Search found 173 matches

by Brissieboy
Sun Jan 12, 2014 3:47 am
Forum: Dot Matrix Display
Topic: Project housing ideas
Replies: 9
Views: 4974

Project housing ideas

I am at the stage in my project where I need to think seriously about how I am going to house and mount my project. I have 2 DMDs side-by-side with an Arduino and some miscellaneous bits to mount, and I need to have a rugged, weatherproof, outdoor housing suitable for vehicle roof-top mounting. I am...
by Brissieboy
Mon Dec 30, 2013 11:36 pm
Forum: Dot Matrix Display
Topic: Wrong AC adaptor = Fried DMD?
Replies: 7
Views: 4378

Re: Wrong AC adaptor = Fried DMD?

OOPS!!

I made a silly mistake in the above post!!

There are actually 512 LEDs per DMD - not 256!!

You will need a power supply capable of delivering 4 Amps for a single DMD.

Sorry for the misleading information.
by Brissieboy
Mon Dec 30, 2013 5:32 am
Forum: Dot Matrix Display
Topic: Wrong AC adaptor = Fried DMD?
Replies: 7
Views: 4378

Re: Wrong AC adaptor = Fried DMD?

SrBatracio, Most small AC adaptors have a thermal sensor included within the windings which go open circuit when they reach their designed temperature. This is most likely what has happened to your unit as it would have been well overloaded trying to drive more than a handful of LEDs. The DMD should...
by Brissieboy
Sun Dec 22, 2013 4:36 am
Forum: Dot Matrix Display
Topic: LED module pin assignment
Replies: 9
Views: 20961

Re: LED module pin assignment

stryker, Just a thought based on my experience: If you're using the SPI clock as suggested by TheRevva above (using SPI_CLOCK_DIV64) and the default timer initialisation of 5000 uSec, you might be running out of time in the interrupt routine. I'm using SPI_CLOCK_DIV2 and the interrupt takes about 44...
by Brissieboy
Mon Nov 04, 2013 5:45 am
Forum: Dot Matrix Display
Topic: DMD and SD card help
Replies: 2
Views: 2026

Re: DMD and SD card help

LXl15, Haven't looked at your code, but how much are you powering from the USB connection? Might pay to check the voltage on the board. The DMDs will load it down WAY too much - must be powered separately. Not sure on the load demand from your other peripherals, but it might be worth a quick check. ...
by Brissieboy
Fri Nov 01, 2013 6:09 am
Forum: Dot Matrix Display
Topic: DMD documentation issue
Replies: 1
Views: 2468

DMD documentation issue

There appears to be an error in some of the documentation around the Freetronics DMDs. The DMD Connector board supplied with the DMDs has the output enable pin designated as 'nOE'. This is incorrect - it should be 'OE'. It is active HIGH. The schematic has the same error. The the DMD library also co...
by Brissieboy
Sun Oct 20, 2013 2:57 am
Forum: Dot Matrix Display
Topic: Limited scrolling in DMD?
Replies: 2
Views: 2411

Re: Limited scrolling in DMD?

Thanks stryker. I was hoping that somebody might have already delved into this so I don't have to re-invent the wheel. This is not a trivial task (at least not for me). I have already had a quick look at the library and have already added a little functionality that I needed: 1. Allowed for a space ...
by Brissieboy
Sat Oct 19, 2013 1:54 am
Forum: Dot Matrix Display
Topic: Limited scrolling in DMD?
Replies: 2
Views: 2411

Limited scrolling in DMD?

Has anyone done any work on the DMD library to allow for scrolling over a limited area of the DMDs?
I would like to be able to scroll (drawMarquee) while leaving a few columns of pixels at one or both ends (of a pair of DMDs) for other purposes.

Brissieboy
by Brissieboy
Fri Oct 11, 2013 4:54 am
Forum: Dot Matrix Display
Topic: Font header file construction
Replies: 8
Views: 7283

Re: Font header file construction

Thanks for all the info angusgr. I suspected that most of the header information was redundant. I was unable to find anywhere that it was used in the library. I have had a play with GLCD Font Creator, but as far as I can tell it does not correctly handle proportional fonts over 8 pixels high. It cou...
by Brissieboy
Thu Oct 10, 2013 3:41 am
Forum: Dot Matrix Display
Topic: Font header file construction
Replies: 8
Views: 7283

Re: Font header file construction

And where in the file is the character spacing specified?