The idea is to build an automatic door for the chicken coop. The door is equipped with a photo-resistor and when the sun rise, the MCU is triggered and drive a step motor to open the door. And on the sun fall, the MCU is triggered again to close it.
First of all we add to write some Arduino code to setup a step motor controller. This code will be executed on an Arduino nano board.
The STM32F429 card communicate with the Arduino nano board via UART to start/stop the motor. It also communicate the direction of the rotation.