I started with motor driver circuit. As the steering motor is so small and cannot handle too much current I needed to find a stepper driver with sense input. Second neccessary character is low voltage operation. 2.7V-15V is suitable for this project.

Second circuit is about USB input for charging and programming

To be on the safe side there needs to be a USB to serial converter: 

For MCU I chose ESP32S2 MINI  as it has enough I/O for this project

Power is handled by main switch 

And a TP4056 is chosen for charger 

3.3V linear regulator for ESP32

And simple battery level measuring input

Missing are some LEDs and buttons. To make some noise I chose this piezo buzzer. Porbably I should make some calckulations on the drive power for that.