Ultrasonic scanner (Part 1)

Part 1, 2

And now, something completely different : here is arduinoos’s ultrasonic scanner !

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This ultrasonic scanner results from the combination of two main components: an ultrasonic sensor and a stepper motor. Both have already been covered in this blog (here and there).

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Both component form the head of the scanner which is screwed on top of a basic camera tripod thanks to additional mechatronic components.

These components are very popular and available at cheap prices on the web or straight from your scrap box. An Arduino platform, a voltage regulator and a stepper-motor driver are also required. Once again these are pretty cheap components that you may already have. Both the voltage regulator and the stepper motor driver will be plugged onto a bread board.

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Both the arduino board and the bread board sit in a custom shell which fits to the stands of the tripod thanks to a pair of clips…

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The principle of operation of this ultrasonic scanner is rather simple. The ultrasonic sensor is mounted directly on top of the shaft of the stepper motor. On each step pulsed to the stepper motor, the ultrasonic sensor performs one (or more) measurements. So that on each completed step, the scanner exports an angular value and a distance. Applying some math results in exporting x and y coordinates too. These data can be used to reconstruct an image of the solid objects surrounding the scanner.

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As the stepper that I choose features 1024 steps, the code will manage to set larger angular resolution that the user may change according to his needs. Same for the full swing of the scan, the user may decide to sweep any range from 0 to 360°.

Although this scanner looks like it has been designed for building maps, it can be used for  measuring the actual sonic beam of the sensor too.

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