What is stackchan-pet-fw?

This is firmware for Stack-chan, a small desktop robot built on the M5Stack CoreS3, a compact hardware module with a screen, microphone, speaker, camera, and servo connections. The firmware gives the robot a pet-like personality, complete with an affection system that changes how it looks and acts depending on how you interact with it. The robot displays animated faces loaded from image files stored on the device. Different face expressions correspond to different states: idle, listening, speaking, blinking, reacting to being petted through the touch screen, or shaking when the device is physically moved. The affection level is tracked persistently on the device and shifts between tiers, normal, guarded, and attached, each with its own set of face images, making the robot feel more responsive over time. Beyond the screen and face animations, the firmware handles servo motors for physical movement, microphone input, and speaker output streamed as audio. The device connects to your local Wi-Fi network, or creates its own hotspot for direct connection, and exposes HTTP and WebSocket endpoints so external software can control it remotely. One WebSocket channel carries text commands in JSON format, another carries raw audio data for two way voice communication. You would use this if you are building your own Stack-chan robot and want firmware that gives it a personality beyond simple demos, specifically the pet affection mechanics, animated face states, and the network interface for external control. The project is built using PlatformIO, a development environment for embedded hardware, and the exact face image files need to be prepared and copied onto the device yourself since they are not included in the repository for licensing reasons. The full README is longer than what was shown.