This Instructable teaches how a basic embedded controller can be programmed to control LEDs (of the primary colors) such that Red, Green, and Blue light can be mixed to create a full spectrum of colors. Optical effects created due to pulsation patterns of light can be explored as well.
The Color Mixer uses a ‘Stamp’ Microcontroller Module from Parallax to control 4 bright LEDs.
The LEDs are Red, Blue, and Green and by controlling which LED is active at a given moment it possible to create a mix of colors from Red to Purple and even White.
Interesting Pulsating and Strobe Effects can be created by selecting a given color and adjusting the pulse rate.
The Color Mixer Circuit can be used as described in these instructions or can be modified to be part your unique application. Code for the controller is included and can be modified to extend the visual effects possible.
The next step has a video of the color mixer is operation.
Step 1: Color Light Mixer Operation Video
Example Operation of the Color Mixer: (ref Video)
The Color Mixer can adjust colors from Deep Red to Bright Purple (and near White) and the light can be made to pulse at varying rates.
Some pulse rates and color combinations create an optical illusion that look like the following: a laser, a plasma stream, and a jet engine exhaust.
Step 2: Adding Parts to the Stamp Carrier Board for the Color Light Mixer
The Color Mixer uses a Parallax Stamp Controller running the Stamp Basic code that is included in these instructions.
Building the Color Mixer requires several items:
**Basic understanding of electronics and how to solder is needed.
**As with all computers circuits construction, the use of anti-static workbench precautions need to be followed. (Static electricity that is not an issue for me and you can damage ICs and other electrical components. )
*Schematics showing how the electrical parts connect to the 'Stamp' module. (ref: the jpg or pdf images of schematics)
*The Basic Code that runs on the 'Stamp' controller. (ref: attached txt file)
Parts for the Color Mixer can be order from companies such as Digikey or directly from Parallax.
The Stamp BS2-IC Controller was used with the Stamp Carrier Board.
Circuit components R1- R4, Q1-Q4, U1, U2, R9 and R8 were mounted to the Stamp Carrier Board using wire-wrap pins, solder and Wire-wrap wire. Wiring for the entire Circuit was completed before the Stamp Controller module was plugged into the stamp carrier.
Step 3: Making the LED Board for the Color Light Mixer
Using a small circuit pref board mount LEDs D1-D4. The LEDs were mounted in a square pattern in the prototype. (ref: image)
The LEDs next have wires soldered to their leads which enable the LEDs to be connected as shown in the schematic. At this point leave the wires about 12 inches long.
Step 4: Prepare Box for Electrical Compoents for Color Light Mixer
Using an electronic project box arrange components as shown.
Noting the size the specific components that you have purchased, drill mounting holes for components and mount each component using the hardware that came with each component.
Components mounted in this step are:
SW1 (the on and off switch)
SW3 & SW2 ( the color and pulse control switches, Note: these switches are momentary switches)
R5 & R6 (Variable resistors which are used to control color selection and pulse rates)
LEDs (D1-D4) on circuit board
Battery Pack (6Volts, Use C or D cells )
Once the components are mounted, solder wires about 1 foot long to each component lead per the schematic.
Step 5: Attaching Compoents External to the Stamp Carrier Board for the Color Light Mixer
In this step connect the components just wired to the Stamp Carrier Board and other interconnections as defined via the schematic. Before wires are soldered in place trim wire lengths and routing of the wires as needed.
With all the wires connected, dress the wires with nylon tie-wraps.
Using an ohm meter check the electrical connections between all components to confirm that circuit is wired correctly.
Step 6: Program the Stamp Controller for the Color Light Mixer
Program the Stamp controller using the attached Basic program.
As the program runs it checks switch SW3 to determine the operation of the color change knob or the color change switch. With each press of SW3 the control of color selection is toggled between SW2 and the position of R5 (variable resistor).
The pulse rate of the displayed color is determined upon the setting of R6 variable resistor.
The colors that are selectable are based upon a set of programmed color patterns that are defined in the program. Colors are created by turning on and off the Red, Green, and Blue LEDs in a very rapid pattern (faster than the human eye can see) ... in some cases an extra Red LED is turned on as well (as in the case of the color called: Ultra_Red (ref program code)).
Each color is a pattern of LEDs (red, green and blue) turned on and off and is created via a sequence of 10 color patterns that are cycled through by the program. New colors can be created by altering these coded patterns.
Step 7: Add the Programmed Stamp to the Color Light Mixer
With no batteries in the circuit plug the Stamp controller into the Stamp Carrier Board, insure the controller is plugged in correctly. (ref the markings on controller and carrier board.)
Step 8: Testing the Color Light Mixer
Now the fun part.
Insure the power switch (SW1) is OFF.
Add batteries to the circuit.
Turn the power switch 'ON' and examine the components to insure nothing bad is occurring ... (like smoke or things getting warm/hot).
Check to see that at least one LED is turned on.
Try turning R5 to see if the pattern of LEDs lit changes (if this does not work... press and release SW2).
With colors being able to change next try turning R6. R6 adjusts the pulse rate of the LEDs.
If these things are working then you now have most of the color mixer working.... but there is one more interesting feature of this instructable! (Next step)
Step 9: Light Tube for Color Light Mixer
In order to see the full effect of the Color Mixer a light tube is needed.
The light tube for the color mixer can made from a clear plastic tube, the diameter of the tube needs sized to fit over the pattern of the LEDs constructed in step 3.
In order for the tube to glow it is best that the tube be either lightly sanded ( internally or externally) or a defusing material such as wax paper, or rolled plastic film, be added to the inside of the tube.
With the tube constructed, attach the light tube over the LEDs. This can be accomplished with either tape or bonding a support ring to the top of the Color Mixer such that light tube fits into it.