# Speech Recognition and Synthesis in Less Than 500 KB

An open-source voice interface toolkit for microcontrollers.

- **Source:** [Hacker News (news.ycombinator.com)](https://brifing.si/source/13c923cd-6d99-442b-9b8b-1181f4d8cd91)
- **Published:** 2026-07-14
- **Topic:** [Data & AI](https://brifing.si/c/data-ai)
- **Original article:** <https://github.com/moonshine-ai/moonshine/tree/main/micro>
- **On Brifing:** https://brifing.si/s/f8ba3ed1-f6e2-4b95-884d-40a9b6bf5c40

## What is Moonshine Micro?

Moonshine Micro is an open-source AI toolkit designed for embedded system processors like microcontrollers and DSPs. It enables real-time voice interfaces on low-cost platforms such as the Raspberry Pi RP2350, which retails for just 80 cents. This makes advanced voice technology accessible for resource-constrained systems.

## Technical Specifications

Moonshine Micro offers voice activity detection (VAD), command recognition, and neural speech synthesis (TTS). It can run with as little as 470 KB of RAM. The optimized flash and SRAM usage, along with detailed memory budgeting for the RP2350 demo, make it ideal for low-resource environments.

## Performance Details

The toolkit requires ~25 MMAC/s for VAD, ~36 MMAC/s for STT, and ~65 MMAC/s for TTS. Total memory usage is ~3.6 MiB flash and ~468 KiB SRAM. This performance, combined with low power consumption, provides an excellent solution for embedded systems.

## Use Cases

Moonshine Micro can be used in voice-controlled devices, smart home systems, and industrial automation. It is particularly suitable for managing complex tasks like wifi setup via voice commands. The VAD, STT, and TTS libraries can also be used independently.

## Licensing and Commercial Use

The code is released under the permissive MIT License, making it suitable for commercial applications. The TensorFlow Lite Micro library provides the neural computation infrastructure. All components, except third-party code, are open-source with detailed licensing information available.

## Why It Matters

Moonshine Micro enables AI-based voice interfaces on low-cost, low-resource systems. This paves the way for next-generation applications in IoT and embedded systems, significantly enhancing user experience. Its open-source nature also facilitates widespread adoption.

## Sources covering this story

- https://github.com/moonshine-ai/moonshine/tree/main/micro — 

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_Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._