Spectrum Painting on 2.4 GHz

Give a software-defined radio (SDR) platform to a few thousand geeks, and it’s pretty predictable what will happen: hackers gotta hack. We’re only surprised that it’s happening so soon. Spectrum Painter is one of the first cool hacks to come out of the rad1o badge given out at the CCCamp 2015. It makes it dead-simple to send images in Hellschreiber mode on a few different SDR hardware platforms.

What we especially like about the project is its simplicity. Don’t get us wrong, we’re tremendous fans of GNURadio and the GNURadio Companion software radio hacking environment. But if you just want to do something simple, like send a picture of a smiley-face, the all-capable GNURadio suite is overkill.

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Waterfall Swing Set

[Doped Boron] wrote in to tell us about this waterfall swing by [Dash 7]. Naturally, we had no idea what a “waterfall swing” was. Shown at the World Maker Faire in 2011, the device is a swing set capable of accommodating one or two people using it at a time. What makes it interesting, is that water comes out of the top support bar, forming a wall of water for the riders to pass through. This wall is then broken when the swing user flies through it making for a dry experience.

According to the article, 273 solenoid valves are used to control the wall of water. These solenoids are controlled by a computer with sensors that detect where the riders are in the air and what speed they are going. As with most good hacks, it may not serve a “grown-up” purpose, but a set would definitely make a trip to the park more interesting!

Be sure to check out the videos after the break. The first shows the swing in its traditional role, but the second may be even more interesting, showing full control of the swing solenoids for water writing! Continue reading “Waterfall Swing Set”

Waterfall signal visualizer from Arduino and cellphone LCD

[Leigh] is a HAM operator (you may know him as wa5znu). He is familiar with a signal visualization tool called a waterfall which plots signal strength and frequency over time. He wanted to build his own waterfall and ended up with this Arduino-based version which he calls Cascata. Cascata means waterfall in Italian which meshes nicely with Arduino’s country of origin

The display he chose is a Nokia LCD shield from SparkFun. It’s easy to plug in and there were already libraries available to drive the display. The audio input just connects to a headphone plug (you can just make it out at the bottom right in the image above) using some electrical tape. A free-formed resistor divider ensures that the signal is within a measurable range. [Leigh] found that signal noise was a bit of a problem but was able to improve his results by adding a capacitor to the Arduino headers between the VREF and GND pins.

See it in action after the break.

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