DM163029 Microchip Technology, DM163029 Datasheet - Page 36

• 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

PICDEM
DS51557C-page 32
TM
2.3.6
Project 5 uses an optical encoder to provide motor speed feedback. In this project,
another form of speed measurement will be explored, Back Electromotive Force (Back
EMF). You may be aware that a Brushed DC motor, when turned by hand, will produce
voltage at its leads, becoming a generator. When a Brushed DC motor is being driven,
and then the drive voltage is removed for a brief amount of time, the voltage generated
by the inertia of the motor will be proportional to its speed. This voltage is the Back EMF.
Objectives
1. Effectively read Back EMF using the on-board Analog-to-Digital Converter.
2. Interpret the Back EMF into a speed for the motor.
Applicable Technical Documents
Low-Cost Bidirectional Brushed DC Motor Control Using the PIC16F684 Application
Note, AN893 (DS00893)
Jumper Configuration
• RD7 (J10) to P1 (J1)
• CCP2 (J10) to N2 (J1)
• AN0 (J13) to POT1 (J4)
• AN1 (J13) to BACK EMF (J16)
• Attach the motor leads to DRIVE1 (P9) and DRIVE2 (P10).
• J2 and J3 should be unpopulated.
• Connect the right and center pins of JP8 using a shunt.
Mechatronics Demo Board User’s Guide
Project 6: Brushed DC Speed Control with Back EMF Feedback
© 2006 Microchip Technology Inc.