DEMO9S08QD4 Freescale Semiconductor, DEMO9S08QD4 Datasheet - Page 5

• 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

Controlling the Stepper Based on an Input Signal (PWM)
Figure 5. Stepper Motor with Gauge
To define how many steps complete a cycle, establish how many positions are available. In this example
there are 100 different positions. In case of a temperature sensor, this could be from 0 °C to 100 °C. In case
of speed this could be 0 kph to 100 kph. This means that 1% of the duty cycle is associated as one step of
the stepper motor, one centigrade or one kph. See Figure 5 and Figure 6.
Figure 6. Stepper Motor Gauges at Different Duty Cycles
The position of the gauge depends on the duty cycle of the PWM signal. There are different ways to
translate duty cycles to steps. For example, the average voltage can be measured during one period of time
using the ADC of the microcontroller. This document explains how to use the timer/pulse width modulator
(TPM) module.
Driving a Stepper Motor Based on the MC9S08QD4 and Other 8-bit Families, Rev. 0
Freescale Semiconductor
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