This Bluetooth Controlled Rainbow Lamp can be switched to any color by using your smartphone. The lamp not only looks like all the seven colors of the rainbow but also glows in all the seven colors of rainbow. The shapes that it makes at night are just amazing to watch. The design of this lamp may seem complicated, but you will be surprised to know that it is made by just cardboard, nothing else! Actually the original design was taken from crafts thrift . I made little modifications in the design.You can reuse your old cardboard boxes to bring them back to life by making it instead of throwing them away. Since it uses old cardboard which is reused to make it, that makes it recycled. You can use it as a night-lamp or for decorations in certain events. It can be hung on the ceiling with the help of the string or can be simply kept on a table.

The electronics of the lamp that makes it glow in different colors comprise of an arduino that acts as the brain of the lamp, bluetooth module that receives signals from the smartphone and RGB leds that gives out light of different colors. When you touch your phone to produce a certain color, the smartphone sends a command which is received by the bluetooth module. The module then transmits that data to arduino which processes it and makes the led glow in certain brightness. The brightness of each color of the led can be controlled as they are connected to the PWM pins of arduino. If all this seems complicated, just calm down and skip all this.

If you don't have experience in electronics and have never tried any project with arduino, you can make a simple lamp with a light-bulb attached instead of leds. That would skip a few steps of this instructable and would lower your work. But on the other hand, you will lose the main feature of this lamp i.e.- to select a color wirelessly through your smartphone.

Here is a video of the project in action:

So here we start with making this project .If you have doubt related to this instructable or found an error, feel free to comment, ask a question or correct an error.

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Step 1: Parts and Tools

The following parts, tools and materials are required to make this project. You can skip the electronic parts and tools if you want to make a simple lamp with a bulb. The total cost of the project was around $35 or 2100 INR including the electronics and $5 or 300 INR excluding the electronics. All the electronics can be easily bought from your hobby stores or over the internet.

PARTS:

• 1x Arduino uno (Ebay Link)
• 1x Bluetooth module (HC-05) or other (Ebay Link)

• 4x RGB LEDs (Ebay Link)

• 1x 9v Battery
• 4x 100 ohm resistor
• 1x 9v Battery clip
• Female-Male jumper wires (Ebay Link)
• Rainbow cable
• Perfboard

MATERIALS:

• An old cardboard box or a sheet of plain cardboard
• Paper adhesive
• Paper Cutter
• A pair of scissors
• A marker
• A ruler
• Tape
• A paintbrush
• Acrylic or poster colors

TOOLS (Optional):

• Soldering Iron
• Soldering Wire
• Wire Cutter/Stripper
• Hot glue gun w/glue sticks
• Pliers

Step 2: Mark the Cardboard

The first step to make this lamp is to mark the strips on the cardboard. Mark using a ruler and a marker, seven strips each one measuring approx three centimeters of width and 50-60 centimeters of length. The length and width can vary according to your choice of the size of lamp. Make sure that the strips are not too big or too small. That would lower the looks of the lamp.

Step 3: Cut the Strips

Using a paper cutter, cut a total of seven strips which were marked with a ruler earlier. You can also use scissors to cut them but it would distort their shape if not cut properly. Beware of the sharp blades of the paper cutter. They can slice your fingers. Take help from an adult if you have not done it before.

Step 4: Cover the Strips

For easy painting of the lamp with paints, I chose to cover them with white paper. So cut some white chart papers having a size a little larger than the strips. Stick them to the strips using paper adhesive. You can even use colored papers of all seven colors instead to skip the task of painting them.

Step 5: Make Pentagons

After covering all the strips, you need to make pentagons from them which will make the main body of the lamp. For this, first check the length of a strip then divide it by 5. For eg. if the length is 60 centimeters, divide it by 5 and you'll get 12 centimeters. Now mark your strip using a marker leaving a distance of the quotient. You will get a total of 4 marks. Now fold the strips at each mark. Stick the two edges of the strip together to make a pentagon. Each side of pentagon should be equal to the quotient obtained earlier.

Step 6: Stick the Pentagons

Stick all the pentagons one above the other. Make sure that the edge of one pentagon should be in the middle part of the side of other pentagon. Do the same for all other and stick them alternately. Refer to the image above for instructions.

Step 7: Color the Lamp

The next step is to color the lamp with all seven colors of the rainbow. You don't need to buy all the seven colors but you just need- red, yellow and green. You can make the rest four colors mixing the above colors in a certain ratio. Color the lamp in the order- VIBGYOR from bottom to top. Refer the instructions below to make all the colors by mixing.

Violet = Red + Blue
Sky Blue = Blue + White
Green = Blue + Yellow
Orange = Red + Yellow

Step 8: Connect the Bluetooth Module to Arduino

So here we start by connecting all the electronics. The next few steps are optional if you want to add a light bulb instead of making an rgb lamp. The first step is to wire the electronics is to connect the BT module to arduino. Use male-female jumper wires for this. Refer to the text below for connecting it.

Vcc ---- Arduino 3.3v or 5v (according to your module)
Gnd ---- Arduino gnd
Rx ---- Arduino Tx
Tx ---- Arduino Rx

Step 9: Connect the RGB LEDs to Arduino

This is the second step to wire the electronics. I used four 5mm rgb LEDs to light up the lamp as only one would look too dim. For identifying the leads, use a 3v button cell or look at the length of all the leads. I connected the LEDs in parallel as it would not work in series.

Solder all the LEDs on a piece of perfboard and connect them in parallel. Refer to the schematic above for reference or look at the text below for instructions. Connect them to arduino by soldering female headers on perfboard and using male-male jumper wires.

Gnd ---- Arduino gnd
Red ---- Arduino digital pin 3 (PWM)
Green ---- Arduino digital pin 5 (PWM)
Blue ---- Arduino digital pin 6 (PWM)

Step 10: Add a Cover to the Lamp

After wiring all the electronics, make a back cover by cutting the cardboard of the size exactly the same as the top of the lamp. Paint the cover with any color then stick all the electronics above it using double sided tape. Stick the rgb LEDs inside the lamp and pass the wires by making a hole on the cover.

If you are making a simple lamp with a lightbulb, just simply pass the bulb through the cover reaching inside the lamp with the holder remaining above the lamp.

Step 11: Power the Lamp

For powering the lamp, you can use a 9v battery for making it portable. Another solution is to connect the arduino with a USB cable to a USB charger or a laptop.

If you have a lightbulb, you need to power it with your local ac mains supply.

Step 12: Upload the Code

Upload the code given below to your arduino by downloading the ino file below and adding it to your arduino folder in documents. Make sure that before uploading, you remove the RX and TX wires from the Bluetooth module. If you don't, you will get an uploading error.

Original code source: http://microcontrollerkits.blogspot.in/2013/06/arduino-control-rgb-led-via-serial-port.html

RGB_LED.ino
Download

Step 13: Install the App

The last step is to install the app that will send signals to the lamp to switch the colors of the lamp. Go to the link given below to install the app.

For connecting and operating, refer to the instructions given below.

First switch on the lamp so that the BT module is activated.
Through your smartphone, pair your module to it.
Open the app. Click on the icon asking you to connect to the module.
Connect to your phone to your module.
For checking, first swipe the red led controller. If the lamps glows red, that means it works.
You can make any color by mixing red, green and blue on certain brightness.
Select the 'blink' icon to blink the lamp on the color selected. Adjust the speed by selecting the + and - icons.
Select the 'fade' icon to fade your lamp in different colors. Adjust the speed by selecting the + and - icons.

Step 14: You're Done!

So, you're finally done making your own recycled rainbow lamp. Enjoy all the glowing bright and beautiful colors changing slowly. Select any color by mixing red, green and blue. Use is as a nightlamp or for Christmas decoration. You can hang it using a string or simply keep it on your table.

With this, that's the end of this instructable. Hope you liked it. Please vote for me in the contest if you think this deserves a win. Feel free to comment or ask any question and do post your pictures if you have made one yourself or modified it.

Thanks for watching :)

Introduction: Bluetooth Controlled Rainbow Lamp