Very simple setup to control my EC fan.
The EPS8266 uses PWM to send out 0-10V to the fan's input.
It first connects to a wifi network and the uses MQTT for input/output.
Components:
https://opencircuit.shop/product/pwm-to-analog-0-10v-converter-module
https://www.wemos.cc/en/latest/d1/d1_mini.html
https://www.amazon.com/LM2577-Booster-Module-Supply-Adjustable/dp/B07LHCT4MB
It does seem that the 0-10V converter only outputs 9.34V so it's not exactly ideal.
But for my type of application it doesn't really matter that much.