Modern microcontrollers are remarkable technological achievements that have transformed the way we approach electronics and programming. However, many projects tend to complicate their designs by incorporating multiple components. A refreshing exception to this trend is the innovative Pi Pico MIDI looper developed by [oyama]. This project exemplifies how a single microcontroller can effectively manage complex tasks without unnecessary embellishments.

The Pi Pico MIDI looper uses the PicoW variant of the microcontroller to interface with synthesizers via MIDI-BLE technology. This versatile setup can connect not only to professional music equipment but also to applications on smartphones, making it accessible for users of all skill levels and resources. The simplicity of the device is highlighted by its single control button, which is in fact the bootsel button on the Pico W. This button serves multiple functions: it allows users to select from four different drum tracks, set the tempo, and input notes for the active trackall through a straightforward interface.

The operation of the looper is elegantly simple. Users can easily create rhythms by tapping out beats on each track. Once recorded, the looper will repeat the selected rhythm indefinitely until the user presses the button again to switch tracks or make adjustments. Additionally, the device features a serial interface that provides a real-time visual display of its actions via UART or USB, ensuring that users can easily monitor what is happening as they interact with it.

For such a minimalistic build, the parts list (Bill of Materials, BOM) is incredibly succinctit consists solely of the Pi Pico W. To witness this innovative project in action, viewers can check out the demo video, which showcases the functionality and ease of use of the MIDI looper.

Given the capabilities of the analog-to-digital converter (ADC) integrated into the Pico, there is significant potential to expand this basic design. For instance, adding a speaker could transform it into a standalone one-button synthesizer, thus broadening its usability. Alternatively, introducing additional buttons could enhance its functionality, although such modifications would divert from the beautifully simple, single-item BOM that [oyama] originally intended.

Moreover, the project is fully open-source and available on GitHub under the BSD license. This encourages a collaborative spirit where users are welcome to fork the project and explore their creative ideas, building on the foundation laid by [oyama]. Its clear that the open-source nature of this looper invites enthusiasts and hobbyists to experiment and innovate further.

Interestingly, the MIDI-BLE standard has been utilized in other projects as well, including a notable hack that integrated it into a Eurorack system. For those who are captivated by synthesizers, the Pi Pico MIDI looper serves not only as a functional device but also as a source of inspiration. It highlights the possibilities available for aspiring creators who wish to design their own synthesizers from scratch without relying on microcontrollers.