The hardware itself is pretty straightforward. There is an Arduino Nano to run the speech recognition algorithm and a MAX9814 microphone amplifier to capture the voice commands.

The Arduino is emulating a mouse and keyboard on the Apple Desktop Bus using code based on the abduino by [akuker]. [Bart]’s custom software on the modern Mac captures the mouse and keyboard ...

The Arduino Nano ESP32 based color handheld console by Volos Projects is a fantastic little project that showcases the power and versatility of the Nano ESP32.

Arduino Maker Nano RP2040 “Slightly shorter than a Pico, this board has 30 pre-soldered pins, all helpfully labelled on the silkscreen.

The Raspberry Pi Pico is both faster and cheaper than the Arduino Nano, but the nano has better resources and community.