Dot Matrix Display

The Dot Matrix Display (DMD) is a 32x16 array of high-brightness LEDs for visually striking effects. [Product Page]
42n8
Posts: 46
Joined: Wed Dec 26, 2012 8:10 pm
Location: Auckland, NZ

Re: Dot Matrix Display

Post by 42n8 » Wed Dec 26, 2012 9:38 pm

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
Last edited by 42n8 on Thu Dec 27, 2012 11:55 pm, edited 3 times in total.

42n8
Posts: 46
Joined: Wed Dec 26, 2012 8:10 pm
Location: Auckland, NZ

Re: Dot Matrix Display

Post by 42n8 » Wed Dec 26, 2012 11:35 pm

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

Makanaki
Posts: 3
Joined: Mon Jan 07, 2013 1:01 am

Re: Dot Matrix Display

Post by Makanaki » Mon Jan 07, 2013 2:02 pm

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.

bwooce
Posts: 21
Joined: Mon May 28, 2012 11:15 am

Re: Dot Matrix Display

Post by bwooce » Tue Jan 08, 2013 1:44 am

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!

Makanaki
Posts: 3
Joined: Mon Jan 07, 2013 1:01 am

Re: Dot Matrix Display

Post by Makanaki » Tue Jan 08, 2013 10:35 am

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.
Attachments
P10sch.rar
DMD Schematic
(254.97 KiB) Downloaded 373 times

djosfra
Posts: 2
Joined: Tue Jan 08, 2013 10:57 am

Re: Dot Matrix Display

Post by djosfra » Tue Jan 08, 2013 11:01 am

How do I connect display to LAN?

djosfra
Posts: 2
Joined: Tue Jan 08, 2013 10:57 am

Re: Dot Matrix Display

Post by djosfra » Tue Jan 08, 2013 11:05 am

Has anyone tried this one ? Seems easier to connect than etherten , it has a display port
http://kickstartelectronics.com/?p=30

Nithinkk
Posts: 1
Joined: Fri Dec 05, 2014 4:42 am

Re: Dot Matrix Display

Post by Nithinkk » Fri Dec 05, 2014 10:07 am

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..
Attachments
NEW 2 LED MATRRIX DISPLAY 74HC595 INTERFACING USING SPI FREESCALE - Copy.rar
DMD
(511.93 KiB) Downloaded 223 times

Brissieboy
Posts: 94
Joined: Fri Sep 20, 2013 7:25 am

Re: Dot Matrix Display

Post by Brissieboy » Sat Dec 06, 2014 3:44 am

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.

vishalgupta1991
Posts: 9
Joined: Fri Oct 30, 2015 12:02 pm

Re: Dot Matrix Display

Post by vishalgupta1991 » Wed Jan 27, 2016 11:47 am

How to make regional font for dot matrix display(32*16 matrix).

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