Planet Arduino

You’ve probably heard that there isn’t any sound in space. That’s because sound is vibration traveling through a medium, like air or wood, and space is a mostly empty vacuum. The frequency of the vibration in a medium is the pitch of the sound and the amplitude is the volume. If you want a way to visualize the frequencies of the sounds around you, Vaclav Krejci (upir on YouTube) designed an Arduino-based audio analyzer that you can build.

Like the visualizer of the equalizer on an old stereo receiver, this displays the levels of several frequency bands within the audio it monitors. In this case, that audio is the sound around the device collected by an onboard microphone. It shows the levels for seven different frequencies: 63Hz, 160Hz, 400Hz, 1kHz, 2.5kHz, 6.3kHz, and 16kHz. Most devices like this use LEDs to show the levels, but this shows them on a OLED screen instead and that allows for more flexibility.

That OLED screen connects to an Arduino Uno Rev3 board, which uses a pair of DFRobot modules to work with the audio. The first is an analog mic board that performs amplification to boost the audio signal up to something usable. The second is the AudioAnalyzer board that breaks that audio signal down into seven frequencies. Krejci’s code is straightforward and simply displays seven bar graphs corresponding to the amplitude numbers provided by the AudioAnalyzer board.

Use this in space and it should show all zeroes. But use it here on Earth and it will help you analyze the sound around you.

The post Analyze the ambient sound around you with this Arduino setup appeared first on Arduino Blog.

We live in a world in which nearly any kind of gadget or tool you can imagine is just a few clicks away. In many respects, this has helped fuel the maker culture over the last decade or so; now that people aren’t limited to the hardware that’s available locally, they’re able to create bigger and better things than ever before. But it can also have a detrimental effect. One has to question, for instance, why they should go through the trouble of building something themselves when they could buy it, often for less than the cost of the individual components.

The critic could argue that many of the projects that grace the pages of Hackaday could be supplanted with commercially available counterparts. We don’t deny it. But the difference between buying a turn-key product and building an alternative yourself is that you can make it exactly how you want it. That is precisely why [Sam Izdat] created this truly one of a kind microphone preamplifier. Could he have bought one online for cheaper? Probably. Could he have saved himself an immense amount of time and effort? Undoubtedly. Do we care? Not in the slightest.

The amplifier is based on the Texas Instruments INA217 chip, with an Arduino Nano and 128×64 OLED display providing the visualization. [Sam] was able to find a bare PCB for a typical INA217 implementation on eBay for a few bucks (see what we mean?), which helped get him started and allowed him to spend more time on the software side of things. His visualization code offers a number of interesting display modes, uses Fast Hartley Transforms, and very nearly maxes out the Arduino.

But perhaps no element of this build is as unique as the case. The rationale behind the design is that [Sam] wanted to compartmentalize each section of the device (power supply, amplifier, visualization) to avoid any interference. The cylindrical shapes were an issue of practicality: the compartments were constructed by using a hole saw to make wooden discs, which were then glued together and hollowed out. The case was stained and coated with polyurethane, but due to some slightly overzealous use of glue and fillers, the coloring isn’t uniform. This gives the final piece a somewhat weathered look, in sharp contrast to the decidedly high-tech looking display.

Overall, this build reminds us of the modular 3D printed amplifier we saw earlier in the year combined with these speaker-integrated Arduino VU meters.