Introduction: Sonar Headset

This sonar headset enables the wearer to "see" head-level objects using an ultrasonic sensor and a buzzer.

In media you often see the trope of a wise blind monk who seems to be able to orient himself perfectly without eyesight. This inspired me to start this project and make the wearer feel like a person with a superhuman ability. Sadly I wasn't able to make the project in a blindfold, but I am happy with the headdress that I did make.


  • Arduino Uno
  • (1 or 2) Buzzer/speaker
  • (1 or 2) Square force-sensitive resistor
  • (1 or 2) Ultrasonic sensor HC-SR04
  • Solderable breadboard
  • 9V battery holder with on/off switch
  • Jumper wires
  • Soldering tools
  • Access to a 3D printer + filament
  • Hot glue gun
  • Scissors
  • A thin plastic oblong bucket
  • Scraps of foam for inside padding
  • Some nice looking fabric

Step 1: Step 1: the Code

Firstly, I began writing the code for this project. With the link below you can access the repository containing the three iterations of the project, with v3 being the latest and the one I personally used. v2 is more advanced; using two ultrasonic sensors for a wider viewing angle, two force-sensitive resistors to refrain the user from sticking their arms out to navigate and two speakers.

The device only starts beeping when the force resistor is pressed, and the beeping goes faster and higher in frequency the lower the registered distance by the ultrasonic sensor is.

Step 2: Step 2: Planning Out the Hardware

In this schematic I planned out the build, mainly to have an overview of how the wiring should be. The second schematic is for when you want to build the more complex version.

Step 3: Step 3: Modelling the Enclosures

The first file is meant to house the Arduino Uno, battery, and ultrasonic sensor(s). Note that I forgot to add holes for the Arduino's USB connector and power jack in the model, which I later had to drill causing a moderately messy look.

The second is meant for the speaker(s)/buzzer(s) and force resistor(s). The small hole is meant for the force resistor's jumper connections to poke through. The larger hole is for the speaker or to hear the buzzer through. A small hole is also added for wires to pass through but I advise you to make it larger just to be sure.

Step 4: Step 4: Soldering

The way I soldered all my parts was kind of a mess the first time around. When I tried again I had a more step by step approach to it, making sure every part and its corresponding wires et cetera were functional. I did this by using a solderless breadboard. I went from buzzer to force resistor to ultrasonic sensor, having all their ground wires and VCCs come together on separate pieces of breadboard. Everything was pinned into the Arduino Uno instead of soldered due to my inexperience and fear of failure.

In the end, I simply glued the pieces together with hot glue to make them whole and ready to be attached to the helmet.

Step 5: Step 5: Making the Headset

To make the helmet you simply take a plastic bucket that's easy-ish to cute into with scissors. You cut out strips or holes where you want the enclosures to go and glue them in using your hot glue gun. For some extra comfort for the wearer, I glued in some foam scraps, which also help in keeping the helmet from moving around.

Using a long patterned sash I had laying around I decorated the helmet a bit, covering up the earpiece and some damaged parts where the plastic cracked.

Step 6: Step 6: Done!

You now own a quite unwieldy piece of hardware, congratulations! I'm probably going to disassemble it to use the Arduino for another project but it was at least a lot of fun to build this thing. Enjoy this picture where my second or third chin is proudly displayed along with my creation.