This is a very inexpensive (less than $3.00) , nice looking, and fairly easy to make night light.

I have been working on another project for my four year old daughter. That instructable will eventually..... be out as it is over 100 man hours already and not even close to done. Anyway a couple things (some glass tiles and some LED's) that I got for that project didn't work out. One night sitting at my desk I was fiddling with the LED's and noticed the glass tiles and liked the light. I kinda side lined the project because the LED's required a 12V power source and any other 12V power sources I had other plans for or were in use for something else. Then Comcast decided to upgrade our cable modem and one of the options for the used equipment was to turn it in to a recycling facility. Well... I AM a recycling facility lately LOL noticing the cable modem had a 12V wall wart it was time to get this project banged out.

I have to say that the pictures really do not do this justice. It is hard to take a good pic of it since cycles through colors and obviously flash would not do it justice. I may try to upload a video of it at some point.

Step 1: The LED's

Just a note about these LED's. I picked them up from Ebay for $.99 with free shipping and it included 10 (for the love of all that's holy how do they manage this???). The description and pictures weren't that great just said something like "10mm 12V RGB Rainbow LED's Pre-Wired" so for $.99 how in could I go wrong right? A 10mm LED is not generally what I would want, but for the project I got them for they would work IF I could manage to "un-wire" them and control the RGB with an MCU. Since the pictures didn't really do a good job of displaying the item I hoped that maybe they were RGB LED's with some sort of little IC that controlled them or that they were 3 LED's wired together or something else that I could use or abuse. Unfortunately when I got them and pulled one apart the only "pre-wired" part was a resistor soldered to one pin, the actual wire. Turns out there is an IC in the LED itself that cycles it through the colors.

I mention all this because for this project that LED type is absolutely perfect and I would suggest for this specific project to find some of these if you can. If you cannot find this sort of LED there are other options like

1) You want to have the night light be a single color and just wire in some LED's that way (I don't suggest this as it would be kinda plain and doesn't really show off all the color that can be seen)

2) You want to get normal RGB LED's and build your own controller for cycling through. If you want to do this there are a bunch of instructables for various ways to achieve this and you should search those out. As an example here is one using Arduino (though would be pretty easy to just program an AVR instead). How to Use an RGB LED I would also imagine you could use some 555's and logic level mosfets to accomplish the same anyway LOTS of potential options here.

3) You could salvage something from another item like this instructable RGB LED Color Cycling Circuit

4) Use some "El Wire" (Electroluminescent wire) lots of instrucables about this. I haven't used this stuff before and not sure if it is bright enough but suspect it would work fine.

These alternative options depending on which you chose could have the following benifits.

1) Lower power consumption

2) Smaller size (more lights in there or more options for cycling)

3) Possibility of controlling the lights via interface (computer, knobs etc...)

Step 2: Tools

The tools you will need for this are:

A Dremel or other rotary tool with a diamond cutting wheel. (This is not strickly necessary if you can stack your blocks in such a way that you don't need to cut the tile but I did need to.)
Glue gun
Soldering iron
Straight edge
Box cutter or X-acto knife
Solder sucker or solder wick (only if you need to get the power plug from some other device you may not need this)
Multimeter

Step 3: Materials

The materials you will need to do this are

Small PCB prototype board or perf board
Electrical tape (or heat shrink tubing)
Solder
Flux (optional though advised)
Some clear plexiglass
LED's (See LED section for more details)
Wall wart (my LED's required 12V yours may be different you will need to check your needs to match)
A switch
Glass tile
Plastic dots (for the feet to sit on)

The glass tile that I have came from Micheals which is a large hobby store. Got about 30 of the tiles for about $3.00 so nice and cheap. I did however take a trip to Home Depot the other day and saw a HUGE selection of sample packs they have available. Some even have stone or metal that come in the packs so options are large here. The Home Depot packs were considerably more though ($12-$20).

The switch I used came from an old PSU that was dead. It is a simple 2 pin rocker style switch. I picked it because it fit perfectly into the channel. You could use some other style of switch if you like.

I got the plexiglass (acrylic) from a cheap dollar store picture frame. I had some scrap of it left from another project. This is used for the first course of tiles to be the base. You could use something else (if something else probably something reflective) as the base plate. I used the plexi so that the light could shine through.

I got the wall wart and female receptacle plug for it from a scrapped cable modem. You could buy one, recycle one from some old appliance or whatever.

Step 4: Preparing

Get all your pieces together.

The first thing I did was get the power receptacle off the board. I had to dremel it off. Simply desoldering it didn't allow me to get the legs off (without damaging it) so I VERY CAREFULLY cut out the receptacle and cut away the PCB from the pins. I have a real habit of being heavy handed with such things and believe me it's very easy to snap the legs off or crush the plastic housing with pliers and that simply wont do so gentle and slow.

The next thing you want to do is to stack your tiles up. You want to do this for 2 reasons. First you want to see how you want to mix the colors. Second you want to make sure that you have room to fit your LED's, their wires, the perboard, the switch, and the power receptacle.

As you can see I stacked mine in a simple rectangle and I liked that but you could certainly get creative and have tiles sticking out, do a pattern like a star or any number of things. You might also want to make a stand, embed the tiles in some other enclosure lots and lots of options here so take the time to construct it before committing.

Step 5: Start Building the Tile Housing

Ok now that you have stacked your tiles and know what your base is going to be we want to cut out a piece of plexi slightly smaller than the outer edges of the tiles. (as mentioned earlier it doesn't have to be plexi it could be metal or some other material just something as a base I liked the plexi so the light can go out the bottom too)

Put your tiles on the plexi and mark the outline.

Get a straight edge and score the plexi. Now snap it by being firm but not brutish. If it doesn't snap score it a little bit deeper and try again. We don't want it to crack off our line.

Now we break out the glue gun. I suggest doing this on a flat surface and paying close attention to how level your tiles are going on. The tiles are not completely smooth or flat on any surface, the glue can make one side higher than another if you don't pay attention and when you get to higher courses this can be a problem. This isn't something that has to be "exact" by any means just roughly level.

Place some glue down, place a tile, let cool, glue the edge and base for the next repeat until your bottom base is complete. Start the next course and continue until you get to the point where you will be placing tiles across the top and closing it in. We need to be able to put the LED's and lights in there so we leave a channel until we have that done.

As I mentioned earlier I actually had to cut some pieces of tile with my dremel diamond wheel on the back edges so that the I could leave some room for the power receptacle and the switch. You may have stacked them in a way that doesn't require this regardless factor that in when putting it together. I marked them in the photo above so you can see what I mean.

At this point you should have something like the last image that has the channel labeled on it.

Step 6: The Circuit

The first thing I did was to check the actual output of the wall wart with my multimeter. I am glad I did this since the actual voltage coming to the receptacle was 14V not 12V 1A as written on it. Now if I actually knew what the forward voltage and amps were for these LED's some simple math would have been easy. Unfortunately for me the cheap price came with the consequence of no documentation and as such I had to wing it and test a little and cross my fingers that I didn't blow my LED's. So... since I was going to be using 4 LED's I wired them up in series, crossed fingers and hoped that the resistor values were enough to drop the voltage (yes I did actually cut one open to see what resistor value it was but in cutting it the colors were to hard to make out on the really small resistor being impatient and well this was a side project and I had 10 LED's after all right :) )

So.. the finger crossing worked. Too well in fact. In series there wasn't enough voltage to light them up and so I knew I had dropped below the necessary 12V and as such did a combination of series and parallel wiring. Viola! a 2 series in parallel was perfect. I left them running for a good while checking heat and making sure they hadn't blown and sure enough all seems in order.

Time to solder it all up.

First cut your proto board to size

Cut holes in your proto board to accommodate the legs of the power receptacle and solder the receptacle to the board.

Solder your switch positive to receptacle positive and negative to negative.

If you have pre-wired LED's like I did you will want to trim the wires down a good deal so they aren't clogging up the space and blocking light inside the cube.

***Please note the below applies to the specific way I have to wire these if you have different LED's and/or power source you need to wire it accordingly. This is a good tool to help you wiring LED's LED Array Calculator

Wire your LED's together this way. (again ONLY IF you are doing EXACTLY what I have please check your LED power requirements and check your power supply with a multimeter to make sure). Unfortunately most of these pictures came after I had things wired up and done so I taped some together and took a pic so you could see what I meant. I obviously didn't wire them together as it was just to show the connections not actually wire it.

First take two and wire them positive to positive.
Take the other two and wire them negative to negative
Now take the negative from one pair and wire to the positive on the other pair. Tape this one up as it is not going to be wired onto the board.
Repeat step 3

Ok now wire positive to the positive of the switch and negative to the negative of the switch. Yes caps, might be a good idea, a diode might not hurt either. This was quick cheap and easy though and for the under $3.00 I am not to worried about it dying.

Test your lights. If it's working well on to the next step.

Step 7: Finishing Up

Now that we have our circuit up and running and working time to finish up. Place your board into the cavity we created earlier. Pay special attention to the placement of the LED's. The ones I got were a bit odd with their viewing angle and they created a halo effect at a distance and didn't emit much light directly above the LED or on the lower band. I suggest that you put them in and position them pointing in different directions to get the most light distribution. To do this put them in then stack but don't yet glue in your remaining tiles. Get them how you like them and then glue in your circuit board. Check them again and then start closing it up and seating and gluing in your switch. See the photos to see how I have mine though again you could place the switch differently or use a different style of switch.

Finally put on some plastic feet on it to keep it from sliding around and to keep it from being roughed up. It helps let light out the bottom too.

I left a little room open in the back as you can see. I could have closed that up but opted against it if I ever wanted to access the inside again it would be easier. Your choice.

Hope you enjoyed it and hopefully you will make one yourself.