DIY Christmas Lights

December 24, 2011 Meet iFixit — Bob

‘Twas the night before Christmas, when all over the house
The lights were flashing like crazy, thanks to Carl Friedrich Gauss.

Here at iFixit, we’re natural tinkerers, tweakers, and fixers. Many of us spend our free time on side projects and activities which could only be described to normal people as “crazy” or “insane”. Mine happens to bring Christmas cheer to local family and friends, so I thought I’d share it with all of you this year as well. And it probably falls into the “crazy” category.

The Christmas lights I’ve put up at my parents house for the past few years would make Clark Griswold proud. Yes, it’s one of those displays where the lights flash in sync with the music.

Now I could have gone out and purchased an off-the-shelf solution (like a Light-O-Rama system), but that’s just not how I roll. It would be way more fun to build this thing myself! So back in fall of 2008, armed with nothing more than a bit of money and a half-complete bachelors degree in Computer Engineering, I set off to build my own animated Christmas lights show.

Like all good engineers, I started by doing research. Lots and lots of research. I had plenty of experience building digital systems that ran on DC power at a friendly 5 volts, but controlling 32 channels of Christmas lights running on 120V AC power was new to me, and the last thing I wanted to do was burn down my parents’ house for Christmas.

After reading a few scattered articles I’d found around the web, I stumbled upon the Do It Yourself Christmas forums. DIY Christmas is a place for light show tinkerers to meet up, share experiences, and provide tips on everything from hardware controllers to sequencing music. These were my kind of people!

I opted to design my own controller rather than get in on a group-buy for an existing design. To save time, I decided to piggy back on the FPGA board I’d already learned how to use in school. I just needed to design a peripheral board that would let me control 32 channels of lights.

The FPGA board on the left receives lighting information from a computer via the serial cable for each of the 32 channels. Each channel is represented by a single byte, where 0-255 represents 0% – 100% brightness. After decoding each channel, it controls 32 outputs which travel over to the board on the right. For each of the 32 channels, the board on the right will show its status on an LED and send it out to the yard over a standard Cat 5 Ethernet cable.

That bridge board in the middle? That’s a painful reminder that no matter how rushed you are to get something done, you should always double check things you use from the internet. I happened to find a PCB design for the large connector that someone had been kind enough to post on their blog, which saved me a lot of design time because that connector has 50 pins on it. Unfortunately, the original author had connected all the pins backwards, so pin 1 was actually pin 50, pin 2 was actually pin 49, and so on. That bridge board was something I threw together quickly to reverse all the pins on the connector.

Out in the yard, there are 8 electrical gang boxes, each of which has four outlets. These four outlets are individually controlled by the four channels that come in over the Ethernet cable. The power itself doesn’t come over the Ethernet cable, though. The Cat 5 wire inside is so tiny that it can’t handle powering the lights, so there’s a small board inside each gang box called a solid state relay.

The control signal over Ethernet is just 5V and a couple milliamps. This needs to switch 120V at several amps, depending on how many strands of lights I have plugged into the outlet. This calls for a relay, which is basically just an electronically-controlled switch. When my low-voltage control electronics trigger the relay, it opens the floodgates for the wall socket power to come through. This lets you control big-power things with small-power electronics.

An important part of this setup are those tiny square black chips in the picture. Those are opto-isolators, and they’re pretty clever little chips. The last thing I want is a stray power surge in my high-voltage circuits to get into my low-voltage circuits, because that would most certainly destroy a lot of expensive electronics. Those chips allow you to keep the two sides safely isolated. When the low-voltage side triggers the opto-isolator, it turns on a tiny LED inside the chip. That LED triggers a photodetector, which turns on the high-voltage side of the circuit. The two circuits are linked, but completely electrically isolated from each other. Cool beans!

The last piece of the puzzle is sequencing the lights to music. Thanks to the hard work of a fellow DIYer,  Vixen is freely available software for doing just that . It even has a plug-in system if you want to make it run your own custom-built controllers, like I did.

It’s been a lot of work getting the display up and running. Sourcing parts, designing logic boards, writing embedded control software, plugging in all the lights, and sequencing the show certainly takes quite a time commitment, but seeing the smiles on peoples faces when they watch it makes all the work well worth the effort every year.

From our epilepsy-inducing houses to yours, have a very happy holidays and a wonderful new year!

But I heard him exclaim, as he drove out of sight
Merry Christmas to all, and to all some bright lights.

Holiday Gift Guide

December 13, 2011 Hardware, Tools — Miro

Alright, friends. It’s that time of year again—to reach into the pocketbook, bust out the pepper spray, and face the hordes of maniacal shoppers.

But wait! You may not need pepper spray this year. We want to make it easy for you to get gifts for your loved ones. We’ve drafted a list of top-notch gifts and stocking stuffers for the tech- and repair-folk dear to you.

What’s even better than a list of great stuff to buy? If it were free. Well, how about the fact that it’s all available right here on iFixit? Spare yourself a chaotic trip to the mall and check out our goodies right now. If that’s not reason enough, check out MJ’s assessment of our holiday wares:



New Pro Tech Base Toolkit

December 13, 2011 Hardware, Site News, Tools — Kyle Wiens

Our Pro Tech Base Toolkit has been a hot item ever since we released it last year — repair techs, DIYers, single-parent moms, and even secretive 3-letter agencies have used them to open their devices.

Not content to rest on our laurels, we’ve spent a year asking our teardown specialists, customers, repair shops, and tool geeks worldwide how to make it better. We paid close attention to their advice, and we’re excited to announce our new 54 Bit Driver Kit and Pro Tech Base Toolkit!

So what’s new? First, we’ve substantially improved our 54 Bit Driver Kit. Some highlights include:

  • Pentalobe bits to open and repair popular Apple devices such as the iPhone 4, MacBook Air, and MacBook Pro.
  • T7 through T20 security bits to fit Torx security screws with a pin in the center.
  • A full line of metric nut drivers.
  • JIS bits to fit the screws found in digital cameras, R/C helicopters, and other high-end electronics.
  • A custom 1/4″ to 4 mm adapter to allow our 4 mm precision bits to be used in standard 1/4″ screwdrivers with larger handles, ratcheting handles, or torque drivers.
  • A 60 mm extension that doubles as a T-handle, making it easy to get extra torque and remove stubborn screws.

We’ve kept all the great features of our driver kit including the precision machined, magnetized driver and a full complement of flathead, tri-wing, Phillips, Torx, and hex bits.

MJ provides a nice overview of the new 54 Bit Driver Kit here:

While our 54 Bit Driver Kit is the most capable electronics repair screwdriver set on the planet, getting inside many devices requires more than just a screwdriver. That’s where our Pro Tech Base Toolkit comes in. We’ve carefully selected the components to include the most useful tools for releasing tabs, disconnecting connectors, getting into tight spaces, and picking up small parts. To keep everything portable and well-organized, we designed an all-new tool roll to house everything.

Kit contents:

Want to see more? Watch MJ show off the new Pro Tech Base Toolkit:

We’re offering the Pro Tech Base Toolkit at a very affordable $59.95, and we’re also selling the upgraded 54 Bit Driver Kit set for just $24.95. Give the gift of sweet repair success to your loved ones this Christmas.

University Technical Writing Project

December 6, 2011 Site News — Miro

Several thousand user-contributed repair guides have been published on our site since we released our repair guide creator to the world. And that’s no coincidence. We’ve been working with the English department at Cal Poly since September 2009 to develop a technical writing curriculum centered around a device repair manual. In fact, students from across the nation are responsible for the majority of user-created content on our site; a total of eight universities now peruse the iFixit project.

The curriculum requires a group of technical writing students to document how to repair a device — either one provided by iFixit, or one of their own choosing. In return, iFixit provides the tools, materials, and instructions for the students to successfully take apart and photograph a device. The entire curriculum (including tips on photography, writing style, and deliverables that need to be turned in) is hosted on iFixit, so students have access to it anytime, anywhere.

After two years of development, we’ve seen tremendous benefits for everyone involved:

  • Students make a noble contribution by writing guides for real electronic devices, all the while learning modern communication techniques by using pictures and text to relay what they learn.
  • Students have a clear set of deliverables that they can show off to family and friends, and even put on their resume at the end of the term.
  • Professors gain access to an easily-startable, easily-maintainable project. Our collaboration with Cal Poly helped us develop several tools for professors that make it easy to keep track of students’ contributions during the school term.
  • The world has yet another open-source repair manual that can be used to fix the device.


Student group shows how to adjust the derailleur on a bike.

Student group shows how to adjust the derailleur on a bike.

The vast majority of student contributions result in fully usable, well-written guides. And given our flexibility with project devices, we’ve published everything from a stellar PSP 2000 repair manual to a great set of repair guides for a Volvo 740.

With the help of Cal Poly, Ohio State University, CSU Los Angeles, University of Maryland, Cuesta College, James Madison University, University of Wisconsin Stout, and University of Maine, we’ve been able to publish over 350 student-authored service manuals (comprising over 2,000 guides). That’s a great start, but there are still thousands of devices that require repair manuals.

We would love to include other universities across the United States. Our online-based program easily scales to accommodate several more schools that might be interested in our program. So if you know of a professor or other faculty member at your local university and think they might benefit from collaborating with iFixit, please send them our way!