Full steps and half steps: resolution, commands and speed

Separate three quantities before comparing modes

An ideal 200-full-step motor divides one revolution into 200 positions, or 1.8° per step. Half-stepping interleaves positions for 400 commands per revolution, or 0.9° per command. This is commanded resolution, not guaranteed mechanical accuracy under load.

Command rate specifies how many advances are requested each second. At the same rate, half-stepping moves through less angle per advance. Resolution and speed therefore need separate comparisons.

What happens at 100 commands per second

The bipolar full-step sequence has four electrical states; half-stepping has eight. A coil cycle repeats many times per mechanical revolution. Eight table rows do not make a 200-step motor an eight-step motor.

What you can conclude and what still needs measuring

At equal current magnitude per phase, the half-step example alternates one and two active coils. Resulting field magnitude is not constant. Some drivers regulate current to change this behavior; the lab shows the basic uncompensated sequence.

The rpm calculation assumes the rotor follows every command. Acceleration, resonance, load torque and missed steps are not modeled. Requesting 800 commands/s does not show that a particular assembly can start instantly at that rate.

Coils need a suitable power stage and current limiting for the motor and driver. The table is a logical description of currents, not a circuit for connecting coils directly to a board’s pins.

Compare one variable at a time

1. In the experiment, keep 100 commands/s and switch modes. Record angle per command and rpm.
2. In half-step mode, increase to 200 commands/s and observe what is restored.
3. In the full tool, step forward and backward. Distinguish the electrical indicator from mechanical displacement.