Programming and Interfacing

Transcription

1 AtmelAVR Microcontroller Primer: Programming and Interfacing Second Edition

2 f^r**t>*-**n*c contents Preface xv AtmelAVRArchitecture Overview ATmegal64 Architecture Overview Reduced Instruction Set Computer Assembly Language Instruction Set ATmegal 64 Architecture Overview Nonvolatile and Data Memories In-System Programmable Flash EEPROM Byte-Addressable EEPROM Static Random Access Memory Programmable Lock Bits Port System 1.4 Peripheral Features Internal Subsystems Time Base Timing Subsystem Pulse Width Modulation Channels Serial Communications Analog-to-Digital Converter Interrupts 1.5 Physical and Operating Parameters Packaging Power Consumption Speed Grades Application: ATmegal64Testbench Hardware Configuration Software Configuration Programming the ATmegal Programming Procedure Software 18 Portability 1.9 Summary

3 1.10 References and Further Reading Chapter Problems 18 2 Serial Communication Subsystem Serial Communications Serial Communication Terminology Asynchronous versus Synchronous Serial Transmission Baud Rate Full Duplex Nonreturn to Zero Coding Format The RS-232 Communication Protocol Parity American Standard Code for Information Interchange Serial USART System Overview System Operation and Programming Example: Global Positioning System Serial Peripheral Interface Two-Wire Serial Interface Summary References and Further Reading Chapter Problems 36 3 Analog-to-Digital Conversion Background Theory Analog versus Digital Signals Sampling, Quantization, and Encoding Resolution and Data Rate Analog-To-Digital Conversion Process Operational Amplifiers ADC Conversion Technologies Successive Approximation Integration Counter-Based Conversion Parallel Conversion The AtmelATmegal64 ADC System Block Diagram 58

4 xi Registers Programming the ADC Digital-to-Analog Conversion Summary References and Further Reading Chapter Problems 64 4 Interrupt Subsystem Interrupt Theory ATmegal64 Interrupt System Programming An Interrupt Application External Interrupts Internal Interrupt Summary References and Further Reading Chapter Problems 75 5 Timing Subsystem Overview Timing related terminology Frequency Period Duty Cycle Timing System Overview Applications Input Capture Measuring External Timing Event Counting Events Output Compare Generating Timing Signals to Interface External Devices Industrial Implementation Case Study (PWM) Overview of the Atmel Timers Timer 0 System Modes of Operation Timer 0 Registers Timer 1 91

5 5.7.1 Timer 1 Registers Timer Programming the Timer System Precision Delay Pulse Width Modulation Input Capture Mode Servo Motor Control with the PWM system Summary References Chapter Problems Ill 6 AtmelAVR Operating Parameters and Interfacing Operating Parameters Input Devices Switches Switch Debouncing Keypads Sensors Output Devices Light-Emitting Diodes Seven-Segment LED Displays Tristate LED Indicator Dot Matrix Display Liquid Crystal Display High-Power DC Devices DC Motor Speed and Direction Control H-bridge direction control Servo motor interface Stepper motor control AC Devices Summary References and Further Reading Chapter Problems Embedded Systems Design What is an embedded system? 147

6 xiii 7.2 Embedded system design process Project Description Background Research Pre-Design Design Implement Prototype Preliminary Testing Complete and Accurate Documentation Application: Flight Simulator Panel Autonomous Maze Navigating Robots Blinky602Arobot Requirements Circuit diagram Structure chart UML activity diagrams Microcontroller code Mountain. Maze Navigating Robot Description Requirements Circuit diagram Structure chart UTvtL activity diagrams Microcontroller code Mountain Maze Project extensions Summary References and Further Reading Chapter Problems 205 A ATmegal64 Register Set 207 B ATmegal64 Header File 211 Authors'Biographies 223 Index 225