<ol type="1">
<li><p>Inspired by an Instructable project</p>
<p><a href="https://www.instructables.com/id/LED-VU-Meter-With-Arduino-UNO">https://www.instructables.com/id/LED-VU-Meter-With-Arduino-UNO</a></p></li>
<li><p>Started the project with Arduino Uno.</p>
<ul>
<li>Found that power it with the barrel plug made audio input stable</li>
<li>Tested this theory by using USB power</li>
<li>Suspect this was due to grounding not being as good with the USB</li>
<li>This caused LED's to light even without an audio input</li>
<li>Ended up using an generic Arduino Nano to control the project</li>
</ul></li>
<li><p>Modified an audio mic preamplifier from Amazon to condition the output from the laptop music source</p></li>
<li><p>Ran the output from this to A0 on the Arduino</p></li>
<li><p>Split the signal out to an external speaker</p></li>
<li><p>Used digital outputs listed in the sketch to power the LED indicators</p>
<ul>
<li>For reference, a sketch is the program that the Arduino runs through a loop.</li>
</ul></li>
<li><p>Used pins 10 to 12 as AnalogWrite pin to provide the power to the solid state relays.</p></li>
<li><p>Used a dremel to separate the power to the hot side of the two power outlets</p>
<ul>
<li>Used three of the outlets to power three strings of Christmas tree LED lights.</li>
<li>Used the other outlet to power the Arduino</li>
</ul></li>
<li><h4 id="bonus">Bonus</h4>
<ul>
<li>Using these particular solid state relays, there is still a 10Vac output in <em>off</em> state. It actually worked for good, as the lights are at a nice brightness without a music input.</li>
<li>Kindly leave a note in the comments if this is common to Solid State relays.</li>
</ul></li>
</ol>
<h3 id="links">Links:</h3>
<h4 id="gy-max4466-electret-microphone-amplifier">GY-MAX4466 Electret Microphone Amplifier</h4>
<p><a href="https://www.amazon.com/gp/product/B07C3HXPJ9/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&amp;psc=1">https://www.amazon.com/gp/product/B07C3HXPJ9/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&amp;psc=1</a></p>
<h4 id="solid-state-relay-on-ebay">Solid State relay on Ebay</h4>
<p><a href="https://www.ebay.com/itm/25A-40A-SSR-25DA-SSR-40DA-250V-Solid-State-Relay-Module-Alloy-Heat-Sink/401478280169?hash=item5d79f863e9:g:dkwAAOSwiqFaX3f8">https://www.ebay.com/itm/25A-40A-SSR-25DA-SSR-40DA-250V-Solid-State-Relay-Module-Alloy-Heat-Sink/401478280169?hash=item5d79f863e9:g:dkwAAOSwiqFaX3f8</a></p>
<h4 id="elegoo-for-arduino-nano-v3.0">ELEGOO for Arduino Nano V3.0</h4>
<p><a href="https://www.amazon.com/gp/product/B0713XK923/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&amp;psc=1">https://www.amazon.com/gp/product/B0713XK923/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&amp;psc=1</a></p>
<h4 id="analogwrite">AnalogWrite</h4>
<p><a href="https://www.arduino.cc/en/pmwiki.php?n=Reference/AnalogWrite">https://www.arduino.cc/en/pmwiki.php?n=Reference/AnalogWrite</a></p>
<p><a href="https://www.arduino.cc/en/Tutorial/AnalogInOutSerial">https://www.arduino.cc/en/Tutorial/AnalogInOutSerial</a></p>
<h3 id="my-video">My video</h3>
<p><a href="https://archive.org/details/vid-20191217-192821-no-audio">Sound
Reactive Christmas lights on Archive.org</a></p>
<p><img src="https://ia801506.us.archive.org/34/items/screenshot-20200630-014101/Screenshot_20200630-014101.png" style="width:200px;" /></p>
<p><strong>Edit:</strong></p>
<p>Here is the song I meant to add, to see if it matches my video of the lights.</p>
<p>It is the Trans Siberian Orchestra, Carol of the Bells.</p>
<p><a href="https://m.youtube.com/watch?v=sCabI3MdV9g" target="_blank">https://m.youtube.com/watch?v=sCabI3MdV9g</a></p>
