Designed by collinsemasi | Shared under CC BY 4.0

Original project on Flux: https://www.flux.ai/collinsemasi/avocaudio-a-tinyml-community-board-v1~1l

WHAT IS THIS PROJECT ABOUT?

AvocAudio is a compact tinyML community board designed by collinsemasi for large-scale audio data collection. It is built around the Raspberry Pi RP2040 microcontroller and uses a LoRa-E5 LoRaWAN transceiver module for connectivity. An SD card slot stores data locally, and the board runs from solar power or a lithium-ion battery, so it can be left outdoors and keep collecting.

Contributors listed on Flux include jharwinbarrozo and kerry. The design has been well received by the community, with about ten stars and more than a dozen forks.

WHY A BOARD LIKE THIS?

Tiny machine learning, or tinyML, means running machine learning models on very small, low-power devices. Training those models needs good data, and for audio applications such as keyword spotting or environmental sound classification, that means recording real sound in real places. This board is made for that job. It records audio from an on-board digital microphone, logs temperature and humidity readings alongside it, and stores everything on an SD card, while LoRaWAN lets it send status and small packets of data over long distances without WiFi.

Because it is solar-capable, it suits remote and long-running deployments, such as field research and ecological or environmental monitoring, where mains power and network access are not available.

HARDWARE DESIGN

Microcontroller: Raspberry Pi RP2040, with an external flash memory

Connectivity: LoRa-E5 LoRaWAN transceiver module (STM32WLE5JC), with an IPEX antenna connector

Audio: digital MEMS microphone

Environmental sensing: temperature and humidity sensor interface

Storage: microSD card slot

Power: lithium-ion battery connector, solar input terminal, Li-ion charger and regulation circuitry

User interface: buttons and a user LED

Operating voltage: 3.3 V

Board construction: four-layer (top, two inner layers, bottom)

STATUS

The project properties note that some connector wiring was still pending when this version was published, so please check the schematic and layout carefully before ordering. A newer revision of the board, v3 Rev 1, is also available on Flux: https://www.flux.ai/collinsemasi/avocaudio-a-tinyml-community-board-v3-rev-1~xt

MANUFACTURING FILES

The project is published ready for fabrication and assembly. It includes a complete Gerber set covering top, bottom and both inner copper layers, solder mask, solder paste, silkscreen and board outline, together with an Excellon drill file, an IPC-D-356 electrical test netlist and a pick-and-place CSV for automated assembly. Bills of materials are provided in formats prepared for several manufacturers, including a version optimised for PCBWay.

CREDITS AND LICENCE

Designed by collinsemasi (Flux), with contributors listed on Flux including jharwinbarrozo and kerry. The design is released under the Creative Commons Attribution 4.0 International licence (CC BY 4.0): https://creativecommons.org/licenses/by/4.0/

All design work and credit belong to the original creators. Please visit the original Flux project, explore the design in full, and show the creators some support.