am
by Brissieboy
Nithinkk,

I haven't checked your code - I think you are asking a bit too much with that request on this forum considering your somewhat esoteric development environment.

But have a look at this thread. It explains a bit on how the DMD works. It may help you a little.

Re: Dot Matrix Display

Posted: Wed Jan 27, 2016 11:47 am
by vishalgupta1991
How to make regional font for dot matrix display(32*16 matrix).