clueless with DMD

The Dot Matrix Display (DMD) is a 32x16 array of high-brightness LEDs for visually striking effects. [Product Page]
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jamescampbell
Posts:5
Joined:Tue Jun 17, 2014 8:36 am
clueless with DMD

Post by jamescampbell » Tue Jun 17, 2014 8:49 am

I may have bitten off more than I can chew here with my first ever foray into the world of programming being and Eleven and a DMD but hopefully you can help me with some trouble shooting.

Having just bough home this Arduino and having a play with the blink sketch, I've downloaded the suggested DMD demos, placed them into the arduino library folder on my mac and then uploaded the unchanged dmd_clock_readout example to my Arduino Eleven with the DMD plugged in (as per quick start guide), the TX and RX lights show the sketch is downloading and other sketches have worked but nothing shows up on the DMD at all (I am not running power to the DMD but apparently that is unnecessary.)

I have not seen a single LED light up in all my testing so far, should I have changed some of the parameters in the example sketch to make it functional (didn't see anything in the notes) should I assume that the DMD is faulty or is there another test I can do before taking it back to the shop?

Thanks to all,
James

Brissieboy
Posts:209
Joined:Fri Sep 20, 2013 7:25 am

Re: clueless with DMD

Post by Brissieboy » Wed Jun 18, 2014 2:40 am

jamescampbell,

Are you using the DMD library available here:
https://github.com/freetronics/DMD/

Do you get any errors when you compile the sketch?

Does it download to your Arduino correctly?

Make 100% sure that you have the DMD connected correctly. Did you make an incorrect connection at any time that may have caused damage?

Is there any physical damage to any part, including all the connectors?

Have you proven your Arduino is operational by running one of the very basic LED flash sketches? This is obviously the best place to start - don't try to be too clever too quickly.

You MAY be able to run your DMD without its own power supply, but I strongly advise against it. Use a separate 5 Volt power supply capable of at around 2 Amps per DMD. Running from the USB via the Arduino places both the Arduino and the DMD well outside their operating specs.

jamescampbell
Posts:5
Joined:Tue Jun 17, 2014 8:36 am

Re: clueless with DMD

Post by jamescampbell » Wed Jun 18, 2014 6:23 am

Hi Brissyboy,
Thanks for your input!

I had run basic blink tests, upload was working fine and all connections were good.

I've just come home from swapping the DMD at the shop and it seems that indeed the DMD was faulty!

Have also picked up a power supply while I was there and will be connecting it now.

Thank you for your help.

James

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