Engineer Thursday - Using the Wake on Shake


Today is the first edition of a new homepage series. We spent hours brainstorming a clever name and finally settled on (drum roll, please)…“Engineer Thursday.” Ok, so we wanted to keep it simple. But from now on, each Thursday we will have a post from a resident SparkFun Engineer. Today’s post comes from our own Mike Hord - check it out:


A few months ago, we released a new product, the Wake on Shake. Based on a concept originally developed by Nitzan Gadish, an applications engineer at Analog Devices, the Wake on Shake is a low-power board that sleeps at a very low current (less than one microamp) until it’s moved, at which time it turns on an additional circuit, which can be anything the user wishes.

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It’s not just motion that sets it off, however - by adjusting the sensitivity, different types of interaction with the board will wake it up. If the sensitivity is turned way up, taps or bumps can activate the board. Turn the sensitivity way down, and it becomes a tilt detector.

We’ve been having a lot of fun with it since its release; e-textiles expert Dia and I each did a fun project using the Wake on Shake. Here’s a short video showing what we did:

Vimeo version can be found here

Dia’s project uses the Wake on Shake with a LilyTwinkle and four LEDs to make a twinkling night sky that activates when it’s touched. Because of the low power consumption of the Wake on Shake, the painting can hang on the wall for months before needing to be recharged. We’ve tweaked the sensitivity to a point where all it takes is a gentle touch to activate it; we had it turned up higher, but found that when the level was low enough for a bump on the wall to set it off, the vibrations from the HVAC system turning on and off were keeping the lights on too much of the time, killing the battery!

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My project uses a toy bank I got at a small Minneapolis kitsch store a few years back. It’s shaped like the iconic “?” block from the original Super Mario Bros. game that shipped with the original NES back in ‘85. Using the Wake on Shake with its default settings, an Arduino Pro Mini, and our small Audio Breakout Board, I taught my Mario block to give me a satisfying “ka-CHING” whenever I (or anyone else) bump it on the way into my office (it’s hanging in my doorway). I stuffed a little 850mA rechargeable LiPo battery into it, and that kept it running for over five months!

Since the release of this board, we’ve been thinking of this type of item’s potential. What kinds of input would you like to be able to use to activate your products? What can you build with a board that can sit dormant for months without needing to be charged?


Comments 16 comments

  • “What kinds of input would you like to be able to use to activate your products?”

    Telepathy

  • Is there a tutorial for the etextile project that Dia created? The 7 cube is more complex than I want to do. I’d really like to replicate the stuffed animal project that uses Lily Twinkle and Make on Shake.

    • We don’t actually have a tutorial for that particular project, but we do have a tutorial using the LilyTwinkle here.

  • Why did you bother with the Arduino Pro Mini in the Mario block? Couldn’t you have just run the Audio Breakout Board in key mode and have the Wake on Shake trigger it directly?

    • The audio module requires some delay between power up and an edge to trigger the signal.

      In the “original” version–the ugly prototype that I made back during wake on shake development–I actually modified the wake on shake firmware to cover that, using the extra pin header on the board to control the audio module. I will at some point write up the project, and I thought it would be more generally applicable to do it this way.

  • An optical break line version of this would be cool for use in alarm/home security. basically an optical “tripwire”.

  • For any motion activated “intruder alert” type project, I want you to know the green Rebel LEDs can have a dramatic scare effect to someone not expecting it, no picture or words can describe what those innocent looking little things can do, Wow!

  • I love the coin block idea! I’m a big fan of the game and I need to make myself one now! Great video guys!

  • Well done, I’ll use this to power my senior project which is an electronic walking aid for visually impaired. I’ll use it to power the circuit only when the person walks. But still not sure if it’s capable of providing 5V output or it’s only rated at 3.3V.

    • The board says it will run anywhere from 2.5 to 5.5 volts (or something like that), so that will work.

      A walking aid? That sounds awesome. However you would probably want to change the wake on shake to wait a few minutes before powering down. That way, if the person is standing on a street corner it’s still on (not sure if it needs to be, but just a thought I came up with).

      • Thank you, I’ll post the entire project here or in youtube when it’s done. The idea is to design a device that maps the area surrounding the person, and defines the type of obstacles using neural network algorithm and alarm him accordingly through vibrations. This will give him free hands instead of the conventional sticks. Thank you again

  • I think it should float in the air like in the game.

    • I wish. If I could make things float in the air, it would be the ultimate office organization tool. No more digging through the piles of crap on my desk for my digital caliper!

      I often wonder if astronauts returning from the ISS have a hard time adjusting to things not floating where they are released, and constantly drop stuff from a moderate height for a few days before remembering that stuff won’t stay where it’s put.


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