Handheld Fan Prototype - with HomeKit Integration

This model was inspired by the original model, but shared almost none of the original components. I have tested a few design of the fan blades and found the centrifugal type provides the best static pressure thus the best airflow. The fan supports Homekit integration with a web interface, along with an optional rotary encoder that allows you to turn it on / off and control speed. Here are the bill of additional materials:6402 motor (https://www.amazon.com/dp/B00UYTFWI2) that's compact enough to fit inside.DRV8871 DC motor driver (https://www.amazon.com/dp/B0DN66P9XW)Rotary encoder / Switch (https://www.keyestudio.com/products/free-shipping-keyestudio-rotary-rotation-encoder-module-for-arduino) - this is optional if you want manual controlRaspberry Pi Pico W (or Raspberry Pi Pico 2 W, or Raspberry Pi Pico)Buck converter to power the Pi7.2V (twin-pack) 18650 batteryHere is the code that you'll need to program the Pi: sqexpress/pico_fan: This is for a desk fan that's runs on R