This MIDI synth lets you create chiptune music

---

Obscrua is an Arduino-compatible MIDI synth for creating Nintendo, C64 and Amiga-style chiptunes.

---

A chiptune refers to a genre of synthesized electronic music which was commonly found in vintage computers, consoles and arcade machines. As its name would imply, the tunes themselves were made by the sound chips within these early gaming systems and microcomputers, with an integrated waveform generator playing an integral role in the process. From Space Invaders to Gun Fight, one cannot help but love the nostalgic 8-bit beats packed inside those classic arcade cabinets.

Not to mention, who could forget the routine of pulling out their Mario Bros. cartridge, blowing into it, slipping it back in, and once successful, being welcomed by its catchy theme song? Well, those looking to spark up some nostalgia will surely get a kick out of the Obscura, an Arduino-compatible synth that allows you to create your own NES, Commodore 64 and Amiga-style chiptune music by simply connecting a MIDI device. What’s nice is that no programming is required — this monophonic MIDI synth comes preprogrammed with software that packs 16 preset patches.

If this all sounds vaguely familiar, that’s because its creators Arcano Systems recently revealed a similar MIDI chiptune synth on Kickstarter. Taking into consideration the outpouring of feedback and suggestions they received from its early backers, the team decided to rewrite the software to incorporate many of their ideas. Among those upgrades included the ability to configure the synth with the Arduino IDE using only a USB cable, eliminating the need for an AVR-ISP unit or an FTDI cable. This called for a change in hardware as well.

Unlike its predecessor that was based on an ATmega328, the new and improved Obscura is instead built around the mighty ATmega32U4 — the same MCU at the heart of the Arduino Leonardo. The latest synth has gone through a pair of hardware revisions and 12 software versions, with its latest iteration featuring a USB serial monitor mode that is activated by holding down both preset patch control buttons during boot-up. Additionally, this mode lets users view the serial data output from their MIDI machine on either a PC or Mac for debugging and hacking purposes.

“The software for the Obscura is not merely a port of the Arcano Chiptune Synth software, but was written from the ground up and uses wavetable synthesis to generate waveforms, whereas the Arcano MIDI NES Chiptune Synth generates waveforms on the fly using a series of logic statements,” the Arcano Systems crew explains.

Now, users with some programming experience will be able devise their own custom software for Obscura using the Arduino IDE. And thanks to the Arduino Leonardo’s native USB capabilities, the Obscura can be configured to appear as a USB mouse, keyboard or HID, enabling interesting possibilities of unique MIDI-PC interface applications.

Unlike many other MCU-based synthesizers which use PWM to generate weak, noisy and low-quality audio signals, the Obscura employs an auxiliary digital-to-analog converter chip with true 8-bit quantization to produce a clear, high-quality sound. The Obscura is USB-powered and doesn’t require a special wall adapter with a barrel-jack type connector. The simple user interface consists of two patch control buttons, a reset button and a 7-segment LED display. Meanwhile, audio is emitted through a standard 1/8” (3.5 mm) stereo audio jack.

So, are you ready to recreate some of your favorite 8-bit music? Head over to the synthesizer’s Kickstarter page, where Arcano Systems is currently seeking $2,000. Delivery is expected to get underway in February 2016. (And kudos to the team for a rather creative campaign video!)

This MIDI synth lets you create Nintendo-style chiptune music

---

Connect this AVR-based board to a MIDI device and make your own NES-style chiptunes.

---

Chiptunes are a type of synthesized, electronic music produced by old-school video game consoles, which became ubiquitous throughout arcades and living rooms in the ‘80s. Originally, 8-bit tunes were primarily practiced by game soundtrack composers like Rob Hubbard; yet, it wasn’t before long that tools like Karsten Obarski’s Ultimate Soundtracker were introduced, making the creation of such sounds much easier and widespread. While it mostly remained an underground genre, chiptunes certainly had their moments of moderate popularity, influencing the development of electronic dance music for years to come.

Who could forget the routine of pulling out your Mario Bros. cartridge, blowing into it, slipping it back in, and once successful, being welcomed by its catchy theme song? Well, those looking to spark up some nostalgia will surely get a kick out of the Arcano MIDI NES Chiptune Synthesizer, an AVR-based MIDI device that allows artists to make Nintendo-style chiptune music.

Each Arcano MIDI NES Chiptune Synthesizer is equipped with a 1/8” mono audio output jack, MIDI input through a standard DIN connector, a seven-segment LED waveform mode indicator, a simple two-button interface, and a preprogrammed ATmega328 for its brains. Beyond that, a six-pin AVR ISP header enables programmers to Flash the embedded MCU with their own custom software and create waveforms, envelopes, software low-frequency oscillators and PCM samples.

Unlike many other MCU-based synthesizers which use internal PWM peripherals to generate weak, scratchy audio signals, the Arcano MIDI NES Chiptune Synthesizer employs an auxiliary digital-to-analog converter chip to produce a clear, high-quality audio signal. The synth is capable of generating audio at an output rate of 44.1 KHz; however, for a more authentic chiptune sound, lower output rates are recommended.

“The hardware is capable of up to 8-bit quantization. A software bitcrusher is used to achieve the lower bit depths used in the NES. This bit-crushing effect is most evident in the Arcano NES Chiptune Synthensizer’s reproduction of the Nintendo Entertainment System’s 4-bit triangle wave channel, often used for bass lines and tom-tom drums,” its creators explain.

What’s more, the latest version of its software features additional white-noise-based percussion sounds, such as open and closed hi-hats, along with additional waveform modes that can emulate the detuned reverb effects characteristic of the music from the Mega Man series of NES games.

Ready to recreate some magical 8-bit music? Head over to the synthesizer’s Kickstarter page, where Arcano Systems successfully garnered well over its asking goal of $1,000. The first batch of units have already begun shipping.

Play real music with an ATmega328

---

Maker creates a slick six-voice AVR wavetable synth song machine.

---

What originally began as an 8-bit guitar simulator has evolved into a sophisticated six-voice music player running capable of running on an ATmega328 MCU. Maker Enrico Colombini wanted to see how far he could get with only a few resistors and capacitors, and so, selected an Arduino Uno to do the trick.

The project, which is dubbed play-v6, is an open-source synthensizer that can be programmed in plain C in Atmel Studio 6 and the Arduino IDE. Using only a tight 512-cycle CPU loop, the device is capable of producing six independent 8-bit voices with individual note volume and a play-time voice mixer, a 31.25 kHz sampling frequency oversampled at 62.5 kHz for better quality and filtering, as well as emitting both built-in music from Flash and uploaded tunes from RAM memory.

play-v6 can function as both a standalone device and via USB-Serial remote control. Beyond that, it is equipped with an adjustable tempo and up to 16 selectable instruments — each with its own waveform and ADSR envelope.

“It’s pretty sweet to get six channels of 31.25 kHz sampled 8-bit audio running on a 16MHz chip. The code underlying it works through some tricky optimization in the sample update routine (UpdateVoiceSample() in play.c if you’re reading along) and by carefully prioritizing the time critical elements,” Hackaday’s Elliot Williams writes.

Aside from simply playing embedded music, the package also includes several system-independent tools. With these, Colombini’s project can act as a compiler that converts sheet music into a compact block of binary data, an instrument generator that creates new or modifies existing sounds to emulate everything from a guitar to an accordion, and an auxiliary tool that to prompts firmware tables. The Maker notes that a music packer is required to store music into the Flash memory of the Arduino, so that it could be played without a USB-computer connection.

Additionally, a table generator is responsible for producing a note table that play-v6 employs to generate the correct pitch (frequency) for a given note. What’s more, it creates the tempo table that controls each musical setting and for how long an 1/64 interval will last. Doing the slow math as infrequently as possible lets Colombini make his timing. For instance, the pitch is updated once every two PWM samples, I/O and other auxiliary player tasks every eights samples, and the sound’s dynamic volume envelope is only recalculated every 48 samples.

“The table generator adds comments in player\tables.c indicating the pitch error for each note, assuming an accurate microcontroller clock. Unfortunately the Arduino Uno uses a cheap and imprecise ceramic resonator instead of the usual crystal. This could add a pitch error up to about 20 cents, but it does not affect the relative pitch between different notes, so unless you are a trained musician with an ‘absolute ear’ you will probably be unable to tell the difference,” the Maker concludes.

Interested? Head over to the project’s official page to learn more, or watch it in action below. (Nice find, Hackaday!)

Atmel’s ATtiny9 plays chiptunes

A chiptune – also known as chip or 8-bit music – can best be described as a synthesized electronic track produced by vintage sound chips or emulated by more modern generations of silicon.

Typically, chiptunes consist of basic waveforms, including square waves, sawtooth or triangle waves and basic percussion. These are often generated from white noise going through an ADSR envelope, low-quality PCM samples or FM synthesis.

A talented member of the demoscene known as “dojoe” managed to rig an Atmel ATtiny9 MCU to play chiptunes – using just 1KB of flash, 32 bytes of RAM and a 16 byte register file. Dubbed Noiseplug (based on a small RCA plug), the creation has 6 pins (four usable, as two are for power) and runs at 8 MHz.

Interested in learning more? The source info is available on GitHub here, while additional data on Atmel’s ATtiny9 MCU can be found here.