This is the first part of my Pimp My Balcony (PMB) project.
I decided a while ago to clean up my balcony and make it as cozy and an awesome spot as possible using mostly old unusable rebuilt stuff.

What you'll need for this instructable are:

-Balls (Free if found)
-Dremel or some kind of drill (Free, if you don't have a drill or dremel, be creative)
-Wires (free)
-Slow flashing RGB LED ($0.99 for 20 pack at ebay)
-100 ohm resistor (scavenge this or buy for 100pcs for $0.79 at ebay) (any resitor between 82 and 150 ohm should do)
-Soldering equipment (Should already have one. Every DIY-person should have one)

Links:

LED

http://www.ebay.com/itm/20pcs-5mm-Diffused-RGB-Rai...

Resistor

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p...

Total cost for me was $0.99 for the LED's since I had the rest of the stuff and I've got some in spare now so I was pleased :-)

lets get going then!

Step 1: Getting Some Balls

I found this old music player in the recycling bin one day and took it home to scavenge some parts from it. I managed to get some good potentiometers, connectors, leds, push-buttons and speakers that are being used in other projects. After all that, I was left with the empty shell you see above.
One day I realized the balls would make some great mood light so I scavenged those too.

The wires where scavenged from an old psu that I rebuilt to use as a bench-top power supply. I sorted out wires in matching colours to be able to use for this little project.

Step 2: Prep Work

Small 5mm LED's are usually made to focus the light, acting like a spotlight which is not really what we want for this project. A good idea is to use already diffused LED's when doing this project but since I only had clear LED's at hand and didn't want to order new ones, I decided to diffuse them myself.

This can easily be done by grinding down the top a bit and grinding the sides to diffuse it. You can see the difference in on the pictures between diffused and non diffused LEDs

Step 3: Making the Strip

I took me a while to realize how I would get the LED's in the balls in a good way making them face into the ball. After a lot of tinkering I came up with a stable solution that worked quite well.

I drilled small holes on the sides of the balls where I threaded the wires in and then soldered them on to the small PCB parts.

For the PCB I used small pieces of an experiment board that I soldered all the parts (led, resistor and wire) on. Since the led require what I'm guessing ~3V 20mA and my plan was to use 5V input. And a quick calculation with ohms law showed that a 100ohm resistor would do the trick. So I connected all the LEDs in parallel. This is not only necessary (since connecting in series would require more than 5V to operate) but also gives the advantage of that if one led happens to malfunction the others would still work.

Just solder all the parts as seen on the drawing.

Tips:

To make this a bit more durable I tied a knot at the end of each wire. That way in case of any strains the knot would take the load instead of the soldering which will make it last a lot longer.

And I also used three lanes just to avoid any unwanted bridging due to bad soldering or what ever but you could use two lanes if you want.

The wires from a psu are a bit over dimensioned for a project like this which means the wires are quite thick. It made it a bit trickier to solder it on the pcb but trimming it down a bit really made it easier to solder on.

Step 4: Connection and Switch

For a switch I had an old battery holder with built in switch that was perfect for this. I de-soldered the wires on the battery holder and soldered on the negative wire from my strip to the switch. (The red wire just goes right through)

And the reason I was set on using 5V was that I wanted to use a USB connection to power this so I found an old USB to USB mini cable I was sure I wasn't going to use for anything and cut of the mini part and soldered on the red and black wire to the respective counterparts from the strip. The white and green signal cable can be cut of and sealed with electrical tape or shrink-tube to prevent any shorts.

Finally seal everything with shrink tube and you should be done. A good practice is to test everything with a multimeter to make sure you don't have any short somewhere after that just hook it up to an available USB port and you should be amazed by the dazzling effects of changing colours.

According to my calculations these light should draw around 3V 20mA since they seem to be pwm switching from one led to another there are never more than one led lit at a time. And since I've got nine of them in parallel it should add up to 180mA which is totally safe to run on a USB port. (At worst cas two leds are lit at the same time resulting in 40mA of current being drawn which would add up to 360mA which even though it's unlikely still safe to use)