Microcontroller Applications

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Microcontroller Applications

• ELEC 330
• Digital Systems Engineering
• Dr. Ron Hayne
• Images Courtesy of Ramesh Gaonkar and Delmar
  Learning

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Embedded System

• Typical analog/digital system
• Transducer
• Converts non-electrical signals into electrical
  signals
• A/D converter
• Converts analog signals into digital signals
• Digital processor
• Processes digital data
• D/A converter
• Converts digital signals into equivalent analog
  signals
• Transducer
• Converts electrical signals into non-electrical
  signals

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PIC18 A/D Converter
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Pulse Width Modulation

• Duty Cycle
• Percentage ratio of on time of a pulse to its
  period
• Changing of the duty cycle is defined as PWM
• CCP pin is set as an output
• Count for period and duty cycle loaded into CCP
  registers
• Varying the duty cycle generates PWM
• PWM for DC Motor Control
• Varies average DC voltage
• Controls DC motor speed

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PWM Mode

• CCP module with Timer2
• Output a pulse wave form for a given
  frequency/duty cycle
• Duty cycle
• CCPR1L register
• Period
• PR2 register
• When TMR2 is equal to PR2
• TMR2 is cleared
• Pin RC2/CCP1 of PORTC is set high
• PWM duty-cycle byte loaded into CCPR1

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MPLAB X IDE

• Compile/Assemble Source Files
• Linker Script for specific Microcontroller
• Test Programs
• Simulator
• In Circuit Debugger
• PICKit 3
• Program Microcontroller
• PICKit 3

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PICKit 3
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PIC18 Explorer Demo Board
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PIC18F8722
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2WD Robot Chassis
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Dual H-Bridge Motor Driver
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Microcontroller Applications

• Analog to Digital Conversion
• Interface Analog Sensors (Transducers)
• Pulse Width Modulation
• DC Motor Control
• MPLAB X IDE
• Programming and Debugging
• PIC18 Explorer Demo Board
• PIC18F8722 with lots of I/O
• Robot Chassis
• H-Bridge Motor Driver