garden light retrofit

[justDIY]

Tired of my neighbors blue-white garden lights, I set out to make my own, better, brigther and more complex

i plan to setup 8 or 10 so lights similar to this, all daisey chained off the controller

my rgb led controller allows custom programming of color palettes, as well as a variety of fader and random options

none of the "in action" pictures or videos I took at 1-2am last night came out very good (gee i wonder why), so I'll be back again tonight with a tripod and steadier hand to get some money shots to share.

I need to find a better diffuser as well, somehow I don't think tissue paper will last very long outdoors, and it's certainly blocking more light than it's passing



RGB led controller, strapped to a battery pack



RGB led module front side



RGB led module, messy solder side



Module mounted inside light fixture



Another angle of the mounted module

[Rob]

For a diffuser, I like acrylic sheet sanded to a matte finish (use 400 grit or thereabouts). I've got one other light dispersion trick up my sleeve that would probably interest you though, stay tuned.

[justDIY]

ok, another picture and a short video

my camera does not like the dark at all... the video doesn't do the lights (only 1 pictured) justice, human eye is much more sensitive to dim settings than my $$$$ digital camera

the video shows the light jumping through some of its programmed color palette... in real-time, it takes about 15 min to fade from one color to the next (adjustable), but heck, who wants to watch a video of that

oh to add;  I stopped using tissue paper, or any sort of additional diffusor except for sanding the led lenses (they were 'water clear') and the diffusion provided by the light fixture itself.  It seems to look pretty good shining on the ground, but if you look directly at the fixture, you can see the individual colors coming from the led

I wonder if I sheared the lense completely off the led, if that would help or hurt diffusion

*****

some more details about the controller:

palette of 20 customized color memories
sequencial or random fader 'playback' of the palette
randomly generated color fader
fully adjustable fader delay and fader duration

currently powered by 5 volts, using cat5 cable to daisy chain the lights (using each pair as a single wire), working on new pcb that supports 12volts, although voltage drop isn't as bad as I thought it would be... at the end of ~20 feet of cat 5, I read 4.9 volts off my regulated 5 volt psu

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here is the garden light doing its best "bluish white" impersonation


video clip of garden light quickly jumping through preset colors (5.2 meg, quicktime)
http://www.manisteecomputers.com/video/garden-light(short_clip).mov

*****

more pictures to come

[Rob]

That purple is pretty striking.

[Elmo]

Hi,

Just browsing the internet to find onfo about RGB leds. I'm trying to make an RGB led pannel for in my livingroom. Will put an photo in front of it and adjust the backlight to fit the photo. I have the pannel (108 leds) - 3x 36 grouped by 4) and can andjust the color manualy now by using adjustable resistsors.

As of an answer to your open question about the diffusion, I use an milkwhite plastic cap, like a half pingpong ball but then of the special perspex used to put in front of the advertising signs. This diffuses the light for the first time and then the outer cover will do the rest ( the distance of th efinal cover is important to the brightness)


Now looking for an more automated methode of setting the color, using a PIC. Just starting to learn to program them.

Is there a way that i can get the code of the pic? Looking at your photo the schematic isn't that hard to make.


Kind regards,

Peter

[justDIY]

interesting tip about the ping pong balls ... I'll have to try that!

I also considered drilling an inverted cone into the leds, to make them into side emitting rather than directional - just haven't gotten around to it.

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the circuit is pretty simple... the code is where all the magic is

I can give you some example code of doing pseudo-pwm in the PIC ... the only language I know is Proton Basic (now called proton development suite).  There are also more examples at www.picbasic.org/forum

the pwm itself is pretty simple, there is a native command in basic, called PWM, that will generate a pseudo-pwm pulsetrain on any output pin. 

PWM Pin, DutyCycle

I say pseudo-pwm since the output is not clean and controlled, it needs a bit of finese to get a clean square wave... the frequency also changes dependent on the duty cycle.  You're also limited in bandwidth due to the weird way the pulsetrain is generated.  You have about 128 "brightness" values on each output, so, you can still mix ~2 million shades.  the latest version of my controller (a product i'm developing commerically) uses a totally different method (and circuit board), generating 1024 brightness values per channel, that's over 1 billion shades.

PS

Welcome to the boards!

[Elmo]

The sample code would be great, I'm learning C, so i'm not sure if i can read it.
Will give the protonbasic a try, to see what it can.

About the schematics, i'm investigating the MAX6964 chip. It has 9 RGB channels controlled by an MCU.
I have an (40cm x 40cm) ledboard with 3 x 3 prints with each 4 sets of Leds ( 1Red, 1Blue, 1Green). This makes up 108 leds in total. I can control the print using 3 transistors that will fire the 4 sets of RGB at once. ( will make a photo and post it later on).
So if i can make a print using the PIC and the MAX6964 chip i can control each print on its own.
The ledboard i use is from Skytronics, the board is about $50. The leds on it are from good quality but the circuit is not.

The only challange now is the code for the PIC, this is something i'm tring to learn. Will try the forum you mentioned.Can you drop me an email with same sample code for the PWM ( i;m gessing that PWM is Pulse Wide Modulation, read about is when i type RGB and PIC, but have not yet an idea what it realy means.


Thanks.

[dleiman]

justDIY, I have found very interesting things you have developed.
It seems you know what you're talking about.

How can we get the Schematic and Code for RGB Fading, to do something similar as Garden Light?

Thanks,
 

[justDIY]

justDIY, I have found very interesting things you have developed.
It seems you know what you're talking about.

How can we get the Schematic and Code for RGB Fading, to do something similar as Garden Light?

Thanks,
 

Hi dleiman, and welcome to the boards.

I'd be happy to share the schematic with you - it is pretty simple ... just take a PIC microcontroller and connect a few outputs to transistors (I used FET but any type should would work), in this case three outputs were used, connected to three transistors, one for each of the discrete colors.

the basic code for driving the LEDs (rgb or otherwise) is based on code I found at www.picbasic.org/forum - search for RGB led and you'll see lots of code on it.  the random and sequential fading code is something I cannot share right now.   I can give you some hints - the random code involves lots and lots of mathmatics ... a much simpler approach could be to use a desktop PC to generate N number (10, 100, 500, etc) of color cooridinates, and store those in an eeprom, and then your microcontroller just needs to do simple lookups instead of recomputing all the numbers

[Elmo]

A little bit late but here is the picture of the RGB print i was talking about.

It contains 4 RGB Caps, under the caps (sort of ping pong balls) are the 3 led (R, G , B).

[jlforester]

Your project is very similar to one I've been working on for a little while now.  I'm putting together some addressable color changing landscape lights.  The way it works is llike this:  There is a central conroller that provides power and control for the individual landscape lights.  There are 4 wires: 2 power (15V), and 2 data (RS485).  The controller sends commands in packets on the data lines, and if a light sees that the command is addressed to it, will respond to the command.  Some examples of the commands include: SET_COLOR, FADETO_COLOR, MEM_SET_COLOR, etc.  Each light has 16 non volatile "color memories" that can hold a single color.  The system controller is driven by a PIC 18F452, has an LCD for display, and a keypad for navigating the menus.  I'm programming several types of light shows into it along with some "static" effects (alternating red and green for Christmas, for example).  Some of the active light shows include a color ramp, a twinkle effect (a random light is briefly set to white before setting it to a random color), and a waterfall effect.  I put a clock chip on the controller so that I can set it up to turn on and off at a programmable time.

The landscape lights have two PCBs.  One contains the driver circuit which uses a PIC 16F628A.  The other PCB contains 9 high-brightness LEDs (3 each red, green, and blue).  I'm mostly working on the software at the moment, but am tweaking the hardware a little bit too.  I'm redoing the layout of the LED driver PCB and will probably order some new boards soon.  I hope to have 25 of them up by the end of summer this year.  I've got some pictures and videos of the prototypes in action.  I'll post them on my website once I get the website up and running.

[Rob]

Good stuff, jlforester. Welcome to the boards.

[jlforester]

I put some movies of the project in action up on my gallery.  It's located http://www.wvishome.com/jack/pg.  Everything is located in the "Color-Changing landscape lights" album.  I'll add some photos later.  Please enjoy!

[jlforester]

I've finally got more of my website up so I've started describing my LED landscape lighting project in more detail there.  Please feel free to leave comments in the gallery.  It's the only part of the site where I currently have the ability to allow users to leave comments.  I promise not to give away any information you enter when registering (you have to be registered to leave comments)...I hate spam too.

Oh, the url:  http://www.wvishome.com/jack

Sorry to have apparently commandeered this thread...but my project is a garden light retrofit too!