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Author Topic: Dimming multiple led`s with Uno is it possible please?  (Read 438 times)
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Hi guys
New to the forum and Arduino`s  smiley. I need to make a light panel to cover the end of a 120mm telescope to create flat images for image processing. I have an Arduino Uno with quite a few components, led`s resistors etc and wondering if an Arduino Uno board would be able to control and dim as needed up to 13 led`s?. The led`s would be mounted somehow on a cap and fitted behind a diffuse panel to get an even light source at the end of the scope but I would need to have it dimmable to get a certain luminance. I notice some code for a single led comes with the Arduino software can this be used for 13 led`s please?
Thanks
Steve
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I don't think you connected the grounds, Dave.
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Do the LEDs have to be individually dimmed, or are they ganged on a single dimmer?
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Ganged on a single dimmer if poss. I need an even illumination right across the panel!
Cheers
Steve
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I don't think you connected the grounds, Dave.
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In theory, you can get a maximum of 256 levels of dimming with 8 bit PWM, but in practice you won't discern anything like that many.
You'll probably also need some form of driver circuit to drive that many LEDs, though you could maybe hang two LEDs per PWM pin.
Does it matter that the dimming will at only about 500Hz?
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I don`t think it should matter its the actual light level it gives in the camera. Its a very sensitive `cooled` astro camera so a bright light is not needed.
I just didn`t want to knacker the Uno board driving that many led`s, how many PWM pins are there please?. I`ve had the Arduino Uno a while and couldn`t think of a use for it until now  smiley Maybe I could get away with 10 or less I`d have to try it!
Thanks for your help AWOL
Steve
« Last Edit: July 25, 2013, 11:57:23 am by gasman » Logged

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I don't think you connected the grounds, Dave.
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There are six PWM pins 3,5,6,9,10 and 11
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Great I`ll have a try with that tonight, much appreciated.
Thanks again
Steve
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