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How to build a Smart Lightbulb in a Weekend

blog.kytelabs.com

44 points by rgonzalez 13 years ago · 16 comments

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hmottestad 13 years ago

It's very pretty they put everything into the shell of the bulb. My smart bulb is a regular led lamp that I've run the power through a nice transistor and arduino sitting next to the lamp on my desk. However I have a nice webapp and even a brightness sensor to adapt to light in the room.

Some videos of my lamp: http://fluffyelephant.com/2012/09/two-videos-about-my-led-la...

And a write-up: http://fluffyelephant.com/2012/05/lamp-update/

makomk 13 years ago

Is the Arduino really necessary here? From the description, it appears to be basically equivalent to 3 wires between the Bluetooth module running the actual control code and the transistors switching the LEDs. (Honestly, Arduinos seem to be a bit overused in general...)

  • Falling3 13 years ago

    From the article:

    "Right now, the Arduino isn’t reading serial data from the BLE module, it’s pretty much working as a pass-through for whatever the BLE module says. It reads the value of three of the BLE’s GPIO’s to control each color of the LEDs. In the future, it should read serial commands from the UART and have a big list of awesome things that it’ll do. Naturally."

stephengillie 13 years ago

Neat shortcut -- instead of building your own main-to-5v power converter, you found the best one made by someone else and just used it.

Edit: I just realized you're basically some code away from reinventing LIFX. http://www.kickstarter.com/projects/limemouse/lifx-the-light...

  • rgonzalezOP 13 years ago

    Thanks!... Yeah, much more practical for a prototype.

    Who says we are some code away? Stay tuned for the iPhone App blog post :)

davidb_ 13 years ago

Stuffing the iphone power supply into the lightbulb is interesting. I'm sure if you took the time you could make/find a smaller switching power supply to stuff in there, but using a well-designed, readily available power supply in this kind of project is resourceful. I wouldn't have thought of it.

nitrogen 13 years ago

This is a very cool project. How does it do on lumens per watt?

  • jgonzalez 13 years ago

    We're not sure how to calculate it but we did some crappy math and it got us around 6.2 lumens per watt. Again, we're not sure if this is correct. You can use the following datasheet if you'd like to calculate it yourself. http://www.adafruit.com/datasheets/FLR-100WAS-RGB.pdf

    Overall, it's decently bright but not as bright as a normal light bulb.

    • nitrogen 13 years ago

      If you're running them at full power, I calculated 9.9lm/W by adding the typical mcd values (3700mcd), plugging them and the 50deg beam angle into [0] to get 2.178 lumens, then dividing by the summed power rating (220mW). Of course, this is ignoring the power used by the bluetooth module, Arduino, and waste heat in the power supply.

      For comparison, an incandescent bulb is 15lm/W, while the Hue bulbs are 70.6lm/W. So it's no Hue replacement, but still a cool, fun project.

      [0] http://led.linear1.org/lumen.wiz

      • rgonzalezOP 13 years ago

        Thanks for the thorough calculations, it'll definitely help us moving forward. Also, glad you mentioned Hue bulbs, we were focusing on Bluetooth as our main differentiation factor but we have to cover the basic as well i.e. good lighting.

      • jgonzalez 13 years ago

        Thanks for the explanation :).

GotAnyMegadeth 13 years ago

I'm definitely going to do something like this

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