DIY LED driver for reef lighting

Yes, every driver board would have it's own dimming timing. If I give every board it's own controller to sync them all is going to be PITA plus I would love to control them all from one MC so to program cloudy days, storms etc...
 
If you want a sunrise/sunset from say right to left on a long tank you could probably make due with 6 dimming sets (3 of white, 3 of blue) and 6 PWM channels (read the specs to get one with enough). I think the mega has 14 PWM channels... I know the Fez Panda II (not an Adruino, but a .netmf board) has 6 PWM channels.

I think there are some shields that give you tons of extra PWM channels too, so really if you wanted every single string individually dimmed i am sure you could do it eventually.

I think it would take some creative stringing to make clouds and storms not look like strings yet still have rows for sunrise/sunset. The best thing i could think of, for storms, is to spread them very far apart, a mix of blue and white, and not use them until sunrise/sunset has reached past the all of the storm string and then start to turn them up too.
 
Does anyone know if storms actually do anything important to fish, or do they just scare the daylights out of them?

Same question for clouds. I always wondered if fish could equate clouds to 'more fresh water' to maybe prepare them for some makeup water/salinity changes, but we should be dribbling it in anyway.

Sun progressing I think does make sense - and if someone wants to do storms, more power to them (there's a lot we don't know about marine life), I was just wondering if there's a biological basis to this.

== John ==
 
Not sure how much sun progression over such a short distance really would help the life in the tank, but it looks cool for those taking care of them. I am sure storms and clouds would look real cool too. The more you enjoy watching them the more you will take care of them usually. That will help the life in the tank.

On the other hand a lunar cycle of moon lighting i do think actually can help the life in the tank by itself.
 
The common build for arduino I have seen here has 6 channels. So I was thinking 2 fixture with 6 channels or 3 fixtures with 4 channels. Not 12 controllers. If you keep the program pretty simple I would think you could run the same program in each and offset time a little east to west. Storms would be a bit of a problem.

Multiple channel sunrise/sunset. Looks cool, but let's be realistic. At sunset tonight go stand in your yard, now move 20 feet east or west. Is there a difference in the lights? Unless you are better than I am, the answer is NO. So this is a coolness feature only IMHO.

Storms, interesting question about the freshwater. I would think they are far enough down, the it would be mixed and not affect them much. An inch of fresh water after 20 feet of saltwater - I doubt it changes much. But then comes the issue if you don't have the thunder to with the lightning then forget it :)
 
These are all valid point guys and i totally agree with you.
I'm trying to do Amazon biotop and you will agree with me that in Amazon light is diffused through the leaves of the forest. I'm sure we all saw how in that type of environment light in the morning is very dim and progressively get's brighter as sun is getting higher. Also sun rays just don't show up at 12 o'clock but progressively get's there every second :) :). and with that sun rays travel in the water through the leaves from one side to the other where most of the day is completely lit by it with nice shimmer effect.
Your points are totally valid for reef aquarium.

I still haven't decided which driver to use for this. Since I need 1.5A of max current TeraHz's driver looks promising.
 
The CAT4101 can supply 1 amp, but you can run 2 in parallel to supply 1.5 amps.

It is not critical, but I am unclear and would like to understand.
I'm trying to do Amazon biotop and you will agree with me that in Amazon light is diffused through the leaves of the forest. I'm sure we all saw how in that type of environment light in the morning is very dim and progressively get's brighter as sun is getting higher.
Yep, I agree
Also sun rays just don't show up at 12 o'clock but progressively get's there every second .
Got this too, but I still don't see why you need 12 channel control
and with that sun rays travel in the water through the leaves from one side to the other where most of the day is completely lit by it with nice shimmer effect.
This is where I got lost
 
Actually, I do notice a huge difference between sunrise and sunset. Different plants are lit up and the light on the trees completly changes direction. :)

If the light truely changes angles, I think it'll be healthier for the coral also, so that all of their tissues get light. But a broad enough fixture probably does that too.

I'm actually finding the mechanics of this tough (Well, a lot of parts) and my front MH 250W ballast is about to go. Some mornings it won't start, and lately it's turning into every morning. I already lost one ballast that way - so I may need to scramble and just replace that fixture quickly. I have a bunch of RB and CW's comming from the [OMFG I might get banned if I list the web site], guess I need to speed up my DIY build right now.

I've found a couple of PWM Arduino shields that have plenty of outputs, but I also had an epiphany a while ago - a small Arduino can be cheap enough, instead of getting a big stack of shields, I could just sprinkle them around on each group of light fixtures, and then link them together through a CAN or I2C communication network. It's what the Apex seems to do. That might actually be better than running PH probe wires up into the canopy or a mess of control wires from the sump up into the canopy.

I do have access to a lot of PC 'brick' power supplies but they seem to be 19.5V. That is only 5 or could I eck out 6 LED's?

== John ==​
 
Just my thoughts:

If the light is coming in at all angle I don't think the coral will care if it is all directions at once or changes during the day.

Plants do change their leaves (I didn't think about that), but in order to really replicate the sun I think it would be too expensive. Not true of the sun but as an example assume every 10 degrees adds 10% more light. So you need 10% of your LEDs 10 degrees west, then 20% and 20 degrees, etc. Then you have to repeat for those facing east. So in the end you need 810% of the light. You also need a half circle over your plans. $$$$. Now you could aim 10% of your light at each direction, but then high noon is still a false representation of the sun.

Finally people have been lighting plants for years with just over head lights and they seem fine.

While I think it would look cool, I am not sure it is worth the time and cost.

Just my $0.02.
 
i agree with fisherman as well and I'm not planing to go to that extent but I would like to try to simulate that effect.
So, let me explain where 12 channels come from. In 60" tank with brace I would have 3 rows of 6 leds on the left of it and same thing on the right of the center brace. So sequence would go like this:
1. Warm white light comes slowly on. Dim from 0 - ~60%. Across whole 60" at the same time. Morning right. Like that until about 10:00.
2. Sun is already past horizon but It can't reach this body of water through trees etc.. but at 10:00 is high enough that has enough of angle to penetrate through trees and starts hitting our body of water.
So, very first row (now row is, if we face aquarium, straight in front of us. We have 12 rows of 3 leds that way) of COOL WHITE LEDs is coming on dim 0 - 60% and after that CW and WW are going all the way to 100% in the same row.
3. Somewhere in between first row sun coming up, second row should already start to come on and probably be at around 60% when first row is at 100%.
And like that in chain till the 12th row.
4. For sunset procedure should be reversed.

Guys, by all means I'm not advocating that this is necessary or this makes any difference or anything like that. I've had planted tanks successfully without all this jazz for almost 10years now but I personally think that it would be cool effect and as close as possible to the nature.
 
cool effect
Isn't that what I was saying. If you really want to do it go for it. I was not trying to come down on you; more make it clear to other that did not read everyhting that it is not needed.

By the way no pictures - we want time lapse video :)
 
lol.. "By the way no pictures - we want time lapse video" -- I'll try my best. It will take few months since currently waiting for my Achilles' tendon operation.. :(
No problem thefishman, I didn't take it that way at all..
 
Rather than a scads of drivers - unless they're DIY - you could use relays to re-direct the drivers outputs. So you might run half the drivers. Just make sure the drivers are off before a switch is made. If you do this with an Arduino that should be pretty easy.
 
I also expect there is an I2C chip with PWM outputs that might work.

I don't think you could use a relay since he want them all on at one time (0-60%). Which ever one is no selected would be either off or on. Or are you thinking of something else?
 
There would be a lot of 'blink' too but you could do it with a double set without that.

Say lights 1-n

2 ballasts

Turn on light 1 with ballast 1, ramp up brightness.
Turn on light 2 with ballast 2, ramp up brightness.
dim ballast 1, turn off
Turn on light 3 with ballast 1, ramp up brightness.
dim ballast 2, turn off
Turn on light 4 with Ballast 2, ramp up brightness.

Wash, Rinse, repeat.

(it would take 4 ballasts as you'd probably need a white / blue independant pair, but you get the idea).

I think that would be a 'bus' with a set of relays at each light, 'on' means you're connected to the bus. Well, 2 busses anyway (4 for the other color).

I like this idea. However, I had intended for all fixtures to be lit up at noon for max brightness then scaling back. I guess if these were parallel strings my bus idea could work, at noon you could just switch the off lights to one ballast. That one would have to have enough spare current to run all the strings in parallel.

I'd like to call it the "Gwinner Light Bar". :D

== John ==​
 
But he want all light to go from 0 - 60%. Then bank one goes 60 - 100%, then bank 2 60 - 100%, then bank 3 etc.

So I guess you would need a three way relay with the modes of ramp, 60% and 100%. As long as you only ramp one at a time you are OK.
 
I wouldn't leave them all on. If you do you will see little effect. The sun is a point source that moves across the sky casting shadows as its angle changes. If you leave on LEDs from all directions you will loose the entire effect of the shadow casting. It becomes a why bother dimming them at all.
 
I'm kind of lost here. I don't think I'm following you guys.
If I have two drivers per row (12 rows , 3 led's each facing front of aquarium) then one driver drives CW and one WW and I can program them whichever way I want, no?
Once we go opposite way where we start dimming off CW (sun) row 1 till 12 angle of light will change since it will not have 90degree leds on anymore and shadows will be different.
 
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