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Topic: need a way to run 14 RGBWA-Uv LEDs individually for a custom DJ light (Read 624 times) previous topic - next topic

Schradieck

To start, i'm fairly well versed in 120V electrical, but ICs and such are unfamiliar territory for me right now. (i do have some basic experience with Arduino)

A few years ago i got my hands on a vintage DJ Ufo style light, it was missing the halogen bulb and both motors were shot, as well as almost all of the lenses had lost their color.


It's been thrown around a lot as i tried to restore it fully, but now i've decided to change routes, and i want to rebuild it as a modern fixture.

I would like to first remove all the wiring and redo it for 12V and remove the color film from the last 2 lenses(which is easy enough)
Once that is done I'd put a (preferably) high power RGBW-A-UV LED behind EACH lens instead of using a single halogen bulb. This light fixture has 14 lenses so i'd need 14 LEDs

But i would like to control each LED separate from the others, as well as having full dimming/color mixing in order to make some intense effects, but i have absolutely no clue how to handle that,
From what i've seen Addressable LEDs are too dim for the scale i need.
I found a LED chip i like, But with 6 inputs (RGBWA-Uv) * 14 lenses gives me 84 separate signals.

I know i'm in a bit over my head, but this will be a fun project, i just need help.
i'm not as concerned about money at this time (although i will not just buy a "new" DJ ufo light)

I could really use suggestions on everything.
I am willing to settle for just RGBW chips, but i NEED them to be bright enough to create beam effects when paired with smoke effects (the glass lenses should help a lot here)


I would also like to put in something like stepper motors, and control them as well, but if it's too much to add them i can just use simple constant speed 12V motors

But right now i'm just concerned with figuring out the ideal light/controller combo, but i will try to detail the entire end planso you all can understand my thought process:
Firstly, the "Head" of this fixture is currently completely hollow, so i have some space to work with inside, but i would like to have the Arduino in the base of the machine and run a handful of wires up through 2 slip rings into some kind of decoder in the head that splits the input signal into the 84 separate wires that go to each LED chip. but i do think i might be able to fit the arduino in the head

As for the LED chip i want RGBW+Uv, but i couldn't find any that did not also have Amber, so that's what i'm going with (again, open for suggestions, i have not bought any parts yet)(i suppose i could just not connect the Amber to save 14 wires total) (maybe could use seperate RGBW and Uv chips?)

the motors i am not currently concerned with but ideally i would replace the 2 AC motors with some strong 12V steppers (maybe ones with an optical encoding for precise precision control)(i guess here would be the spot to point out this fixture has infinite rotation on both Axis, so i can't tell it to rotate until it stops to calibrate it)

For the software side i wanted to break it up into:
Rotation patterns,
Rotation pattern speed,
Color Patterns,
Color Pattern Speed,

ideally i would use a webpage or a DMX interface to control these settings so i don't need to do a full reprogram just to change a color theme for a holiday. but again. all i am concerned with now is the hardware side of things. i just thought explaining my plan could help.


sorry if this post seems scattered, i have a lot of troubles translating my thoughts into words so i need to type each thought as it happens,

SteveMann

What LED are you considering? I had never heard of a high power RGBW-A-UV LED until now, but there's about 50 of them on the Mouser website.  So pick one.

It appears that they are about $10 each, so buy a couple of extra units because you will likely smoke at least one of them in development.  Also note that 10-Watts is a lot of heat, so each LED would have to be on a heat sink, and preferably with a cooling fan.

(And ideas for next year's Halloween effects come to mind right away).

Controlling the intensity of the individual colors would not be big deal, but you would need to use a MOSFET transistor to control them with an Arduino. Study PWM control.  DMX and Web Interface is something I haven't done, but I know it's doable since others here have done both.  As a later project, you could make the lights color and intensity respond to music.

I suspect the motors are to make the light beams move?  Use mirrors.  An LED with heat sink would require pretty substantial servos.

Are you using this project to learn to program Arduino?  It's a bit aggressive, but not overly complex.  Get an Arduino starter kit and learn how to use the IDE and run the example sketches.

If you want someone to program this for you, then click on "Report to Moderator" and ask for the thread to be moved to "Gigs and Collaborations".

Schradieck

@SteveMann

mirrors are not an option with this body, so i will need motors that can move 30-40lb of steel and glass, but better to focus on JUST the led wiring for now, as that's where i know nothing. i do already have a large starter kit to practice with, and i'm not worried about the programming side of things, just the wiring right now.

I work as a DJ and i've been starting to make custom lights for my workplace, this will be the most complicated, but i also don't expect to be done this anytime soon, could take up to a couple years. during this time i'll most likely complete many smaller lights

as for heat i will use metal L brackets to wick the heat into the steel frame as well as a central cooling fan. this frame was meant to hold a halogen bulb that ran at 500°c, so it has a LOT of ventilation i can work with.

Music control and such are plans, once i have lights working. so better to think of this as a static fixture with 14 lights and nothing more

PaulRB

I would suggest to start with the basics. Get a Nano, a large breadboard or two, some 5mm common anode RGB LEDs, 5mm white LEDs, 5mm UV LEDs, connecting wire, resistors (e.g. 220R, 0.25W). This will be enough to get to grips with basic coding, pwm control and colour mixing.

You will quickly find that Nano only has 6 pwm pins/channels. Mega has more, but still far fewer than you need. Don't think of using multiple Arduinos, it's a bad plan. There are chips such as tlc5940 which you can use to provide more pwm channels, and you can chain many together, so only a small number of Arduino digital control pins are needed to drive all of them.

Another idea to explore would be to use ws2811 chips. You can buy strings of 5mm RGB LEDs with these chips already attached. Only one Arduino pin controls the entire string. It may be possible to buy the individual ws2811 sop8 chips and use these in your later design. Each chip has only 3 pwm channels, but they are small cheap chips. Unfortunately sop8 chips are not breadboard compatible for prototyping with, but you may be able to find some breakout pcbs to adapt them for breadboard use.

To control large LEDs which get hot, you must use constant-current drivers. The forward voltage of LEDs change as they heat and cool. The constant-current driver adjusts the voltage to the led to keep the current under control to keep the brightness consistent and prevent the led from burning out with too much current. So also start researching CC drivers. In particular, you want CC drivers that can be pwm controlled, and many don't have that feature.

Schradieck

Cool, thanks. I will look into all of those. I also had a realization, only the RGB pins need to be pwm controlled, all others can be pure digital, so I'd only need 42 pwm signals.

I do already have a nano, and I brought The fixture home from work so I can start slowly experimenting, current plan was to test a lot of loose LEDs with the lenses to get a grasp of brightness

Grumpy_Mike

I would suggest the PCA9685 chip as being better than the TLC5940, as it is a set and forget chip. The TLC5940 needs constantly feeding with pulses to keep it going where as the PCA9685 uses I2C and once you have set up the registers will keep on going with what you set it to.

You get 16 PWM channels in a chip and you can have up to 64 chips running on just two pins of the Arduino giving a maximum of 1040 PWM channels. You can get the chips mounted on a breakout board here:-
PCA9685
You can also drive servos with it as well.

Schradieck

Okay, for my own sanity i have tossed the idea of Uv, so currently looking at using 14 of each of these 2 LEDs (up for suggestions if you guys know of better super bright LEDs)

3-9W  RGB

1W White

RGB Leds + White LEDs, So only 4 Channels * 14 sections leaving me only needing 56 channels

But as far as i'm aware neither of those can work directly with a PWM chip due to their high mA, (350-750ma for the RGB)
I don't know if i need to look at moffsets, or if there is some pre assembled board that can step up the pwm signal to a higher amperage,

I am willing to pay the extra for pre assembled boards to help save some sanity once i'm dealing with 14 of everything, and there is quite a lot of space inside the lamp.



Also thank you to all of you for helping me with this, i really appreciate it


SteveMann

@SteveMann

mirrors are not an option with this body, so i will need motors that can move 30-40lb of steel and glass, but better to focus on JUST the led wiring for now, as that's where i know nothing. i do already have a large starter kit to practice with, and i'm not worried about the programming side of things, just the wiring right now.
It's hard for me to visualize 40 pounds of steel and glass.  Times 14 LEDs = 560 pounds.  A quarter of a ton?

I am imagining a mirror with elevation and azimuth servos and the LED source fixed- immovable- pointing at the mirror.  Times 14, you may hit 20 pounds on the scale.

Schradieck

It's hard for me to visualize 40 pounds of steel and glass.  Times 14 LEDs = 560 pounds.  A quarter of a ton?

I am imagining a mirror with elevation and azimuth servos and the LED source fixed- immovable- pointing at the mirror.  Times 14, you may hit 20 pounds on the scale.
NONONO, not at all like that, it's a single 2' diameter disk with 14 glass lenses around the edge, the TOTAL weight is about 40Lb. If you could not see the picture i linked with the first post it is supposed to have a single halogen bulb that sits in the center and shines out 14 colored glass lenses that rotate slowly around the bulb. (lenses have lost their color and are now clear)

My plan is to instead put an LED behind each lens to give me a lot more control, Each LED will only be about 3" from the last, arranged in an outward facing circle

If my linked image in the first post failed google image "Lampo Astro 2" to see exactly what it is,

PaulRB

Have you considered these AdaFruit Pixie leds? I only just learned about them myself. I am a bit concerned that they don't use constant current drivers. Apparently they reduce their own brightness if their temperature gets too hot. That situation may be possible to avoid with your extra heatsinks & fan cooling.

Schradieck

Okay, so i have decided to go with those pixies, (rip white) but now i'm trying to figure out power, if i have this right:
24V 10A power supply in the base of the unit, feeding up through a slip ring to the head
(slip ring restricts wire size i can use, exact slip ring not picked out yet)

inside the head have the 24V feed two
5V Buck Converters that'll give me a max of 30A each, and have each of those power 7 LEDs chained together with 10AWG wire.

now for the part that confuses me, for the ground wire that goes back to the arduino, do i bridge it between the 2 sections of lights, or run the second wire alongside and tie it to where the ground comes off of the first section (basically a Y connection)


not this threads topic, but maybe i should size the psu to also handle the twin stepper motors?

PaulRB

It may he important to avoid too much current flowing through the PCB tracks on the Pixies, both 5V and ground. So consider 5V and ground wires from both ends of each group of 7 LEDs going back to their respective buck converters. Also a smaller ground wire running parallel with the data wire back to the Arduino.

Schradieck

Somehow tired sleep deprived me realized mid-day me can't do math.

When I was doing psu sizing I forgot to /V, so for some reason I wrote down in my notes that I needed 42A, when that was my wattage. I only need 8.4A, so I need to redo my PSU plan in the morning

Will get a good 12V one though, to make sure I can run the steppers when the time comes

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