Christmasqualizer Is The Next Light Switch Rave


[Kyle] was looking for a way to spice up his boring brick-wall dorm room. The Christmasqualizer he came up with brightens up his room and would make an awesome place for a rave.

The strings of lights in [Kyle]’s Christmasqualizer are off-the-shelf Christmas lights. A simple circuit for the 7-band equalizer was built following this article. The build uses an MSGEQ7 equalizer chip takes audio from any source. The volume level of the seven EQ bands are output to an Arduino over a serial connection.

After the EQ chip was connected to the Arduino, [Kyle] needed a way to switch the strings of Christmas lights on and off. A few solid state relays later, and he was in business.

All the code for the Christmasqualizer is up on github. The sketch is pretty simple – connect the EQ chip as per the article, then connect the relays to the output pins on the Arduino. It’s a fun and easy project that really livens up a dorm room.

25 thoughts on “Christmasqualizer Is The Next Light Switch Rave

    1. Haha. I know =P. It was picked because it worked well and it wasn’t so dirty it was unprofessional. I was originally recording the telephone song by the black eyed peas and had to turn off the camera when they started singing about booty calls!

      1. Given that these are Christmas lights, I’m surprised you didn’t go with Christmas music from, say, TSO

        I hope I got that right, I wish HAD had a comment preview button. I like to proofread my posts for grammar and formatting mistakes.

      2. Haha! Well, when I started building the project, my roommate is jokingly like “okay no christmas music until thanksgiving” and I had to agree that September was a bit too early (but not for walmart, who has 3 christmas sections open as of the second week of september). I did sneak a play of some trans-siberian orchestra in there and it works really great!

    1. That was you? Thanks so much for keeping that up! Seriously that datasheet was getting me nowhere. It’s so different than using LEDs, but it’s a great effect of its own. LEDs just have a different kind of blink to them. Please use 7 channels though… I used 5 (I’m a poor college kid) and it’s just not the same without them all!

      1. The info was originally written by someone named J Skoba – I just happend to save a copy of his site to my PC so I would never lose the schematic for the MSGEQ7. When his site went down I put a copy on my site for someone on the Arduino forum and the rest is history…
        I only used 3 channels (high mid low) in my latest build (see the home page on my site for the video) I mapped the 3 channels to RGB on the LEDs, which makes for a custom color for each “beat”.

  1. Yeah, almost everyone who has ever seen either my RGB Pixel or GE-35 based builds have said “I want one”. I think the MSGEQ7 is a great IC to have in the toolbox for anything having to do with audio.
    Now, if someone would only come up with a similar IC for determining colors of a video signal…

  2. “The volume level of the seven EQ bands are output to an Arduino over a serial connection.”

    Now that is just plain wrong. The MSGEQ7 doesn’t do Serial. Yes, the frequencies are read in series (Band1, Band2 … Band7) but the actual values are not transfered via a serial connection. The output pin of the MSGEQ7 is analog. It outputs the “volume” via a DC voltage.

  3. Actually liked this :-) Would like to see it designed with receptacles so I could just plug in seven different strands of lights – something simple my Grandma could use :-)

    1. I agree, but I’m also new to electronics (6 months of experience now? if that?) I have no idea how I’d throw in demuxer in and still strobe it in time and all. Gosh, if this chip just outputted each channel on its own pin, could you imagine how much bloat that’d drop?

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