DM163029 Microchip Technology, DM163029 Datasheet - Page 35

• Manufacturer Part Number: DM163029
• Description: BOARD PICDEM FOR MECHATRONICS
• Manufacturer: Microchip Technology

Specifications of DM163029

• Main Purpose: Power Management, Motor Control
• Embedded: *
• Utilized Ic / Part: *
• Primary Attributes: *
• Secondary Attributes: *
• Processor To Be Evaluated: PIC16F917
• Interface Type: RS-232
• Silicon Manufacturer: Microchip
• Silicon Core Number: DM163029
• Silicon Family Name: PICDEM
• Kit Contents: PICDEM Mechatronics Board, MCU Samples, Software And Cables
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

© 2006 Microchip Technology Inc.
FIGURE 2-11:
Instructions
Use POT1 to adjust the speed of the motor. Turn the potentiometer counter-clockwise
to reduce speed; turn it clockwise to increase motor speed. Multiply the LCD display by
1000 to obtain speed in RPM.
Discussion
With the CCP module operating with 8 bits of resolution, the module can output a PWM
signal at a frequency of 31.2 kHz. This is sufficiently high frequency that motor whine
is outside of the audible frequency for humans. This is especially important in applica-
tions where the motor may turn at slow speeds.
Using an optical sensor to gather feedback from a motor is an integral part of many
mechatronic systems. Some systems require a constant speed over varying loads. An
optical encoder is similar to the optical interrupter circuit used in this project. The
difference is that an optical encoder uses more than one optical sensor (as many as
four) to deduce speed and shaft position.
Note:
10 kΩ
470 Ω
POT1
D12
R20
V
V
DD
DD
The optical interrupter circuit is susceptible to interference from outside
infrared light sources (i.e., incandescent lights, sunlight, etc.). It may be
necessary to cover the optical sensor to obtain an accurate reading.
20 kΩ
1 kΩ
R11
R10
Q6
V
DD
PROJECT 5: SCHEMATIC
470 Ω
R22
V
C26
1000 pF
DD
11/32
12/31
24
2
AN0
V
RC5
V
DD
SS
PIC16F917
COM
CCP2 21
SEG
RD7 30
Simplified circuit shows
equivalent functionality
X
X
Example Projects
Segment pins
Common pins
10 kΩ
10 kΩ
VIM-332-DP
LCD1
U11:B
U10:A
Motor
V
DS51557C-page 31
DD