Compact DC SSR for LED Canes

David_AVD

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I've bought a bunch of the Kmart 71cm candy canes. They are empty (no lights), but come with a ground stake that has the wiring channels built in. These canes seem to be a good size to insert (LED) lights into, and IMO would look great when at least 6 - 8 are used together.

Now, what I plan to do is design a small controller PCB to fit into the base of each cane. It would have DMX input and each one would be individually addressable to allow for some more detailed sequences. I also plan to add cable tails to each with the male end being input and the female being the output / loop through.

Driver chips tend to come in 8 or 16 output counts. Some preliminary LED placement tests show that 8 LEDs may not be enough to fill the tube well, but 16 is probably too many. So, maybe a 16 output driver with only 10 or 12 actually used may be the best option. I have thought about driving the LEDs directly from a PIC chip, but power dissipation could be an issue. Using a driver chip also means the power supply can be higher than 5V.

I have thought about breaking the design up into two boards; one for the DMX input and processing and the other for the LED driver. This would possibly reduce the overall cost, but means that you'd need to have a separate control box between the DMX stream and the first cane. It may also require more wires between canes than DMX would use. I do like the idea of DMX controlled elements that don't need external support electronics.

I did try fitting some WS2801 pixels into the canes as they are a great price per node, even if you only used the red portion. The main problem is that I think the 4 wire flat cable will cause quite a shadow in the tube. I don't have a 2801 controller handy at present to confirm this though. You'd also need to run the end of each section back to the base for feeding to the next cane which will add yet more shadows.

Anyway, these are just my musings on the subject. Sometimes it's good to write these ideas up publicly and get comments before committing to a specific course of action! :)
 

kevr

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Sounds like a great idea to me, I spotted these in Kmart a couple of months ago and bought a load of them for a rainy day. I have just left the Kmart boxing day sale to see what was there and got a few more LED's but no more candy canes.

I will be watching with anticipation to see what you come up with.

Kev :)
 

David_AVD

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I rarely use breadboard these days. Usually PCB first go for any project. The PCB is at work so can't take a picture just now. Sorry.
 

Blickensderfer

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David,
To bring this topic back up. I would be interested in 84 plus a couple spares after your redesign. In my setup, the PCB doesn't have to fit up inside the candy cane.
Thanks,
Dan
 

David_AVD

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Here's what the current board looks like:





I could look at an updated version (so the regulator can sit on the top side) and offer them here as a board only buy.
 

JPB

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David, are you going to stock these and if so do you have a rough idea of price?

I am thinking of redoing my candy canes for 2012 so that I can run them as normal candy canes or as vu-meters (I think that is what they are called) .

Jon
 

David_AVD

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I'll be revisiting this design in the new year, so will advise once I've got something nailed down.
 
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