What is m5mic?

m5mic turns an M5StickS3, a small, credit-card-sized microcontroller device made by M5Stack, into a fully functional microphone you can use with your computer. It does this through firmware written in Rust that runs directly on the hardware, paired with a companion menu-bar app for macOS. There are two ways to use it. The first is USB: plug the StickS3 into your Mac or PC with a cable, and it shows up as a standard USB Audio Class microphone called "m5mic", no drivers, no Wi-Fi, no extra software needed. The second is wireless: the device streams raw audio (in pcm_s16le format, which is uncompressed audio data) over a WebSocket connection to your computer. On macOS, the menu-bar app receives that stream and creates a virtual microphone input through a custom CoreAudio driver, so any app that reads microphone input sees m5mic as a regular audio source. Wireless discovery is handled automatically: the receiver app advertises itself on your local network using mDNS (a protocol that lets devices find each other by name without a central server), with a fallback to UDP broadcast so the firmware can locate it even without mDNS support. The menu-bar app shows live status, whether the device is streaming, whether the USB connection is active, and driver health, and lets you switch between wireless and USB modes. A standalone command-line receiver is also included for developers who want to capture raw WAV recordings for debugging. The firmware itself is built using the ESP Rust toolchain targeting the StickS3's processor. Wi-Fi credentials and power settings are saved on the device in NVS (non-volatile storage), so the setup survives reboots.