In the setup() function we set the pins were the LDR are connected as INPUTs and position the servo motor at 90° then wait for a 2 seconds before the code execution inside the loop(). In the loop() we ...

The Arduino code looks very basic at the moment. In practice there are some hardware quadrature encoders in the stm32l4 timer peripherals, which could be used in preference to the bit-banged ...