2022 Sonoran Foothills Christmas Lights Music Show

A few years ago, I started a project to build a musical holiday lights show. There are plenty of solutions for buying off the shelf kits, but I rarely take the smart/easy route.

Instead, I built a control unit capable of playing songs sequenced to 48 channels of lights. It's a nutty labor of love and I have to keep convincing myself of that with every trip back up to the roof.

If you're in the Sonoran Foothills area, swing on by during the neighborhood lights competition Dec 16-18th. Tune into 87.9FM and enjoy the show!

Dec 12, 2022

This year's theme is National Lampoon's Christmas Vacation, and we are officially up and running for the season now! Coroplast cutouts of Clark, Cousin Eddie, Aunt Bethany, and Todd & Margo were supplied by A Shop For Gifts who offered outstanding customer service and were a pleasure to work with.

I put off the start of my set-up a little too long, so with my son's help we managed to get it all put up and programmed over a few weekends, including some unexpected rooftop debugging sessions. Some extra props have been added to pay tribute to certain scenes in the movie, and my neighbors offered to park their RV next to the house for added effect (luckily the storm drain is several houses up the street...).

The official video is coming soon.

Nov 26, 2021

I'm going for simple this year. Note, I said "simple" and not "calm" or "sedate". It's all floodlights! 6 red, 5 green, and 37 white floodlights, with a Home Alone theme (a few famous characters make an appearance).

Dec 14, 2020

Updated lights this year, plus a band in the yard and an 8ft reindeer on the roof...!

Dec 18, 2018

Competition night!

Dec 17, 2018

The timing is getting better. Still working on a couple quirks, but things are mostly solid.

Dec 15, 2018

Everything is up and plugged in. The only thing left is to iron out a timing issue in the software, but everything else seems to be working. The control box is programmed to cycle between playing Jingle Bell Rock, Rockin Around the Christmas Tree, and Trans-Siberian Orchestra's version of Carol of the Bells. The FM transmitter is blasting the music up to a half mile away and the lights are playing the sequences designed for each song -- just not *quite* synchronized yet. I've got 4 days until the Sonoran Foothills lights competition. No problem...


Here is what the inside of the box looks like when things are playing:

This is what it actually looks like under the hood. Here you can see the 5V regulator in the middle that was missing from my original layout. The Pi has a 90 degree 3.5mm audio connector with a cable leading to a 3.5mm outlet on the box toward the right-hand side of the photo.

I haven't kept track of how many feet of light strings and extension cords have been used, but I'll tally that up when I take everything down. I do have a few pictures that illustrate how crazy this has gotten:

Mar 1, 2018

I've wired up the incoming power to the box. Everything comes through a fuse-protected socket, and into an APC surge protector. The Raspberry Pi will be powered by the 2.4A USB port on the surge protector, and I have the light power coming from the orange plug below, via the surge protector. I wanted to keep everything in tact on the surge protector just in case anything went wrong (APC is really good about warranties and damage), so I epoxied mounts around it and soldered the incoming power to the 3-prong plug of the surge protector (instead of cutting and splicing).

So that I can run this in test mode, I decided to add a light switch inline with the outlets around the edge. This is wired separately from anything else, so the computer and relay boards can still operate despite no power actually going through the relays. I used hot glue around the edges of every switch and outlet just to close the gaps (it's hard to cut an even edge in a thick plastic toolbox).

The layout for the control board has come together. Originally, I was going to use plexiglass to mount everything but the plexiglass sheet I bought was really irritating to work with, so I went with a thin composite board -- much easier to work with.

Everything is mounted to the control board, and the relays are wired for common power input.

Here is everything cleaned up and ready for installation into the box. What is missing from this picture is a 5V regulator that I realized later was needed to reliably provide power to all the relay controls. I used an old laptop power supply to feel 12V to the regulator, which then goes to a screw terminal block on the breakout board for distribution.

Watch the video below to see the relays operate in the correct sequence.

Feb 22, 2018

I've got the breakout board built that will take a signal from the Raspberry Pi and break it out to 48 channels (16 per MCP23017 chip). Using this is a little trickier than just writing control values to the Raspberry Pi GPIO pins, but I get double the number of outputs. All of the communication between the Pi and the breakout board is done through i2c.

The Raspberry Pi has a breakout board "hat" module that provides screw terminal connections for every GPIO pin. I've used this on other projects and it is INCREDIBLY helpful. I highly recommend this as part of a Pi experiment/project.

Feb 21, 2018

The outlets are installed and wired together, just waiting for relays to be connected. Each outlet has the connector tab snapped between top and bottom so they run on independent hot lines. Each is wired in series to a common ground and common neutral. Top outlets have a red hot wire and the bottom outlets have a black hot wire; these will plug directly into the relay outputs.

Feb 10, 2018

This light extravaganza will be powered by a Raspberry Pi computer, with 48 independent relay channels. Here I am testing out the first 16 channels...

The entire control and power distribution will be contained within a toolbox, with the outlets lining the outside.

Next up is to install the pre-wired outlets and build a permanent circuit board for the relay control module.