Vibrating Distance Torch Illuminates the Dark without Light

If you’ve ever had to move around in a dark room before, you know how frustrating it can be. This is especially true if you are in an unfamiliar place. [Brian] has attempted to help solve this problem by building a vibrating distance sensor that is intuitive to use.

The main circuit is rather simple. An Arduino is hooked up to both an ultrasonic distance sensor and a vibrating motor. The distance sensor uses sound to determine the distance of an object by calculating how long it takes for an emitted sound to return to the sensor. The sensor uses sounds that are above the range of human hearing, so no one in the vicinity will hear it. The Arduino then vibrates a motor quickly if the object is very close, or slowly if it is far away. The whole circuit is powered by a 9V battery.

The real trick to this project is that the entire thing is housed inside of an old flashlight. [Brian] used OpenSCAD to design a custom plastic mount. This mount replaces the flashlight lens and allows the ultrasonic sensor to be secured to the front of the flashlight. The flashlight housing makes the device very intuitive to use. You simply point the flashlight in front of you and press the button. Instead of shining a bright light, the flashlight vibrates to let you know if the way ahead is clear. This way the user can more easily navigate around in the dark without the risk of being seen or waking up people in the area.

This reminds us of project Tacit, which used two of these ultrasonic sensors mounted on a fingerless glove.

37 thoughts on “Vibrating Distance Torch Illuminates the Dark without Light

  1. Quite a few projects this year are ultrasonic vision projects and not just limited to the only ones mentioned in the post. Here is my shameless plug for my project:

    I use dual pair of sensors and 6 axis accelerometer to detect stairs and for navigation in a hallway. My sensors are integrated for production/weight reasons and the raw analog signals are used to provide a sonar mode to allow for Sensory substitution as well.

    A lot of my research is on the inner working of these modules. I have done reverse engineering work on the ultrasonic range finder module in my HaD 2015 prize vision project for the current modules in the market as a continuation of [Emily] work on the topic. The project log that specifically covers the reverse engineering module is:
    https://hackaday.io/project/5903-sonar-for-the-visually-impaired/log/20061-ultrasonic-module-lets-get-physical

    There are links that covers the inner working, spice simulation, AVR test code for drive the module.

  2. A great start but….remember that coffee table edge that’s about to realign your shins? The sensor probably won’t pick it up when you hold the unit at waist height.

      1. In a perfect world, perhaps – distinguishing the difference between a low tabletop at 50° and the floor at 55° declination will result in a painful learning curve.

      2. How about this….. If it knows the vertical angle it is pointing at, it should be able to determine an average distance to the ground plane using trig. So when it is pointed somewhat downward, it could alert when the measured distance to the ground is outside a threshold.

        It might even not need to be that complicated. In theory that would allow you to pan the detector along the ground in front of you, and when it encounters an obstacle on the ground the regular pulse rate would modulate in a step fashion, alerting you to the obstacle.

        To my way of thinking, that sounds like a really fun (and useful) enhancement to hack on.

        1. BTW that’s what I use in my design, but mine is a head mounted one, so the distances is on average doesn’t change that much unless you kneel down or something. On my design I can sense the tilt and already worked out the math for these type of situations. https://hackaday.io/project/5903-sonar-for-the-visually-impaired/log/18868-math-is-cool

          The problem with the simple hand held device is that there are too many degrees of freedom – shoulder joint, arm join, hand etc to know if your hand is pointing to the floor or at an angle or level. The simple device itself doesn’t measure the incline angle, so that info is not available.

  3. I didn’t read the article, but one thing that’s bothered me about that PING sensor being used… is it has an INSANELY BRIGHT activity LED – so much so you can see by it.

    So unless they desoldered the LED or covered it with electrical tape, the lightless flashlight probably is bright enough to walk by lol!!!

    1. “So unless they desoldered the LED or covered it with electrical tape, the lightless flashlight probably is bright enough to walk by lol!!!”

      You really should do that and submit it as a hack.

  4. I love the simplicity of this.

    I wonder how it works.

    I can actually see several markets for such a device, depending on actual utility.

    For a blind person, the ease of use and simplistic form factor might actually be a useful tool.

  5. Love this project. Very stealth- very cool. I wonder if you could sneak up on dogs or deer with it?
    Would they hear something?

    Idea- connect 2 peltiers to this, instead of the vibrator. One set hot side, one set cool side.
    Right next to each other. Close objects trigger heat (up to something just above uncomfortable,
    no burning), clear path triggers cool.

    Navigation by temperature, instead of sound. Hell, extrapolate this to other senses- I want an
    entire class of sensory hacks,
    stuff that makes you sense one thing using another sense. Like seeing using heat here, or smelling
    with sound somehow, and whatnot.

    1. I love the idea of mapping senses like this. My experience with peltiers has shown they do not react quickly though. If something is right on top of you and it gets very hot it would take significant time before you could recognize a distance object. The vibrator was intended to act as a very fast response feedback device.

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