Introduction: Light Show on Music

About: Indie game developer, Google Play:

I have always wanted an inexpensive way to make a Light Show that would work on music. In this instructable I will show you how to built my Light Show. I hope you love music and lights and that this instructable will be helpful for your future projects. This instructable shows all the steps I went through in designing and building this Light Show.

After doing some research I decided to design and build my PCB. It took me almost 2 months to build and design the it from start to finish. Before starting the actual designing of the project, I did a lot of research on the web. I recommend taking a look at the following websites: . These website will provide you with a ton of information and answer most of your questions on this project.

This project is great for all who love music and light effect.
Please vote for this project in the
DIY Audio and Music Contest.

What is a Light Show?

Light Show is something that has needs more lights to blinking. It can be working with microprocessor and it is programmed, this kind of light show is always working the same way an any time no matter what music is played. The other king of working the light show is that it is connected to the music, this way of work is more funny to watch and really cool to watch it.

Step 1: How It Works :

It works by using filters and amplifiers. The name itself tells us that filters help filter out signals and amplifiers help to strengthen signals.

There are several types of filters:

  • Low Pass Filter
  • Band Pass Filter
  • High Pass Filter

The filter is constructed with the use of resistors and capacitors, but in different weaves, depending on the type of filter classes and falling shut-off signal.

Step 2: Low Pass Filter :

The name tell us that a Low Pass filter that transmits only the low tune.

The reason this works is that the voltage across the capacitor can not suddenly change as we put out the resistance that slows down the charging capacitor and can not output voltage to follow the rapid change of the input voltage. As a result of this is that the high frequency cut off at a point which is called corner frequency. In order to calculate when the filter cut high signals helps this equation that is on a picture.
This equation tells us that the calculated frequency corner, the signal at the output remains unchanged as at the entrance. If the frequency of crossing the border, however, will slowly decreasing signal strength. Each filter is a little bit displaced position of the output signal as the input, but this can be ignored.

Gain non-inverting amplifier while using with this equation: Av=(1+(R4/R5))

To create a passive second class inverting a low pass filter which has at the end amplifier, we have the same equation for calculating the corner frequency, the changed is only equation to calculate the amplification which is: Av=-(R8/(R6+R7))

Step 3: High Pass Filter :

The name tell us that a High Pass filter that transmits only the high tune.

The reason why this works is that the voltage across the capacitor I can not suddenly change. We can imagine that the high-frequency capacitor means a straight piece of wire (short circuit). Real DC capacitors represent the lower frequencies two piece of wire that never touch which means that we have a circuit of open. This is why we do not get the voltage on the output.

In order to calculate when the filter cut loader signals helps this equation, which is the same as a low permeable filter, but we must first calculate the two second class filter separately and then summed up the final results: The equation for the first second class filter is on the picture.

And then summing the individual results and give the entire filter corner frequency: Fcorner(Hz)= Fcorner1(Hz) + Fcorner2(Hz)

Gain inverting amplifier can be calculated with the following equation: Av= (1+R16 / R15)

To create a passive fourth class inverting high-pass filter, which have at the end amplifier, we have the same equation for calculating the corner frequency, changed is only equation to calculate the amplification which is as follows: Av = - (R23 / R18)

Step 4: Band Pass Filter :

The name tell us that a Band Pass filter that transmits only the band tune.

The picture 1 shows the non-inverting band pass filter, which consists of fourth class passive high pass filter, and then followed by third class passive a low pass filter, and at the end of the amplifier. This has the possibility to change the gain (2 options) if the link between JP1 points connected, then we have lower gain of Av=129,2. But if the connection is interrupted and we get a gain of Av=167.6. Corner frequency Fc(high) = 411Hz and corner frequency Fc(low) is 10141Hz.

To create a passive third class inverted medium-pass filter, which is at the end amplifier, we changed only
the connection of the amplifier as shown in the picture 2.

The picture 2. shows the inverted medium-pass filter which consists of third class passive high-pass filter, and then followed by third class passive a low-pass filter. Corner frequency Fc(high) = 1325Hz and corner frequency Fc(low) = 8751,3Hz.

Step 5: Splits Filter :

Depending on the type of filters:

  • Low Pass Filter
  • Band Pass Filter
  • High Pass Filter

Depending on the performance of filters, separated on a:

  • active (with booster)
  • inverting
  • non-inverting
  • passive

The difference is this:

In the passive filters we do not have amplified signal and the output signal is smaller than the input, while in active filters were amplified output signal depending on the number of booster

Passive do not have an amplifier, which is located in the integrated circuit, while the active with

Active filters separated even in the polarity difference between the input signal and output signal:

  • inverting
  • The non-inverting filter

The difference is that the inverting filter turns polarity output signal to 180 ° from input signal (+ → - or - → +) while the non-inverting can not do this.

The classes of falling signal in the locking functioning of the filter (cutoff frequency):

  • first class filter (First Order Filter) → Roll-off 20dB / decade
  • second class filter (Second Order Filter) → Roll-off 40dB / decade
  • third class filter (Third Order Filter) → Roll-off 60dB / decade
  • fourth class filter (Fourth Order Filter) → Roll-off 80dB / decade
  • fifth class filter ( Fifth Order Filter) → Roll-off 100dB / decade

Step 6: Let's Start, Parts and Tools :


  • 3 x 22nF non-polarized capacitor
  • 2 x 68nF non-polarized capacitor
  • 10 x 100nF non-polarized capacitor
  • 5 x 220nF non-polarized capacitor
  • 7 x 1uF non-polarized capacitor
  • 6 x 1N4004 semiconductor diode
  • 2 x LM324N integrated circuit
  • 2 x 14 pin socket for integrate circuit
  • 1 x 15Ω resistor
  • 3 x 18Ω resistor
  • 4 x 100Ω resistor
  • 1 x 220Ω resistor
  • 2 x 500Ω resistor
  • 14 x 1kΩ resistor
  • 4 x 2kΩ resistor
  • 7 x 3kΩ resistor
  • 1 x 10kΩ resistor
  • 1 x 22kΩ resistor
  • 1 x 100kΩ resistor
  • 3 x TIP31C bipolar NPN transistor
  • 3 x Input / output terminals
  • 1 x 2 pin block for amplification
  • LED strip type 5050, 14.4W/m, 5m
  • PCB plate

Total amount = 83parts


  • Solder gun and solder
  • Wire cutters
  • Needle nosed pliers
  • Drill and drill points
  • Hand or powered saw
  • Hot glue gun and hot glue
  • Rotary Tool
  • Sandpaper
  • Digital multimeter
  • thinner
  • rosin powder
  • brush
  • stronger plastic pot
  • Safety Glasses :)

Step 7: Designing a PCB With Computer :

To create a circuit that is fixed, you can choose between hand-drawn and computer design. Before we start with any mode, we need to have absolutely all the components (elements) on the table, because it is necessary for the production rate of each individual element and a range of terminals (pins) element. This is good for us to make a nice visual and not overcrowded circuit, because if you would not have previously elements on the table, it could after the drawing during the manufacture of the elements too compressed or even would not be enough space to be firmly installed in the circuit. When a product is overcrowded and not good is a reflection of incompetence and insensitivity inaccuracies and that the manufacturer has not applied his love of the product.

It is not only important that the product works, the product must consist of 50% visual and 50% of technical perfection. The product will be formed with the help of a computer program EAGLE (Easily Applicable Graphical Layout). The program allows us to draw power plan, and then using it to draw the plate elements and connections. Once you have done the layout elements and links between them we have need before printing connections on a sheet, set in the program Mirror function, otherwise the circuit seen by bird perspective. When pressed on the link list do with a ruler lightly network that we had on the computer while drawing connections is 1/10 inch (2,54mm).

This program is free and can be downloads from this link:

I have made my own PCB board in computer program EAGLE, if you want to use my designed PCB i have posted my file for use in program EAGLE.

Step 8: Preparing the PCB :

Preparation of plates:

We are ready for the production of circuit boards, for the manufacture of the plate is used which is drilled in the form of a network that is 1/10 inch, and has on one side the copper islands.

First, we cut at an appropriate size, taking care that the cut to a bigger surface area than the surface of the links. To have on at least one side type of copper islets blank. Then, purification of copper islands with iron sponge so that on smooth rubbed in one lengthwise (forwards-backwards) and without the circular movements. This work is to get clean copper from dirt from the upper surface that has been accumulated. Clarified top surface of copper needs to shine. Sharp edges rounded off.

The dimensions of the circuit:
Length: 43 in spacing of 1 / 10inch Network (11cm)

Width: 35 in spacing of 1 / 10inch Network (9cm)

Step 9: Solder Part :

Solder part

Then take a cut plate and sheet in which the connections and electrical elements and begin by soldering elements and dragging the links for copper islands.Take care that the soldering tip is always clean, because it is helping to create better connections and faster solubility of tin.

Step 10: ​Verification and Protective Liquid :


Then comes a phase in which the conductivity is checked connections and possible short circuits and what possible missed connections. When we find that all connections are correct and we do not have any error going on a protective spread connection and the lower part of the circuit.

Protective liquid:

This is done on the stronger plastic pot (from an empty glue for wood cut container in the middle and give the cup) and pour thinner rosin powder and stir with a brush so long that the dust in fully decomposition, we obtain the fluid is yellow. If you pour the liquid into a softer plastic cup, after 1 min will eats it from the bottom, since it practically eats things because it is corrosive. When we have a brush greased underside of the circuit, leave the coating is dried, so we links give protection against oxidation. The coating is not relevant when soldering, so you can still fix anything.

Step 11: Troubleshooting :

Socket for integrate circuit :

This error was most unexpected, this type of socket (professional) have begun to generate noise, which resulted light red output which showing the high tune.

To remedy this problem, we removed the old (professional) socket and replace it with conventional and cheaper socket that these noise does not produce.

Step 12: Specifications Circuit and Connection :

Specifications circuit (V, I, W):

  • U = 12VDC
  • I = 2,5A
  • Pmax = 30W

Step 13: Video of Working :

At the video is displayed on the operation of the circuit of which is connected to LED strip of 5 meters with rated power per meters 14.4W/m.

I said before that max output power is actual consumption 30W, this 30W is not the same as this on led strip, which is rated to 14.4W/m.

I hope that you enjoyed following me along with this Instructable! Thank you for reading! Check out the video in the intro!

Please vote and favorite this intructable, I really appreciate it.
Thank you

DIY Audio and Music Contest

Participated in the
DIY Audio and Music Contest

Automation Contest

Participated in the
Automation Contest