NXP Semiconductors
KTFRDM34933EVBUG
FRDM-34933EVB evaluation board
KTFRDM34933EVBUG
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User guide
Rev. 1.0 — 15 March 2017
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of the linked TimerUnit_LDD component. By default the Counter frequency is set
automatically by LVHBridge component. In some cases the frequency value does
not have to be set appropriately (user wants to set a different value or an error has
occurred). For more information see
Section 6.5.5 "Stepper motor speed"
.
•
Motor Control Mode allows you to select the step mode. Selecting full-step and micro-
step mode allows you to switch between full-stepping and micro-stepping in C code.
–
Full-step configuration contains speed and acceleration settings. Code for the
acceleration and deceleration ramp is generated when the Acceleration property
is set to a value greater than zero. Note that acceleration is always the same as
deceleration. The acceleration setting is 400, as shown in
Figure 10
.
– Desired motor speed is set to 100 full-steps per second. This value is defined by
the speed property in Processor Expert GUI and can be changed in C code.
– Acceleration and deceleration is set to 400 full-steps per second. This value is
defined by the Acceleration property. Note that the motor reaches the speed in
0.25 second
2
(desired_speed / acceleration = 100 / 400 = 0.25).
–
Micro-step configuration settings are similar to those of the full-step configuration.
PWM frequency is the frequency of the micro-step PWM signal. Micro-step per step
is the number of micro-steps per one full-step.
6.5.5 Stepper motor speed
The LVHBridge component defines the stepper motor’s minimum and maximum speed.
These limit values are used by the component methods. Minimum speed in full-step
and micro-step modes is one step per second. Maximum speed is 5000 steps per
second. There is a specific case when minimum full-step speed is affected by timer input
frequency. In this case the Primary Timer Device property must use FTM timer values
(FTM0_CNT, or FTM1_CNT). The Secondary Timer property must be set to Disabled.
The Stepper Motor Output Control property must be set to PWM.
Figure 11
illustrates this
configuration.