Dragonfly Reverb

Reverb is the name given to perhaps the most commonly used audio effect in existence. It's the echoey sound that you often hear with vocals, movie trailers, and Phil Collins' drum fills (famously gated to cut the delay). The reverb effect is nearly always added to the original clean recording when a piece of music is mixed or mastered, to help tracks sit well together or to give them a sense of three-dimensional space. Even early recordings had reverb added, which was done by physically placing a speaker and microphone in a purpose-built chamber where the sound would leave the speaker, reflect off the surfaces, and be recaptured with reverberation by the microphone. The mix engineer would then blend the affected signal (known as the wet signal) with the dry signal according to taste. Reverb was eventually coaxed from an array of springs rather than a physical space, and in the 1970s, reverb was finally produced by mathematical models running on digital signal processors. Back then, reverb effects cost thousands or tens of thousands of dollars. In the modern era, of course, we can run thousands of different reverb algorithms on a single CPU for free, although that hasn't stopped their quality being entirely subjective and often terrible.

This Dragonfly suite of reverbs, however, sounds absolutely fantastic. There are several different versions including room sounds, hall sounds (larger), plate sounds (similar to spring reverbs), and early reflections, which is limited to just the early delay components. Each plugin offers many options for equalizing the sound and increasing its density, as well as changing the size of the virtual space and the number of reflections, and they all sound wonderful. The sound itself is based on the widely used Freeverb algorithm, which favorably stacks up against even expensive commercial algorithms. Dragonfly Reverb presents this in an incredibly useful UI, with plenty of options for any open source audio processing tool.

Project Website

https://github.com/michaelwillis/dragonfly-reverb

Whether it's rock, folk, rap, or electronic, all music benefits from beautiful reverb.

Arduino builder

Arduino CLI

Long before the Raspberry Pi made diminutive open source computing popular, Arduino was doing the same for programmable microcontrollers. These truly open source boards (unlike the Rasp Pi) are still switching on lights, monitoring temperatures, and brewing beer in hundreds of thousands. They're still the platform of choice for low-power hardware solutions that don't need a CPU, on-board storage, and gigabytes of RAM. But because they're microcontrollers and not computers, they need a computer to program them, which means using the official Arduino IDE. The IDE is a great tool to learn from, but it falls short when your project outgrows the IDE. You might want to use CI to automatically build and deploy to your hardware, for example, or you might simply want to use a different code editor and trigger your own builds from the command line.

Past solutions to this included constructing a makefile to trigger the same GCC parameters used by the Arduino IDE and even subverting the arduino-builder used internally by the IDE to build your project independently. These would work initially, but they would break after the IDE updated. Fortunately, with the officially supported Arduino CLI, these hacks are no longer necessary. The arduino-cli command does everything the IDE does except provide a visual editing environment. It can download and integrate the same libraries and boards as the IDE, initiate a new sketch, and include both INO sketch files and native C files. It will also upload any resultant binary to your connected device, just like the IDE, and save your settings to a configuration file. It enables you to decouple Arduino development from the IDE and work with whatever development tools you prefer, whether that's Git or Travis CI. It's also a quicker way to develop Arduino projects, because you can use Arduino CLI from your favorite editor or IDE and quickly trigger a build just as you might with any C project.

Project Website

https://github.com/arduino/arduino-cli/

While Arduino CLI is designed to run from the command line, it's also the real powerhouse behind the Arduino Web Editor.