In this Instructable I will be showing you how to create a light reactive LED system. In this clip, I used a single color LED strip, but you you can use a single LED, multiple LEDs wired together, single color or RGB LED strip, it just depends on what you are trying to build. The set up is fairly simple, the component list is fairly basic so if you are a tinkerer you should already have the majority of the materials laying around. If not, I will post links to the components I used so you can order parts and get to work! 

In the following link you will see the entire setup. Obviously you may arrange it anyway you would like, I just kept everything close and compact for the sake of an easy video. 


Step 1: Components

For this project you will need the following:

1) LED  ~$20 (with shipping) 
- For this project I used a solid blue LED strip which I purchased on amazon. These 5 meter SMD 5050 strips can run around $70 in retail stores so I though I would be taking a chance purchasing something priced under $20, but I was not disappointed in the least. I'm sure there are better quality lights out there, but if you plan on cutting these up and have no real game plan you wont feel any guilt putting these through the ringer.

2) Mini breadboard  $5

3) Arduino Uno  $30

4) Solid core wire  $2.50
- For anything involving breadboarding, do yourself a favor and stay away from any stranded wire. It will just end up getting frayed and hard to manage. Solid core is the way to go. I also like to choose at least two different colors for my wire to keep grounds and powers visibly separate. It makes troubleshooting and wiring easier in the long run when dealing with a lot of components.

5) USB A to B cable  $4
- This will be used to upload your Arduino LED code to the Arduino Uno board

6) Wire cutter/stripper $5
7) Parallax Sound Impact Sensor $10

8) Wall Adapter Power Supply - 9VDC 650mA $6

Total cost will be a bout $80 but keep in mind, all of these components are completely reusable. You can recycle them into a multitude of projects in the future so try not to worry about the cost. Think of it as building up your technical tool box :)
How do you use multiple LED strips (somewhat new to Arduino)?<br><br>Thanks in advance.
<p>is it possible to use a battery for the power supply as id like to take this outside to test it and record it on video for a uni project??</p>
<p>Is there any way to do this with an audio input jack like for mp3 players instead of a sound impact sensor, so that you can cut out possible back ground noise.</p>
<p>I've also wondered how to do that... So I'm gonna do some research and if I design a functioning circuit I'll post it on here :)</p>
<p>Any luck, MrLucass? :)</p>
<p>This 9 STEP is easy to do</p>
<p>Hello,<br>Great tutorial.<br>I am trying to make it, but my led strip won't go on. Everything is hooked up right, but the led strip doesn't light up.<br>What could be the problem? I hope that anyone can help me out.</p>
<p>I made a very basic version of this. I didn't buy an LED strip because I wanted to test it out first. My best recommendation is to not cut corners. The sound sensor is not the same one that is used in the instructions. I found it on Amazon for about 8 dollars (plus it had Prime shipping and I was being impatient). While it technically *works*, the decibel threshold is set much higher than I would like, even with the most sensitive setting. This meant that it would not pick up ambient sound easily and it would only work effectively if I placed the sensor directly next to my speaker.<br><br>Otherwise, great project, especially if you're new to arduino. One thing I did was swap the LED brightness values (the analogWrite(LEDstrip, 255) portion of the code). As the author previously mentioned, 255 means &quot;off&quot; and 0 means &quot;on&quot;. I wanted the lights to pulse when the sensor sent 1, so I had the &quot;if&quot; statement write 0 and the &quot;else&quot; statement write 255. I also lowered the &quot;off&quot; value to 250 so that the bulbs are always a bit dim, even if no music is playing.<br><br>Another thing you can play around with is the delay() value. This essentially will tell the bulb how many milliseconds it should remain off (or on depending on how you set the analogWrite() values). I lowered mine from 10 to 2 and noticed a very slight improvement on how it reacts to the music, however, 10 will probably be ideal in most cases.</p><p>Very cool project and great idea for parties! I will definitely have to pick up the better sensor and the LED light strip. I have a beer pong table that I would love to mount this under :-)</p>
<p>Can I use any of the cheap ebay sound sensors in the same way?</p>
<p>As long as it has power, ground, and a signal/output pin, it should work. Be wary though... the same thought went through my head and I found one for 8 bucks on amazon (http://www.amazon.com/gp/product/B00AF2GB1U?psc=1&amp;redirect=true&amp;ref_=oh_aui_detailpage_o00_s00) and, while it works, it only is effective for extremely loud noises. I basically had to put the sensor right next to my speaker in order for it to work effectively. I would recommend just getting the sensor that is in the description and not cut corners.</p>
<p>Does this project use the breadboard at all? It's not included in the schematic.</p>
<p>It does, I just made an assumption people knew how to wire the breadboard with my description. I can make another schematic with the intermediate bread board connections though!</p>
<p>I understand how the breadboard works, and I'm assuming that the arduino's ground and vin connect to the breadboard, and the LED connects to the breadboard as well, taking the arduino's vin. Is this correct?</p>
<p>You got it :)</p>
<p>Hello GraziCNU, I am new to the entire breadboard idea and would like to ask if you could post the schematics for the breadboard connecting to the arduino and sound sensor. If you could message me or reply to the comment, it would be greatly appreciated!</p>
<p>Hey GraziCNU, I know this schematic was a while ago but is it possible you can post a bread board schematic. I am new to this and want to add to the setting of my bedroom. The wiring schematics already posted are just a bit confusing and i cant discern where to put the wires in the bread board alone from the video. Any help would be great!</p>
<p>Hi, this instructable has been so much more informative than every other one I've tried, but what if I was to use an RGB LED strip? I saw your code in a previous comment but what about wiring? It has 4 leads instead of one, and it seems that one is for power and the others are for Red, Green and Blue, although I don't know what exactly that means in terms of power and voltage.</p>
<p>How do I create this using wifi or Bluetooth connector, instead of a sound impact sensor? </p>
<p>Super cool tutorial and application! My one question is how do you specify the voltage going to the LED? Is that programmable in the Arduino as well? I wouldn't want to rig all this up and then fry my LEDs (I want to use high powered ones) . </p>
<p>Can you advise on which pins to connect extra leds to as at the moment I am just using singal leds</p>
<p>I have reread this post about 2 weeks trying to find out why the Sound impact sensor will go with the music but the LED strip will stay on. I would love someones input on this thank you </p>
<p>If I know there should be resistors....</p>
<p>Sorry, I mean Transistors.</p>
<p>Hey! I have 12V 2A LEDs you said power supply should go in Arduino (There where comes the battery) but wouldn't that burn the Arduino?</p>
<p>And my LED strip has 4 inputs like oooo I don't know if they are RGB and GND. Please help :)</p>
Hi I cant seem to get the arduino code to work with my uno r3. When compiling it comes up with various errors such as led strip was not declared in this scope and invalid preprocessing directive #DEFINE and in function 'void setup () '. Please reply as this looks likable an awesome project!
Say I wanted to use this set of RGB LED strip <br>http://pages.ebay.com/link/?nav=item.view&amp;alt=web&amp;id=291120524106 <br><br>How would I set everything up?
<p>Hi, I really like your project and I've built it, but I need so help with contextualizing. I am doing this for a class project, and I wanted to just add a PIR motion sensor as an on and off switch for the reactive leds. Would appreciate any help.</p>
<p>So I'm really new to electronics and I am attempting to do this with 1m tricolor LEDs from RadioShack. However my LEDs have 3 leads at the end to plug into my Arduino's ports. Also I can't see any noticeable reaction from my sensor, even when I replaced the strip with a single LED in the breadboard as was shown in the picture of the circuit. Any suggestions as to what might be going on?</p>
<p>Try connecting your sensor to analog instead of digital. Then replace the word digital in the code, with analog. Make sure to change your setup accordingly as well. As for the tri color lights you will notice that they wont listen to the sensor. This can be solved by putting a 0 in void send_1M_pattern(const unsigned long data[0][10], int pattern_no, int frame_rate).</p>
<p>Ok, I made this project and I got it to work only with USB power.. if i plug in my DC power the project doesn't work (light stays on all the time - blinks very little with the sound). something wrong with my Arduino?</p>
<p>i am having some troubles the sound sensor is not picking up anything and i was wondering if it has anything to do with the sensor, it&acute;s the following http://www.dfrobot.com/wiki/index.php/Analog_Sound_Sensor_SKU:_DFR0034#Specification</p>
<p>Is there anyway to program it to only pick up bass frequencies? From 10Hz to 300Hz?</p>
<p>From the video, it looks like it's programmed so that the LED is always on, and then during big bass moments it cuts the light off. Is there a way to program it so that it can be the other way around (the LED only illuminates during the bass hits)? This is my first arduino project- thank you for the inspiration!</p>
<p>Thanks for the feedback man! To get the behavior you are looking for, just swap the following instances in the code: </p><p>analogWrite(LEDstrip, 255);</p><p>analogWrite(LEDstrip, 0);</p><p>255 is the highest pwm value (essentially just a binary &quot;on&quot; at this point) and in my example I set that as the starting state. 0 is a binary &quot;off&quot; which I set as the behavior for when the impact sensor sends out a signal. Just make the initial state 0 and the trigger state to be 255. Let me know if you have any questions!</p>
<p>Awesome- thanks so much!</p>
<p>very misleading. You show a rgb led strip in your main picture but then fail to explain how to set it up. You explained the concept well though. </p>
<p>Actually, I only own a single led strip haha (the single blue strip that was pictured throughout this tutorial). Am I missing something?</p>
<p>How can you let the led strip work because when i made it the led's doesn't work. The scematic is for 1 led and not for a led strip who needs 12 volt. Can somebody help me with this problem ??</p>
<p>The LED Strip should have LEDs internally wired in parallel. I just used the single led to minimize clutter. The connections with the strip should be the same, one power one ground. The LEDs will be dimmer with the 9V supply I used, but they are rated for 12V. Does this clear anything up?</p>
<p>There are plenty of tutorials and probably instructables that describe hooking up led strips to Arduino. Simply put: use a transistor as a switch for the LED strip.</p>
<p>i need that kind of answer also :S</p>
<p>Hi</p><p>I am having problems. When i connect the led ground to the output of the sensor this works fine but when the arduino is connected the leds just stay on. Do you reckon i have a dodgy arduino or is there something wrong in the code others have had issues with?</p>
<p>Would you be able to tell me what GPIO pin are you plugging it into?</p>
<p>Wait i dont get it, how does the LED strip get enough power since its 12V, and we are powering arduino with only 9V. Can this thing be done without arduino, just a plain connection from parallax to led strip?</p>
<p>It is just dimmer with 9V as opposed to 12V. It can be done without an Arduino if you wish. </p>
<p>How many LED strips can you control with one sounds impact sensor?</p>
<p>As many as PWM pins you have access to. </p>
<p>Great post man. I am no way educated at tech things, and I am wondering how this would work for what I have in mind. I originally was going to buy RGB light strips for the insides of my drums that pulse or strobe, etc. Seeing this thread though gave me a much better idea. How exactly does it work. For instance, could I program this to cause the light to activate every time I strike a drum?</p>
<p>You can use this exact set up for that. The sound impact sensor has a sensitivity dial. If you put it in your kick drum, just decrease the sensitivity so it only picks up the kick head and not any tom or cymbal noise. </p>

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