The Coloring Lamp is a device that is meant to allow users to explore additive color theory, which is mixing colors utilizing red, green and blue (the primary colors of light). By mixing different intensity of red, green, and blue lights, the user can create multiple combinations of a variety of colors.
Red + Green = Yellow
Red + Blue = Magenta
Green + Blue = Cyan
Through the use of bend sensors, the user is able to change the intensity of each color. This instructable will teach you to make these bend sensors, the complete circuit for connecting the red, green, and blue LEDs and how to connect it to the arduino.
Red, Green, and Blue LEDs
Wire Stripper and cutter
Hot glue gun and glue
Paper (thicker than regular printing paper would be advised)
Bare Conductive Paint
10k and 220 Ohm resistors
Solder + soldering iron
Scissors, tape, and ruler
Step 1: Bend Sensors
Since we have a red, green, and blue LED, we will need three bend sensors to control each one individually. The circuit should be the following:
GND -> Copper Tape -> Conductive Paint -> Copper Tape -> 10k ohm resistor -> same side of the resistor to Analog pin in the arduino (A0, A1, A2) and the opposite end of the resistor to POW
Construct it on a piece of paper where the bend sensor occupies half of the paper (we will use the other half to construct the circuit for the LEDs) and any breaks between the copper tape need to be soldered. If the conductive paint to the copper tape, then paint over again with more paint until there are no cracks.
Step 2: Making Circuits for LEDs
The next step is to make the circuit connecting the LEDs. Create a stand for each LED by folding a thin and short piece of paper in half. Use copper tape to make one side for GND and one side for POW. Solder the LED to the thin paper stand and then attached the LED stand to the other half of the piece of paper with the bend sensor.
Create a circuit where the negative side of the LED goes to GND and the positive side goes to a 220 ohm resistor and from the resistor to a digital pin. I used digital pins 11, 10, and 9 because we need the LEDs to have a variance in its intensity therefore we need PWM pins.
Step 3: The Stand
Next step is to make the stand. I used thin wooden sticks to create a frame and legs as the stand. I used hot glue to build the frame. Then I hot glued paper onto all of the sides except the bottom to give it uniformity. The paper on the top face of the frame needs holes for the wires to connect the LEDs and bend sensor to the Arduino.
Attach the bend sensors and LEDs by putting the wires through the hole.
I used red wires to connect all of the parts of the circuit that needed POW and black wires to connect GND. Blue was used to connect the bend sensors to the analog pins.
Solder all of the wires to the circuit. For POW and GND, I made a common copper tape strand that was connected to the POW and GND from the arduino so that any component that required POW and GND just needed to be connected directly to those strands of copper tape respectively.
Step 4: Code
Next step is to upload the code. If you used Analog pins A0, A1, and A2 as well as digital pins 11, 10, and 9, then you can just upload the code directly as is below.
Once all of the connections have been soldered and connected to the arduino and the code is uploaded as well, tape the arduino inside of the stand. I taped my on the top face piece of paper inside.
I used a 9V external battery to power my arudino and so I cut a little hole on one of the side faces of the stand so the external battery could go through.
Step 5: Diffuse the Light
Important step in directing the LED lights to hit the same spot by creating a cover to diffuse the light and direct it. Since we soldered and hot glued the LED stands to the bend sensors. We haven't tested to see if they hit the same spot, but since we oriented them all facing in the same direction and made them about equal height, if you move the stand far enough then the LEDs should hit the same spot.
Create a little hood for your LEDs by taking a small strip of paper. Bend it in half, but don't fold it all the way. Instead pinch one half of that side and glue the two ends of the pinched side.
Attach the hoods to the LED stands
Step 6: Finishing Touches
Test the color lamp. You may need to map the values of the bend sensors depending how thick the conductive paint strips you made.
All of the LEDs should be able to light up, but I realized that some of the LEDs are more sensitive. In my case, the blue LED was the most luminous while red was the least. Sometimes blue overpower the other three, but I was able to get a small variance of different colors.