DEMO9S08QD4 Freescale Semiconductor, DEMO9S08QD4 Datasheet - Page 2

• Manufacturer Part Number: DEMO9S08QD4
• Description: BOARD DEMO FOR MC9S08QD FAMILY
• Manufacturer: Freescale Semiconductor
• Type: MCUr

Specifications of DEMO9S08QD4

• Contents: Board, Cable, CD
• Processor To Be Evaluated: MC9S08QD
• Data Bus Width: 8 bit
• Interface Type: USB
• Silicon Manufacturer: Freescale
• Core Architecture: HCS08
• Core Sub-architecture: HCS08
• Silicon Core Number: MC9S08
• Silicon Family Name: S08QD
• Rohs Compliant: Yes
• For Use With/related Products: MC9S08QD2, MC9S08QD4
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Stepper Motor Management
Available with this document is the software for this application note, AN3602SW.zip.
Figure 1. DEMO9S08QD4 Evaluation Board
Section 5, “How to Port the Code and Use Other
Devices,” explains the structure of the code and how it
can be ported to other similar MCUs, for example the MC9S08QG8 and the MC9S08SG8. The code
described in this application note has been developed based on the DEMO9S08QD4 evaluation board
shown in
Figure
1.
2
Stepper Motor Management
A stepper motor is a small brushless synchronous electric motor that can divide a full rotation into a large
number of steps. If this motor is electronically commutated, the motor's position can be controlled with
precision without any feedback mechanism.
Steppers exhibit more vibration than other motor types. The discrete step tends to snap the rotor from one
position to another. This vibration can cause the motor to lose torque at some speeds. The effect can be
mitigated by accelerating quickly through the problem speed range, physically dampening the system, or
using a micro-stepping driver. Motors with a greater number of phases have a smoother operation than
those with fewer phases.
There are two basic arrangements for the electromagnetic coils: bipolar and unipolar. This application note
focuses on a bipolar motor.
A bipolar motor is built with two different coils named in this document as coil A and coil B. This is why
this stepper motor has four different wires. Bipolar stepper motors operate differently from traditional DC
motors. Stepper motors have multiple toothed electromagnets arranged around a central metal gear. The
Driving a Stepper Motor Based on the MC9S08QD4 and Other 8-bit Families, Rev. 0
2
Freescale Semiconductor