The Pandaphone

2014-12-21 23.10.18I was looking for a gift for my friend’s son, who’s about a year old.  I realized that everything I was looking at was just various enclosures with chips that made sound and light…that’s the kind of crap I can do!

So I built a theremin-type thing. It plays notes based on how close you are to its ‘eyes’, which are an ultrasonic distance sensor, and the nose is a small speaker.


Build log after the break.

I prototyped it on a breadboard with an ATtiny85 (the little 8-pin thing).  It worked fine, so I slapped it onto protoboard with some female headers so I could plug in and make changes.

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The case is made of a 6 inch length of 2×4. I sliced it longways twice on the bandsaw, then bandsawed out a cavity in the middle piece in order to make a box.  Two holes for the ultrasonic “eyes” plus one for the speaker “nose”. I jammed a switch on the side and spliced in a 9V battery terminal with a 7805 voltage regulator.

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The battery didn’t want to fit, but a dremel fixed that.2014-12-20 21.29.17

I decided to add an indicator light late in the build, so I spliced a resistor and some thin wire onto this LED and heatshrunk the joint. This got soldered straight onto the board, which quickly became a nexus of solder blobs.

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I realized too late that I needed a pullup resistor on the reset line, so I just slapped one on the back of the board. While I was there, I figured I’d add a decoupling capacitor.2014-12-20 22.01.06

Jamming it all in there. In order to keep the ultrasonic from slipping back, I put dollops of hot glue on the back so it would rest against the back of the case.2014-12-20 22.08.41

My highly well-planned circuit diagram.2014-12-20 23.17.00

I woodglued the front to the middle, and hotglued the speaker into the cavity.2014-12-21 12.34.03

After a lot of trial and error trying to secure it with wood screws, I switched to 6-32 machine screws with tee nuts.2014-12-21 15.26.20

Here’s a video of it in action:

In order to paint and finish it quickly, I stole this dude’s finishing technique and held the piece up with some nails in wood.2014-12-21 15.26.24

I painted it with these paint markers I got a while back.2014-12-21 15.26.48

A test paint on a scrap of wood.
2014-12-21 15.26.44Preparing to paint the real thing.
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The planned art sketched out.
2014-12-21 21.41.57Painting!2014-12-21 21.54.20 2014-12-21 21.57.18 2014-12-21 22.04.09 2014-12-21 22.08.24 2014-12-21 22.20.04 2014-12-21 23.10.18 2014-12-21 23.10.30 2014-12-21 23.10.36 2014-12-21 23.10.42 2014-12-21 23.10.53Dog!2014-12-21 23.30.23Preparing to finish it with spray lacquer, again based on this guy’s technique.
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Removed the ultrasonic and put a woodscrew in the nose to protect the speaker.
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First coat.2014-12-21 23.39.44

Here’s the finished Pandaphone right before I wrapped it:

2014-12-22 10.31.57 2014-12-22 10.32.04

Christmas day, time for unwrapping…

IMG_0437 IMG_0441

Does he like it???

He does!

Hello? Yes, this is baby.



2 Replies to “The Pandaphone”

  1. Pingback: Pandaphone is a DIY Baby Toy | Hackaday

  2. Pingback: Pandaphone: een peuterproof mobieltje - Mancave

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