Handheld Low-cost Ultrasonic Sensor with Audio Output

Hi Everyone,

Based on a request, I have put this together as a complete How-To on the ArduinoInfo.Info WIKI HERE: It looks like this:

This is simple: An Arduino/YourDuino, an UltraSonic Sensor and a beeper. Example code is provided.

It senses the distance to objects up to 2 M (6 feet) in front of the sensor and produces audio beeps that denote the distance. There are 3 zones with beeps getting faster in each zone and then switching to a high tone in the next zone. The last 25 cm can sense small differences down to about 2 cm.

The usual problem is taking something that works, like this: and packaging it so it is portable and will stand up.

I am always lurking through Walmart and Home Depot etc. looking for Stuff That Could Become Arduino Parts.

At Walmart I found the $3.77 waterproof lantern used in this project. It could be used for lots of other Arduino-based projects that need an outdoor case, batteries and maybe an on-off switch. Like remote temperature / humidity / Other sensing with an nRF24L01 radio, Wildlike sensor / Camera control. Etc. Etc. If anyone makes a project based on that case, please let me know and I'll add it to the ArduinoInfo.Info WIKI:

Also, this project is now linked to a section called Understanding the Science Behind the Ultrasonic Distance Sensor (click): That in turn links to Educational Lesson Plans and a SlideShow that can be used in the classroom (My wife is still updating that). If anyone uses this in a class or helps a teacher do this please let me know. I may make a low-cost parts kit available.

Any feedback or suggestions appreciated!

That's an ingenuous idea. I'm wondering whether it was possible to keep the lens cover in place. I suspect not, but if you were able to get the ultrasonic sensors working through it the project might even still be waterproof as well.

Thanks Peter.

the project might even still be waterproof as well.

I wonder about that. I'm sure the ultrasonics won't work THROUGH the lens. I wonder how "Moisture Proof" they are.

There are car sensors that use ultrasonics for parking and collision avoidance, and they must be Out There in the elements?

Anyone know about the 'waterproof' issue? Semi-waterproofing the existing low-cost sensors? Waterproof transducers that could be interfaced to the low-cost electronics?

Other: Anyone seen any cool audio-frequency echo stuff done with Arduino? I'd like to work out a project that schools could use to show the principles behind this. A friend who teaches 5th grade here in Vermont has the kids go outside in between class changes and clap at the building wall from 200 feet away to hear the distinct echo. Doing that with a microphone and oscilloscope would be cool. Hmmmm...

I like questions. Once in a while I get an answer :)

I remember a very similar experiment when I was at school where the teacher had the class clap in cadence with the echo, and by measuring the clapping frequency and distance to the wall we got a surprisingly accurate estimate of the speed of sound.

by measuring the clapping frequency and distance to the wall we got a surprisingly accurate estimate of the speed of sound.

I'll suggest that to teachers I work with!