Introduction: The Standing Ovation Sensor

About: I'm an enginerd, author, and teacher.

I got a standing ovation once, and it was pretty awesome. It was part of new student orientation at Carnegie Mellon circa 1999, when they hired this company called Playfair. At one point there were hundreds of us sitting in circles on the football field, and if you stepped into the middle of the circle, the rest of the group gave you a standing ovation. I was super shy but surrounded by other similarly shy super nerds, so I stood up, and went to the center of the circle. And got a standing ovation. And it was, as previously stated, awesome. I hope everyone gets to experience that at least once in their lives.

A while ago it occurred to me that it would be great to enter my office to applause every morning. I can see it coming in especially handy on the days I'm really dragging. So I put together this quick circuit so that every time I open my door, I get a standing ovation (well, it just plays a pre-recorded audio file of clapping, but I'm standing, so it counts). If you'd like your own standing ovation every morning, feel free to do the same.

Step 1: Step 1: Collect Parts, Solder Them Together

For this project, you'll need:

Arduino (any flavor will do - I had an old Duemilanove around)

Adafruit wave shield v1.1

SD card


Magnetic contact switch

A power supply or battery pack for your Arduino

Adafruit's awesome guide tells you how to solder everything together. The only additional step is to solder in the contact switch. One leg should go to ground, the other to a digital pin (I used 7).

Step 2: Step 2: Download Applause or Other Audio File

Adafruit's guide also talks you through this part. I found a random audio file of clapping to use that's attached here for convenience.

Step 3: Step 3: Write/copy Code

This is the code I used to run my standing ovation sensor. It's heavily commented and based on several examples, so it should be easy enough to follow. If you don't use my audio file, you'll have to change the name of yours to match. You want to start the code with your door closed, so the first state change triggers the audio to play once, then every other state change the same thing happens. It does not play the audio when the door is closed.

Step 4: Step 4: Mount on Your Door

The speaker itself has a magnet in it, so make sure it's not close enough to the contact switch to make it change states. I chose to plug my Arduino into the wall with a spare power adapter here, but you'd probably get decent life out of a battery pack too.

Step 5: Step 5: Get a Standing Ovation

Close your door, walk in, and smile.

Sensors Contest 2016

Participated in the
Sensors Contest 2016