07. Motor Control

We use a stepper motor that moves in series of steps, and digitally geared. It is controlled by 4 magnetic coils and 6 magnets mounted in the shaft. It is controlled by giving current to the coils. It creates a magnetic field and attracts the magnets, so the motor rotates. Current control is the key attribute of stepper motor control. It has two types; unipolar and bipolar (HBridge). Bipolar has twice the magnetic filed strength, so twice the torque. But it has 4 NFET transistors. Uniploar has only two NFET transistors, and has less torque.

A stepper motoro control circuit A stepper motor control circuit consist of an ATtiny 15, 4 mosfet switches, an external DC voltage, a regulator, some resistors, a capacitor, a zener diode, and a header for serial connection.

Make sure the power gets dissipated in motor, not in the circuit.

In addition to the stepper motor, we have four MOSFET switches, ATtiny15L microcontroller, two 10k resistors, a 10 ohm resistor, a capacitor, a regulator, a zener diode, a header for the motor, and a DC input.

Micro stepping: steps smaller then a step, it is for synchronizing the microtime of microcontroller and the motor response.

A stepper motor A stepper motor. The cables coming out of the motor are usually standart. The Red and the green are supply voltages, the others are logic inputs.