An Easy Music Visualizer With The Arduino Nano

December 8, 2021 by 3 Comments

Flashing LEDs are all well and good, but they’re even better if they can sync up with ambient sounds or music. [mircemk] has built the LUMAZOID visualizer to do just that, relying on some staple maker components to do so.

The build is open-source, and designed to work with strings of 60, 120, or 180 WS2812B LEDs. An Arduino Nano is charged with running the show, capturing audio via its analog-to-digital converter. A sensitivity pot enables the input level to be set appropriately.

From there, a Fast Fourier Transform is taken, providing data on the intensity of the audio in various frequency bins. The LUMAZOID can be set up to respond to just bass or to all frequencies as a whole. This data is then used to pulse the LEDs in time with the beat.

It’s a fun project that demonstrates the basic techniques required to build an audio-reactive visualizer. We’ve seen some other great builds in this space before, too. Video after the break.

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Arduino Plays The Glasses

November 22, 2021 by 8 Comments

Have you ever been on a city street and seen a busker playing music on glasses? Each glass has a different amount of water and produces a different note when tapped. [Cyberlab] must have seen them and created an Arduino robot to play tunes on glasses. You can see the result in the video below.

If we had done this, we might have had a solenoid per glass or used some linear component like a 3D printer axis to pick different glasses. [Cyberlab] did something smarter. The glasses go in a circle and a stepper motor points at the correct glass and activates a solenoid. The result is pretty good and it is a lot simpler than any of our ideas.

If you aren’t musically inclined, you might wonder how you’d program the songs. There’s an example of taking a music box score from a website — apparently, there are lots of these — and removing any polyphony from it. The site mentioned even has an editor where you can import MIDI files and work with them to produce a music box strip that you could then convert. Then you encode each note as a number from 0 to 6.

Of course, you also have to fill your glasses with the right amount of water. A piano tuning phone app should be useful. We’ve seen this done in a linear fashion before. You can even use a single glass for many notes with a little ingenuity.

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Arduino + Ham Radio = Texting

November 19, 2021 by 12 Comments

Over on the Spectrum web site, [Dale] — a relatively new ham radio operator — talks about his system for sending text messaging over VHF radios called HamMessenger. Of course, hams send messages all the time using a variety of protocols, but [Dale] wanted a self-contained and portable unit with a keyboard, screen, and a GPS receiver. So he built one. You can find his work on GitHub.

At the heart of the project is MicroAPRS, an Arduino firmware for packet radio. Instead of using a bigger computer, he decided to dedicate another Arduino to do everything but the modem function.

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Arduino Library Makes Digital Rain Like It’s 1999

November 17, 2021 by 31 Comments

There’s going to be a new Matrix movie in theaters next month, and you know what that means: we’re about to see a whole new generation get obsessed with the franchise’s iconic “Digital Rain” effect. Thanks to modern advertisement technology, expect to see lines of glittering text pouring down the displays of everything from billboards to gas pumps pretty soon.

Doesn’t get much easier than that.

For those of us who’ve just been looking for an excuse to break out the old Matrix screensavers, you might as well get a jump on things using this handy Arduino library for the ESP8266 and ESP32. Developed by [Eric Nam], it lets you start up a digital rainstorm on displays supported by the TFT_eSPI library as easily as running digitalRainAnim.loop().

You can even install the library through the Arduino IDE, just open the Library Manager and search for “Digital Rain” to get started. You’ve still got to hook the display up to your microcontroller, but come on, [Eric] can’t do it all for you.

Looking at the examples, it seems like various aspects of the animation like color and speed can be configured by initializing the library with different values. Unfortunately we’re not seeing much in the way of documentation for this project, but by comparing the different examples, you should be able to get the high points.

While our first choice would certainly be a wall of green alphanumeric LED displays, we can’t help but be impressed with how easy this project makes it to spin up your own little slice of the Matrix on the workbench.

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NTP, Rust, And Arduino Make A Phenomenal Frequency Counter

November 17, 2021 by 28 Comments

Making a microcontroller perform as a frequency counter is a relatively straightforward task involving the measurement of the time period during which a number of pulses are counted. The maximum frequency is however limited to a fraction of the microcontroller’s clock speed and the accuracy of the resulting instrument depends on that of the clock crystal so it will hardly result in the best of frequency counters. It’s something [FrankBuss] has approached with an Arduino-based counter that offloads the timing question to a host PC, and thus claims atomic accuracy due to its clock being tied to a master source via NTP. The Rust code PC-side provides continuous readings whose accuracy increases the longer it is left counting the source. The example shown reaches 20 parts per billion after several hours reading a 1 MHz source.

It’s clear that this is hardly the most convenient of frequency counters, however we can see that it could find a use for anyone intent on monitoring the long-term stability of a source, and could even be used with some kind of feedback to discipline an RF source against the NTP clock with the use of an appropriate prescaler. Its true calling might come though not in measurement but in calibration of another instrument which can be adjusted to match its reading once it has settled down. There’s surely no cheaper way to satisfy your inner frequency standard nut.

Binaural Hearing Modeled With An Arduino

November 16, 2021 by 15 Comments

You don’t have two ears by accident. [Stoppi] has a great post about this, along with a video you can see below. (The text is in German, but that’s what translation is for.) The point to having two ears is that you receive audio information from slightly different angles and distances in each ear and your amazing brain can deduce a lot of spatial information from that data.

For the Arduino demonstration, cheap microphone boards take the place of your ears. A servo motor points to the direction of sound. This would be a good gimmick for a Halloween prop or a noise-sensitive security camera.

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Arduino Piano Tuner Is Pitch Perfect

November 10, 2021 by 16 Comments

[JanHerman] knows that tuning musical instruments is all about precision and that precision is measured in a logarithmic unit called a cent. A cheap tuner unit might be accurate to 1.5 cents which sounds good until you look at one for ten times the price and find it is accurate to 0.1 cents. So you can spend $800 for precision or $60 for something less. [Jan] decided to build something better and cheaper using a 32-bit Arduino and a DDS frequency generator chip on a breakout board.

Oddly enough, the device doesn’t have a display. Instead, it generates a precise frequency and couples it to the piano using a transducer. You tune the string to the corresponding note. The post has a lot of detail about how piano tuning works.

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