Why use or implement a DC/stepper motor controller? Is it not possible to connect the motor directly to an MCU output pin without the driver?
A microcontroller has a very low output current. You shouldn't drive directly more than an usual indicator LED with it.
The motor draws a much higher current. Connecting directly will result in not working motor and destroying the microcontroller due to high currents.
Drivers are not used only for motors. They are used for any device that usually draws more than 50-100 mA.
Maximum current of microcontroller output (typically 10-20mA) is not enough to drive motor coil.
Connecting motor directly to microcontroller will damage microcontroller output transistor.
Easiest way to connect DC motor to microcontoller is circuit like this:
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