The Windows Application
Figure 13. Step Control
To move the motor a number of steps and then stop, fill the # of Steps text box with a decimal number
from 0 to 65535 and the motor will move that number of steps at the speed specified on the PPS text box.
No acceleration or deceleration takes place under this function.
3.5.3
Stepper Speed Calculator
In order to easily translate steps per second to actual angular velocity, a simple calculator is provided. The
calculator extracts step resolution information from the Mode x pins values and STEP frequency from the
PPS text box. The user must then provide number of steps per resolution the motor has been
manufactured to achieve. For example, a 1.8 degrees stepper motor would have 200 steps per revolution,
and so on.
By pressing the Compute button, the calculator reports the revolutions per second and revolutions per
minute parameters. For example, on the picture below, the stepping rate was set to 4000 steps per
second. While microstepping with 4 degrees of microstepping, a motor with 200 steps per revolution
should be moving at 5 revolutions per second or 300 revolutions per minute.
Figure 14. Stepper Speed Calculator
11
SLVU361B – April 2010 – Revised October 2013
CPG004_DRV88xx Evaluation Modules
Copyright © 2010–2013, Texas Instruments Incorporated