DIY ZigBee Therapy Lights Are Hue Compatible

Working on a project into the wee hours is hardly uncommon for us hackers, but if you’re consistently sleeping until the afternoon, it’s possible you’re suffering from a condition known as Delayed Phase Sleep Disorder (DPSD). Put simply, your body’s internal clock is out of alignment with the world around you. One of the ways to treat this condition is to expose yourself to bright light in the morning, which can help you wake up and feel more refreshed. Unfortunately, these so-called “Bright Light Therapy” boxes tend to be pretty expensive.

Looking for a way to treat his own DPSD, [Edward Shin] decided to build his own light box based on the research he’d done on the various commercial offerings out there. After all, a box full of bright lights that operates on a timer doesn’t seem particularly complex. Of course, in reality there’s a bit more to it than that, but so far the results are certainly promising.

The first decision [Edward] had to make was what kind of light he wanted. Classic light therapy devices, often used to treat Seasonal Affective Disorder (SAD), tend to be full spectrum lights that try and simulate sunlight. But in his research, he found a paper from Nature that explained the melanopsin in the human eye responds primarily to blue and green light. But as intense blue light can apparently lead to macular degeneration, he decided to go with green.

Since [Edward] already uses the Philips Hue system for his home’s lighting, he wanted to bring his therapy light into that ecosystem. The idea was that he could easily schedule his new green light box to go on when he wanted to wake up in the morning. So he used the Mesh Bee from Seeed Studio which not only supports ZigBee, but for which software is available to emulate a Hue bulb. Then he just needed to pair that with a sufficiently beefy LED driver and some 510 nm emitters. Everything is enclosed in a box made of laser cut wood that’s designed to hang from the headboard and shine down onto his face.

Over the years we’ve seen a number of similar projects trying to address SAD, so the idea of a hacker tweaking the concept to tackle DPSD seems a natural enough evolution of the idea. Just remember to speak with a medical professional before coming up with a homebrew treatment plan.

DIY Lamps Brighten Winter Blues

As you know, winter is coming. For a lot of people this means that Seasonal Affective Disorder is beginning to set in. [Luke]’s mom already has a light therapy box. It’s one of those commercially available ones that uses fluorescent bulbs and leaves a lot to be desired in the full-spectrum light simulation department. [Luke] jumped on the opportunity to design a better one.

The standard of quality for light therapy units is a rating of 10,000 lux. While lux definitely matters, the rating is a misleading selling point when given on its own. One of the other important factors in mimicking the sun is the Color Rendering Index (CRI). CRI is basically a rating of the bulb’s ability to imitate the color reproduction of natural daylight. The ratings run from 0 to 100 but in reality, the highest-rated bulbs of any kind top out around 98.

For all the fluorescent bulb-bearing light therapy units out there, those bulbs have pretty low CRI ratings. [Luke]’s project page provides emission spectra graphs for a number of bulb types, and we can see how his choice of ceramic metal halide bulbs stacks up against fluorescent, incandescent, and LED bulbs. One of the few downsides to this type of bulb is that they have long startup times.

He ended up making two light therapy lamps, one of them directional and the other omni-directional. They both use ballast-controlled ceramic metal halide bulbs. The ballasts are necessary to provide the high starting voltage that these bulbs require. The omni-directional light is built into a large hurricane candle holder. A lamp holder is fixed into the base and wired to an external ballast box. The directional lamp is a self-contained unit, and [Luke] is happiest with this one. It’s flat and rugged so it can be placed on top of a bookcase and the light bounced off of the ceiling for pleasant, indirect coverage.

We’ve seen a couple of alarm-clock wakeup light builds here, and we’re thinking this would make an awesome mashup.