ANAVI Dev Mic is a compact, affordable, exceptionally adaptable open-source microphone designed with machine learning in mind. At its core are the Seeed Studio XIAO RP2040 module and an omnidirectional digital microphone that work together to ensure high-quality sound capture and processing.

For artificial intelligence (AI) and machine learning (ML) voice applications, reliable audio capture hinges on the clarity of the microphone. Despite their wide availability, affordable USB microphones can face certain limitations, such as a tendency to pick up excessive environmental noise, inflexible hardware, and proprietary firmware that cannot be updated or improved.

ANAVI Dev Mic offers three key advantages:

1. Transparency: As open hardware, ANAVI Dev Mic facilitates accessibility, education, and the right to repair.
2. Extensibility: With nine GPIO pins on the PCB, ANAVI Dev Mic is capable of extensive hardware expansion. You can integrate additional buttons, LEDs, and sensors to enhance its functionality and adapt it for various applications.
3. Customizability: Thanks to its open-source firmware, ANAVI can be tailored to your specific needs and preferences.

Fine-Tune Your Microphone

With its USB Type-C connector, ANAVI Dev Mic seamlessly connects to any PC or single-board computer (SBC) to ensure plug-and-play integration.

You can flash your own firmware to customize Dev Mic for specific applications or use its I/O pins to expand its functionality by attaching additional components such as LED indicators, a mute switch, and other buttons.

Whether you’re conducting research, developing a voice-recognition system, or creating interactive experiences, ANAVI Dev Mic is the ideal tool for your projects.

Features & Specifications

• Module: Seeed Studio XIAO RP2040
• Microcontroller: Raspberry Pi RP2040
• Microphone: STMicroelectronics MP23DB01HP PDM Micro Electro-Mechanical System (MEMS) omnidirectional digital mic
• Connectivity: USB Type-C
• Firmware: Open source based on Raspberry Pi Pico C/C++ SDK
• Sample Rate: 16 kHz
• Compatibility: Windows, macOS, and Linux support
• Dimensions: 35.0 x 34.5 mm (1.38 x 1.36 inches)

ANAVI Dev Mic is a digital USB microphone based on MEMS technology, featuring a Raspberry Pi RP2040 microcontroller and an STMicroelectronics MP23DB01HP microphone. RP2040 marks Raspberry Pi’s debut into the microcontroller realm, boasting dual ARM Cortex-M0+ processors clocked at 133MHz and 264kB of on-chip SRAM spread across six independent banks. Originally launched with the Raspberry Pi Pico development board, RP2040 is used for this project in the more compactSeeed Studio XIAO module with a USB-C connector. A standout feature of the RP2040 microcontroller is its programmable inputs/outputs (PIO), which allows for the creation of additional or new hardware interfaces such as PDM microphone integration in the Microphone Library for Pico. PDM (Pulse-Density Modulation) represents an analog signal as a binary digital signal. Pulse-width modulation (PWM) is a specialized form of PDM, featuring a fixed switching frequency. PDM, on the other hand, offers higher bandwidth and superior characteristics due to its variable switching frequency.

Proudly Open Source

ANAVI Dev Mic is an entirely open-source project that combines open-source hardware with free and open-source software. The PCB and its acrylic enclosure were created in KiCad. The firmware is based on the open-source Microphone Library for Pico, which is available on GitHub under the Apache-2.0 License, and the Raspberry Pi Pico C/C++ SDK.

Open-source hardware empowers individuals to control their technology, enabling them to repair, reuse, and maintain their devices for years to come. Join the open-source movement to drive technological innovation and reduce e-waste.

Manufacturing Plan

Demonstrating our commitment to local manufacturing, all units are prepared and packaged in Plovdiv, Bulgaria. To maintain consistently high quality, the printed circuit boards (PCBs) of the ANAVI Dev Mic feature a black solder mask and a gold surface finish. The key component is the Seeed Studio XIAO RP2040, a compact module with a powerful Raspberry Pi RP2040 microcontroller and an array of rich peripherals. Each unit is carefully flashed and tested with the open-source firmware written in the C programming language.

Fulfillment & Logistics

All ANAVI Dev Mic kits will be shipped to our backers using Crowd Supply’s fulfillment services.

Once manufacturing is complete, we’ll make a bulk shipment to Crowd Supply, and from there, the packages will be shipped out to our backers. For more details, please have a look at this guide to ordering, paying, and shipping.

We’re committed to sustainability so all units are packaged inside eco-friendly, recyclable cardboard boxes.

Risks & Challenges

We have already manufactured and assembled a small batch of ANAVI Dev Mic printed circuit boards and acrylic enclosures to ensure that everything works correctly and we are ready for mass production!

We have a proven track record of delivering projects on time, and often ahead of schedule, as demonstrated by our previous crowdfunding campaigns. Our journey began in 2017 with the ANAVI Infrared pHAT add-on board for Raspberry Pi, and most recently, we successfully delivered the ANAVI Handle USB adapter for the Nunchuk controller in early 2024. Over the years, we have built a trusted supply chain by partnering with small local factories in Plovdiv and the surrounding regions. To minimize manufacturing risks and guarantee timely delivery, we maintain an advance stock of all components.