Objectives
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Introduce the ATmega328P microcontroller.
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Describe the status register of the ATmega328P.
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Describe the pinout diagrams for each ATmega328P package.
Chapter 4 The ATmega328P Microcontroller
The microcontroller that will be featured in this textbook is the AVR ATmega328P. This 8-bit microcontroller is used in the popular Arduino Uno R3 system, which contains additional features including (but not limited to): power regulator, bootloader, USB connection, pin headers for each I/O pin, and the availability of the Arduino IDE for writing C code. The Arduino is a relatively inexpensive microcontroller package. By the conclusion of this textbook, you will have all of the information you need to develop your own embedded systems and "smart projects" at home using this platform.
The ATmega328P datasheet[16.14] is the single most useful and important document to understanding everything that needs to be known about the microcontroller. It is available for download on the Microchip website. The first time you look at it, it may seem overwhelming. Perhaps you only understand a few words here and there. Do not be intimidated. Every time you refer to the datasheet, you will find that you understand a little more. Eventually, your knowledge will expand, and more and more of the datasheet will be part of your understanding. At the very least, become comfortable with the features of the ATmega328P, which are detailed on the front page of the datasheet. Some of this front page has been paraphrased below.
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High performance, low power
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AVR 8-bit microcontroller family
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Advanced RISC architecture (Section 2.1)
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131 powerful instructions
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32 x 8 general purpose working registers (Subsection 13.2.1)
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Up to 16 MIPS throughput at 16 MHz
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High endurance non-volatile memory segments
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32K bytes flash program memory (Section 13.1)
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1K bytes EEPROM (Section 13.3)
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2K bytes internal SRAM (Section 13.2)
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Write/erase cycles: 10,000 flash/100,000 EEPROM
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Peripheral features
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Two 8-bit timer/counters (Section 9.2)
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One 16-bit timer/counter (Section 9.2)
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Six PWM channels (Section 9.6)
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10-bit ADC (Section 6.4)
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Programmable serial USART (Section 10.3)
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Primary/secondary SPI serial interface (Section 10.2)
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Byte-oriented 2-wire serial interface (Section 10.4)
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Programmable watchdog timer with separate on-chip oscillator (Section 9.8)
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On-chip analog comparator (Section 6.5)
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Interrupt and wake-up on pin change (Section 8.1)
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Special microcontroller features
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Power-on reset and programmable brown-out detection
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Internal calibrated oscillator (Section 9.1)
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Six sleep modes (Section 11.1)
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Operating voltage
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2.7 V to 5.5 V for ATmega328P
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