Planet Arduino

In our years here on Hackaday, we’ve seen our fair share of musical hacks. They even have their own category! (Pro Tip – you can find it under the drop down menu in the Categories section). But this one takes the cake. [Andrew Lee] is a student at New York University who had a task of creating a project for his physical computing class. In about 60 days time; he went from dinner napkin sketch to working project. The project is quite interesting – he’s made an instrument that plays music as you move your head.

It works as you would expect. An accelerometer in the user’s headphones feed data to an arduino. There are four (3D printed of course) buttons that are used to select the the type of audio being played. The operation goes as such:

1. Press button.
2. Bang head.

[Andrew] speaks of a particular satisfaction of hearing the music play in sync with the rhythm of head movement.  Be sure to check out the video below to see the Nod Bang in action.

Julia needed a place to rest her cool, new headphones when she wasn't using them, so her dad made a quipping Deadpool head.

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The post Deadpool’s Disembodied Head Shares a Catchphrase When It Holds Your Gear appeared first on Make: DIY Projects and Ideas for Makers.

Where you might see a can, [Adam Kumpf] sees a robot. [Adam’s] robot (named [Canny]) doesn’t move around, but it does have expressive eyebrows, multicolored eyes, and a speaker for a mouth. What makes it interesting, though, is the fact that it receives audio commands via the headphones it wears. You can see [Canny] in action in the video below.

The headphones couple audio tones to [Canny’s] microphone using AFSK (audio frequency shift keying). [Canny] uses an opamp to bring the microphone level up and then uses a 567 PLL IC to decode the audio tones. [Adam] selected two clever frequencies for the mark and space (12345 Hz and 9876 Hz). In addition to being numerically entertaining, the frequencies are far enough apart to be easy to detect, pass through the headphones with no problem, and are not harmonically related.

The 567 IC detects only one of the tones. Ignoring one tone is not always great for noise rejection, but for this use should be more than adequate and cuts the parts count down. To avoid false commands, the data contains markers, lengths, and checksums. The 567 feeds the Arduino, which handles all the robot control.

How do you create the sounds that go to the headphones? You use a Web page. Of course, you could generate the low baud rate tones in other ways, too. AFSK modems are common in Ham radio circles, and there are certainly plenty of modem designs. Then again, there is something pleasing about the simplicity of this circuit. The appeal of [Canny] doesn’t hurt any, either.