It's based on the ATmega 328 version: https://github.com/TheDIYGuy999/Rc_Engine_Sound and on bitlunis Halloween example: https://github.com/bitluni/MotionPumpkin ...

Functions to go a specified distance: Driving speed PWM (2.0 V) is the PWM value to use for driving a fixed distance. If it is set higher than RAMP_VALUE_OFFSET_SPEED_PWM (2.3 V), the software ...