# RGB Leds and Medusa DMX or other boards



## Devils Chariot (May 23, 2007)

I bought the Medusa DMX controller and I want to use it to fade and strobe some RGB leds to light up the eyes of my 3 axis skull.

I can use the Medusa to successfully turn on/off/fade single color leds but I can't seem to figure out the wiring on the RGB leds I bought. I understand how they work I just I don't understand how they need to be wired to work with the Medusa DMX.

If you look at the picture and read the manual for the Medusa you see that the ground goes into the board and then the power connects to the LED.










I am thinking that it doesn't work because the power is going into the cathode in my setup. The board is switching the anodes to complete the circuit to control the leds. However, I am perplexed as to how you would power this led. I would think it needs switched power inputs and not switched grounds since the LED has a fixed polarity.

Can you guys take a look at what I have and see if there is a way to make these leds work with the Medusa. I attached the tech specs on the leds as an attachment.

Thanks for any help you can give.

- Craig


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## pshort (May 6, 2008)

It depends on whether your LEDs are common anode or common cathode. If your board is truly switching the anodes as you stated when using individual LEDs (i.e. you're connecting the cathodes to ground), then you would need common-cathode LEDs. Common anode RGB LEDs won't work in that case.


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## pshort (May 6, 2008)

Further comment...

I'm not so sure that you are actually switching the anodes. From the manuals on this page it appears that you are supposed to switch the cathodes (i.e. tie all of the anodes to +5V through series current-limit resistors). If that is truly the correct web page for the device that you've purchased, you need common-anode RGB LEDs, with that common anode connected to +5V (not to ground).


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## tstraub (Feb 26, 2012)

I have never used that controller but I did take quick look at the documentation. It seams that the outputs are sink only. You could probably use some PNP transistors to make it work with your current LEDs but considering that you would need to buy transistors to make it work it really not worth the effort.

The easiest way to get it working would be to buy some common anode LEDs and connect them as the picture you linked. Here is a link to some LEDs that should work for your needs. http://www.taydaelectronics.com/review/product/list/id/2883/ I have used these LEDs in some of my projects and the quality is quite good for the price in my opinion. The LEDs are cheap enough I would just get different LED and save to common cathode ones for a future project

Tyler


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## Devils Chariot (May 23, 2007)

tstraub said:


> I have never used that controller but I did take quick look at the documentation. It seams that the outputs are sink only. You could probably use some PNP transistors to make it work with your current LEDs but considering that you would need to buy transistors to make it work it really not worth the effort.
> 
> The easiest way to get it working would be to buy some common anode LEDs and connect them as the picture you linked. Here is a link to some LEDs that should work for your needs. http://www.taydaelectronics.com/review/product/list/id/2883/ I have used these LEDs in some of my projects and the quality is quite good for the price in my opinion. The LEDs are cheap enough I would just get different LED and save to common cathode ones for a future project
> 
> Tyler


I think your right. My LEDs have the common cathode which is backwards for the way the board appears to be set up. I'll pick some up and see if i Can get em working.

Thanks for the help!


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## Devils Chariot (May 23, 2007)

Thanks guys fro your help. I bought some common anode leds today and its working!


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## pshort (May 6, 2008)

Glad to see that you've got it working.


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