Stellaris® Stepper Motor RDK User’s Manual
November 4, 2009 17
6
GUI Main Window Buttons
Run button Enables the stepper motor for running. The stepper motor must be 
enabled before it can be used. The motor does not move immediately 
when the Run button is pressed. It only moves after the position 
control is used to set a new position.
Stop button Stops the motor. If the motor is running, the motor decelerates to a 
stop. Once the Stop button has been clicked, the Run button must be 
clicked before the motor will operate again.
Configure button Opens the Configuration window. The Configuration window is 
described in more detail in “Configuration Window” on page 18.
7
Statistics Area
DC Bus Voltage Shows the voltage supplied to the motor, as measured by the 
microcontroller.
Motor Current  Shows the peak current of the two windings, averaged together. This 
value is sampled when the windings are switched on. The current 
during the time when the windings are switched off is not measured, 
and that is not reflected in the measurement. The motor current is not 
available if PWM mode is used, and the current indicator will be 
grayed out.
Processor Usage Indicates the microcontroller CPU load by percentage. Useful for 
estimating the loading of different applications and motor control 
algorithms.
Temperature Indicates the internal temperature sensor of the microcontroller.
8
Special Indicator Area
COM Port Displays the COM port number, and status. If the indicator is shown in 
black, and displays a number for the COM port, then the serial port is 
opened. If the indicator is shown in red, and displays Err, then no 
COM port is opened. The COM port selection dialog box can be 
opened by double clicking on the COM port indicator.
Target Displays the status of the target connection. If the Target is shown in 
black, and indicates Stepper, then the program is communicating with 
the RDK via the USB/serial port. If the indicator is shown in red, then 
there was a problem communicating with the target. Communication 
with the target can be restarted by double-clicking on the Target 
indicator.
Fault Indicates that an overcurrent fault has occurred. Otherwise, the 
control is not visible. To clear the fault condition, double-click on the 
Fault indicator.
Table 2-1. Description of GUI Main Window Controls (Continued)
Item No. Name Description