Frequently Asked Questions

What is an AeroSynth Windii?

It's a groundbreaking electronic wind instrument known for its versatility and advanced features. Here are the key aspects of this innovative instrument:

  • Versatile Sound Emulation: Windii can mimic a wide range of traditional wind instruments, such as the flute, oboe, clarinet, saxophone, trumpet, and even bagpipes.

  • Breath-Free Accompaniment: It offers the option to be played without using breath for accompaniment or percussion, enhancing its usability and flexibility.

  • High Customizability: Windii is programmed in MicroPython, allowing musicians to customize the instrument to their specific needs and preferences, which sets it apart from other electronic wind instruments on the market.

  • Exceptional Expressiveness: The sound produced by Windii is exceptional, making it one of the most expressive electronic wind instruments available.

  • Portability: As a self-contained and portable device, it is convenient for musicians to use in various settings.

  • Ideal for Various Users: Suitable for professional, amateur, and student musicians, as well as techies, makers, embedded software developers, and engineers.

  • MIDI Controller: Windii also functions as an excellent MIDI controller with numerous digital and analog controllers, making it great for composers, DAW users, and DJs.

In conclusion, the AeroSynth Windii is an excellent choice for musicians and tech enthusiasts looking to explore new sounds and expand their musical capabilities due to its portability, expressiveness, and high degree of customizability.

Can I customize it?

YES. This is one of the best features of Windii. Apps are written in MicroPython. This makes Windii unique amongst any other EWI or keyboard synth available.

Besides writing your own software, you can create your own custom enclosure since all mechanical drawings are available. I've made enclosures out of walnut and gold plated keypads and it looks pretty nice. Regarding keypads, as long as they are somewhat conductive, you can go crazy with unique designs. You can even print keypads using conductive PLA.

How good is the breath sensor?

The AeroSynth breath sensor is very sensitive and accurate. It's also very fast. Every nuance of your breath or tonguing can be sensed. It even has the ability to determine what note you hum into it--an electronic kazoo (future feature).

What is that band around the mouth piece used for?

It's a carburetor and allows you to adjust the airflow and how much pressure you are most comfortable with. When fully closed, it's possible to sip like a straw which creates a negative sensor value that can be used to create some additional interesting sounds.

Can you clean the mouth piece?

Yes. The mouthpiece can be taken apart and cleaned. The plastic tubing that connects to the pressure sensor is made from medical grade silicon rubber and can be flushed out with denatured alcohol.

How much does it weigh?

Unlike other EWI devices, Windii only weighs in at under 8 oz (225g), or about 10 times less than other EWI's. No neck strap is needed. Being lightweight makes it easy to carry around and play.

Where are the sound files stored?

Internally in the Flash memory. When you attach Windii to the USB port on your PC, it will enumerate as a disk drive, just like a Flash memory stick. You have approximately 15MB of storage available for storing your wave-forms, Python scripts, text files, and other information.

Is it an open design?

YES. It is an open project meaning that the hardware design, case, and software. MicroPython and the apps are open source code. Everything is available on Github. The only part that is not open source are the special audio processing libraries which is copyrighted IP.

What synthesizer technology is used?
  • It is a stereo polyphonic synth meaning that is can play more than one voice at a time (up to four simultaneous voices)

  • It uses digital audio samples meaning that it reproduces music using recordings of actual instruments or other natural or synthetic acoustic sounds.

  • It can be used to generate waveforms such as sine waves, triangle waves, square waves, or whatever. Python then does the ADSR envelope, LFO modulation, and dynamic filtering

  • Special effects such as reverb, echo, audio equalization, and many others.

  • All synthesizer parameters are programmed using the supplied Python libraries using this API.

How large is it?

Approximately 12" (30.5 cm) long, 1.5" (3.8 cm) wide, and less than 1" (2.5 cm) thick. About the size of a recorder. Easily fits inside a backpack.

What's inside?
  • The main processor is a RP2040 dual core 133 MHz ARM M0+ 32-bit microcontroller. Can be overclocked to 250 MHz.

  • Memory 256K RAM, 16MB of Flash memory, and 4Mbit EEPROM.

  • BlueTooth LE 5 radio

  • Li-Ion battery charger

  • Addressable RGB LED (neopixel)

  • 24 touch sensors

  • Buttons to control volume, modes, and reset

  • 2D X-Y Touch Pad

  • Stereo Codec with 1W BTL speaker amplifier

  • Breath sensor

  • Headphone jack

  • 3-axis accelerometer

  • USB 3.0 for power, firmware updates, and loading audio files.

  • Expansion ports external speakers, classic MIDI, OLED display, NeoPixel LED strips, GPIO, PWM, SD Card, and many other sensors and peripherals.

  • Top and bottom panels made from clear plastic (optional colors available)

  • On/Off Slide Switch

Are there special effects?

Of course. You have reverb with adjustable parameters. You have chorusing, echo, tremolo, vibrato, pitch bend, portamento, distortion, real-time state variable filters, equalizer, spatializer, and many more. You can also adjust the global sample rate (for tuning) and a mixer allows you to adjust the "wet" and "dry" audio levels and pan of each voice. The AeroSynth API library sets up the parameters.

Can I create my own sounds?

YES. Widii uses the sfz format (similar to a soundfont). You can use a program like Polyphone to record and create sfz files and directories. Audacity can be used to edit the waveforms. When done, you save the sfz and the associated .wav files directly to the Windii Flash File System.

Who is it for?

Windii is designed for a diverse range of users, including:

  • Musicians: Whether you're a professional, amateur, or student musician, Windii offers the expressiveness and versatility to enhance musical performance and creativity.

  • Tech Enthusiasts: If you're a techie, maker, embedded software developer, engineer, software programmer, or an electronic synthesizer enthusiast, Windii serves as an excellent platform for exploring and developing new software and hardware projects.

  • Composers and DJs: With its numerous digital and analog controllers, Windii functions as an excellent MIDI controller, making it ideal for composers, digital audio workstation (DAW) users, and DJs seeking to expand their musical toolkit.

  • Students: Windii is easy to use and forgiving, making it suitable for students. It supports private practice with earbuds and offers Bluetooth and USB connectivity for integrating specialized teaching software, enhancing the learning experience.

This versatility makes Windii a valuable tool for a wide range of musical and technological applications, catering to both creative expression and educational purposes.

How does it sound?

Windii produces CD+ quality audio. But there are some things you need to know. The sound that comes out depends on several factors such as the recording quality, the sample rate, how you build the loops, and the assignment of sounds to notes. Another very important factor is your playing style. Windii is a very expressive instrument but very forgiving.

Can I purchase OEM versions?

Windii components can be purchased separately. This allows an OEM to create a vertical market product such as a specialize music teaching instrument. For those that want to do their own manufacturing, licensing is available. PCB files are in KiCad format. It is also planned to offer a small board that only performs the audio rendering for inclusion in other 3rd party instruments or projects.

What else is inside?
  • Internal 16MB memory can store dozens of instruments

  • Thousands of free sound fonts are available on the internet which can be downloaded to Windii.

  • Windii has over a 7-octave range and octaves can be split.

  • MIDI over USB and over BlueTooth

  • 1 Watt amplifier for driving an optional speaker.

  • 3.5mm audio jack for headphones or ear buds

  • Line out for connecting to amps or wireless equipment

How much does it cost?

The price of the Windii will be under $130. Did that get your attention?

Is it a kit?

Partially. You need to attach the keypads and screw the case together. No soldering is required.

Why MicroPython?

Python is arguably the world's most popular programming language. MicroPython is Python but optimized for microcontrollers and embedded systems. It's fast and so easy to use. AeroSynth has added libraries written in C to do the audio processing, sensor fusion, and other heavy lifting. Everything else is done in MicroPython.

What programming tools do I need to program MicroPython?

All you need is a serial terminal program and a text editor. Every operating system has them. When connected to a terminal, you get the familiar Python REPL prompt. No separate compiler is needed. You can use a popular IDE (integrated development environment) for development. The Windii examples use Thonny. But you can just as easily use free and open source programs like VIM, Nano, Mu, VS Code, Atom, PyCharm, Idle, Jupyter, Notepad++, Eclipse, TerraTerm, minicom, and many others.

What is the fingering?

Windii has 12 touch keypads on top and 11 touch keypads on the bottom (one is reserved for future use). The bottom keypads are controlled by your left and right thumbs. How you map the keypads to a note is entirely up to you. The mapping is stored in a Python dictionary. The demo allows you to select fingering for oboe, recorder, trumpet, or a tin whistle. You can even set the sensitivity or lock out unused touch keypads to keep things simple (great for teaching basic music). Touch keys can also be assigned for other functions such as patch changes, harmony, chords, or other controls. You have complete control what your fingers and thumbs do.

What other controls are available?

In addition to the 24 touch sensors, there is the breath sensor, a 3-axis accelerometer, a 2D XY touch pad controlled by the right thumb, and a number touch sensors and push button switches for selecting modes, volume adjustment, and other functions.

Is there wireless support?

Yes. It has BLE (Bluetooth Low Energy) in UART mode and comes standard. This can be used to interface to a smart phone or tablet, or for MIDI-over-BlueTooth. In general, BlueTooth is not recommended for sending real time audio. There is too much latency. For sending audio without latency, a wireless guitar adapter will work just fine. Many are available from Amazon for under $50. WiFi is not supported at this time.

What options and accessories are available?

In order to keep the price low, some features were made optional such as an add-on speaker, Li-Ion battery, 1/4" audio jack, wireless audio, SD Card, ARGB LED light strips (neopixel), gyroscope, bite sensor, and other goodies. These are easy to add as they are compatible with kits from major suppliers like Adafruit, SparkFun, AliExpress, Amazon, and Seeed Studio.

There is a removable panel at the rear of the instrument to accommodate custom panels to hold the accessories.

Is there a bite sensor?

A bite sensor does not come standard. Hardware is capable and I plan to support a bite sensor in a future firmware upgrade. In the meantime, there are some very interesting third party bite sensors available and Windii was designed to accommodate them.

Can I use Windii to teach me Python?

Yes. Under the hood, Windii has the sole of a Raspberry Pi Pico. In fact, you can download the RPi Pico MicroPython image directly from and it will run just fine. It will just not have the AeroSynth secret sauce, larger memory storage, or the FAT file system. Even so, you can still access the sensors and even play audio, read buttons, light up LEDs, and all the fun stuff a microcontroller learning kit has. By the way, if you've played with Lego Mindstorms, you may already know MicroPython.

Can I use Windii to teach me music?

Yes. Windii can be configured as a simplified recorder or drum which are popular for introducing music education in schools. It supports private practice with earbuds and offers Bluetooth and USB connectivity for integrating specialized teaching software, enhancing the learning experience.

Why is there an accelerometer included?

Windii can measure up, down, and tilt motions. These can be used to alter the sounds. Swing left or right to pan between left and right speakers. Swing up and down to change pitch or modulation. Or it can be used to measure taps and shaking. Lay it on your lap and trigger a set of bongo drums when you bang on the keys. Or shake it like a tambourine. Tons of potential. So I decided to include it.

Is there a display?

Windy has RGB LEDs to convey some information. But this can be extended. Windii has a Qwicc/STEMMA I2C interface so you can connect an OLED display. The alternative is to use your PC monitor or smart phone display.

Why did you choose the FAT File System?

It's the same file system used on PCs. It's also the same file system used with external disk drives and memory sticks. The alternative is LFS or Little File System. This is the standard file system that comes with MicroPython for the RPi Pico and the ESP32. It's main advantage is that it is more resistant to file corruption if power is removed during file writes. The downside is that you can't you can't see it with your OS file manager. I decided on FAT because Windii doesn't write to the file system under normal operating conditions (which is where errors can occur). There is an option to use LFS. Got you covered.

How will you promote AeroSynth?

3rd Party App. Build a user community that can contribute to Python scripts, sound fonts, accessories, and enclosures. Create iPhone or Android apps over BlueTooth. I'd love to see people playing Windii on YouTube or TikTok.

At the moment, AeroSynth is a one-man band so any help is appreciated.

How can we reach you?

Email is the best way. It may take a while to respond as I'm buried in code and hardware development.

Is there a battery?

To keep costs at a minimum, the battery is optional. A small Li-Ion battery can fit inside the case and it will keep the device powered for 12+ hours of continuous use. There is a built in Li-Ion battery charger. You can also use an external USB power supply or battery pack.

Is there an API for MicroPython?

Yes. Click here for more information.