Embedded system design using arduino

EMBEDDED SYSTEM DESIGN USING ARDUINO

Santosh Kumar Verma

Department of Computer Science and Information TechnologyJaypee Institute of Information Technology, Noida

Content

1. Introduction of µp and µc2. Introduction of 8051 µc3. Introduction of Arduino4. Atmega328 : Basics and internal Architecture5. Atmega328 : Instruction Set6. Arduino programming interface7. Analog/Digital components and its application

with arduino8. References

Do you know computer organization?Arithmetic Logic Unit

Memory

OutputInput Control Unit

- How does it work?- Map it’s units in personal computer –

InputOutputMemoryALU

Software – System software & Application software

Introduction to Microprocessor

ARITHMATIC LOGIC UNIT

CONTROL UNIT

MEMORY

INPUT OUTPUT

MICROCOMPUTER

MICROPROCESSOR

Microprocessor Based System

INPUT µP OUTPUT

MEMORY

INPUT µC OUTPUT

MEMORYExternal memory in addition to internal memory may be desired

MEMORY

Address, Data and Control Bus• Bus - defined pathway for transfer of digital information between

different units.• To write data to memory or output device.

- µp needs to send . Address of memory location or port address of device.. Data . Write control signal

• To read data from memory or Input device - µp needs to send . Address and . Read Control Signal- Memory/device sends – data.

Thus three pathways (buses) for 3 types of digital information.Address Bus - From µp to devices - Unidirectional.Data Bus - From µp to devices & devices to µp - BidirectionalControl - From µp to devices & from devices to µp [Interrupt, DMA] - Bidirectional

Now let us redraw the computer organization diagram

Address Bus

I/ODevice

I/ODevice

I/ODevice Memory

µp Control Bus

Data Bus

Microcontroller

A microcontroller is a complete computer system, including a CPU, memory, a clock oscillator, and I/O on a single integrated circuit chip. [1]

ANALOGINPUTS

http://www.freescale.com/files/microcontrollers/doc/ref_manual/M68HC05TB.pdf, p. 25

http://www.freescale.com/files/microcontrollers/doc/ref_manual/M68HC05TB.pdf

General Facilities 8 bit CPU On chip clock oscillator 4 KB of ROM (Program memory) 128 bytes RAM (Data Memory) 21 Special Function Registers(SFR) 32 I/O lines (Ports P0 to P3) 64 KB address space for external data memory 64 KB address space for program memory

8051 MICROCONTROLLER

2- 16 bit timer/counter

5 source interrupt structure

Full duplex serial port

Bit addressability

Bit processing capability

MCS-51 compatible chips

8031 – Romless version – 4KB ROM not available

8751 – EPROM version – 4KB EPROM

8052- (8 KB ROM + 256 byte Data memory)



• The 8051 was one of the very early microcontrollers (~1980).

• One of the early Arduino-like project was based on

the 8051, in the form of "8052 Basic" board.

• Atmel, Mentor Graphics, Intel, Honeywell, and Maxim (Dallas Semiconductor), and may more have a variety of 8051 chips.


WHAT IS ARDUINO?• Introduced in 2005 as a project for students at the Interaction Design Institute

Ivrea in Ivrea, Italy, Arduino is a single board microcontroller.

• An Arduino board consists of an Atmel 8-bit AVR microcontroller with complementary components to facilitate programming and incorporation into other circuits [2].

• Arduino can sense the environment by receiving input from a variety of sensors and can affect its surroundings by controlling lights, motors, and other actuators.

• The boards can be assembled or purchased preassembled; the open-source IDE can be downloaded for free.

• The Arduino programming language is very simple and follows C like syntax.

• Arduino projects can be stand-alone or they can communicate with software running on a computer (e.g. Processing).

WHY ARDUINO?• Other similar microcontrollers platforms are:

Parallax Basic Stamp, Netmedia's BX-24, Phidgets, MIT's Handyboard, and many more.

• All these platforms have an easy-to-use package.

Why Arduino?

Arduino also simplifies the process of working withmicrocontrollers, but it offers some advantage:

1. Inexpensive - Arduino boards are relatively inexpensive compared to other microcontroller platforms.

2. Cross-platform - The Arduino software runs on Windows, Macintosh OSX, and Linux operating systems. Most microcontroller systems are limited to Windows.

3. Simple, clear programming environment - The Arduino programming environment is easy-to-use.

4. Open source and extensible software- The Arduino software is published as open source tools. The language can be expanded through C++ libraries.

5. Open source and extensible hardware -The Arduino is based on Atmel's ATMEGA8 and ATMEGA168 microcontrollers.

ADVANTAGES OF ARDUINO

Features 8051 Modern Microcontrollers

Execution Time 12 clock cycles/Instr. 1 clock cycle/Instr.

Architecture Harvard Harvard

Memory Internal + External (may compromise with security)

Program memory- Internal Data memory ( Int+Ext)

Instruction Set Architecture (ISA)

CISC RISC

Port With limited functionality Fully Functional

Timer Simple PWM, Complex features

Intra Communication Busses

Few Master/Slave SPI Serial InterfaceByte-oriented 2-wire Serial Interface (I2C)

Operating Mode Sleep Sleep, Power Down, Active

ADC NIL At least 6-channel 10-bit ADC

WDT (Watchdog Timer) NIL Present

BOR (Brownout Reset) NIL Present

THE GOOGLE TRENDS FOR ARDUINO RELATIVE TO OTHER EMBEDDED TERMS

ATmega328 data sheet pp. 2, 5 http://www.adafruit.com/index.php?main_page=popup_image&pID=50

ATMEGA328 INTERNAL ARCHITECTURE

ATMEGA328 MICROCONTROLLER

Pin numberPin name

Special function

Source:http://www.atmel.com/dyn/products/product_card.asp?PN=ATmega328P

Note the limitations!

p. 316

ATMEGA328 FEATURES 1

http://www.atmel.com/Images/Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet.pdf

High Performance, Low Power AVR® 8-Bit Microcontroller– Advanced RISC Architecture– 131 Powerful Instructions – Most Single Clock Cycle Execution– 32 x 8 General Purpose Working Registers– Up to 20 MIPS Throughput at 20 MHz

High Endurance Non-volatile Memory Segments– 4/8/16/32K Bytes of In-System Programmable Flash program memory (ATmega48PA/88PA/168PA/328P)– 256/512/512/1K Bytes EEPROM– 512/1K/1K/2K Bytes Internal SRAM– Data retention: 20 years at 85°C/100 years at 25°C(1)

http://www.atmel.com/Images/Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet.pdf

ATMEGA328 FEATURES 2 Peripheral Features

– Two 8-bit Timer/Counters– One 16-bit Timer/Counter– Real Time Counter with Separate Oscillator– Six PWM Channels– 6-channel 10-bit ADC – Programmable Serial USART– Master/Slave SPI Serial Interface

Special Microcontroller Features– Internal Calibrated Oscillator– External and Internal Interrupt Sources– Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby, and Extended Standby

ATMEGA328 FEATURES 3 I/O and Packages

– 23 Programmable I/O Lines

Operating Voltage:– 1.8 - 5.5V for ATmega48PA/88PA/168PA/328P

Temperature Range:– -40°C to 85°C

Speed Grade:– 0 - 20 MHz @ 1.8 - 5.5V

Low Power Consumption at 1 MHz, 1.8V, 25°C for ATmega48PA/88PA/168PA/328P:

– Active Mode: 0.2 mA– Power-down Mode: 0.1 μA– Power-save Mode: 0.75 μA

Instruction Set Summary




Absolute Maximums

ATmega328 data sheet p. 316

Microcontroller Ports and Pins

The communication channels through which information flows into or out of the microcontroller Ex. PORTB

Pins PB0 – PB7 May not be contiguous Often bi-directional

C

See next slides!

Port Pin Data Directionality

• Input– When you want to take information from the external

world (sensors) into the MCU• Output

– When you want to change the state of something outside the MCU (turn a motor on or off, etc.)

• Pins default to input direction on power-up or reset.• Your program can set or change the directionality of

a pin at any time

ATmega328Block Diagram

Input

Output

Setting the Pin Data Direction

• Arduino– pinMode(pin_no., dir)

• Ex. Make Arduino pin 3 (PD3) an output– pinMode(3, OUTPUT);– pinMode(PIN_D3, OUTPUT); // with me106.h

– Note: one pin at a time• Suppose you wanted Arduino pins 3, 5, and 7 (PD3,

PD5, and PD7) to be outputs?• Is there a way to make them all outputs at the same

time?

Pin Used as an Output

• Turn on an LED, which is connected to pin Arduino pin 0 (PD0)– What should the data direction

be for pin 0 (PD0)?• pinMode(____, ____);

– Turn on the LED• digitalWrite(0,HIGH);

– Turn off the LED• digitalWrite(0,LOW);

ATmega328

Arduinopin 0(PD0)

• Recall the question:– Is there a way change the data direction for a set of pins all

at the same time?• All the work of MCU happens through registers

(special memory locations)– Registers on the Atmega328 are 8-bits wide

• The data direction register (DDRx) handles the data directions for pins in PORTx

Source:http://www.atmel.com/dyn/products/product_card.asp?PN=ATmega328P p. 93

Pin Used as an Output

Data Direction Register• If the bit is zero -> pin will be an input

– Making a bit to be zero == ‘clearing the bit’• If the bit is one -> pin will be an output

– Making a bit to be one == ‘setting the bit’• To change the data direction for a set of pins

belonging to PORTx at the same time:1. Determine which bits need to be set and cleared in DDRx2. Store the binary number or its equivalent (in an alternate

base, such as hex) into DDRx

Example 1

• Arduino approach • Alternate approach

Make Arduino pins 3, 5, and 7 (PD3, PD5, and PD7) to be outputs

pinMode(3, OUTPUT);pinMode(5, OUTPUT); pinMode(7, OUTPUT);

DDRD = 0b10101000;

or

DDRD = 0xA8;

Or if me106.h is used:

pinMode(PIN_D3, OUTPUT);pinMode(PIN_D5, OUTPUT); pinMode(PIN_D7, OUTPUT);

Example 2

• Arduino approach • Alternate approach

Make pins Arduino pins 0 and 1 (PD0 and PD1) inputs, and turn on the LEDs connected to it.

pinMode(0, INPUT);pinMode(1, INPUT); digitalWrite(0, HIGH);digitalWrite(1, HIGH);

DDRD = 0; // all PORTD pins inputsPORTD = 0b00000011;orPORTD = 0x03;

Or if me106.h is used:

pinMode(PIN_D0, INPUT);pinMode(PIN_D1, INPUT); digitalWrite(PIN_D0, HIGH);digitalWrite(PIN_D1, HIGH);

OFFICIAL BOARDS

Arduino Duemilanove http://www.arduino.cc/en/Main/ArduinoBoardDuemilanove

http://arduino.cc/en/uploads/Main/ArduinoDuemilanove.jpg

Pin 13 LED

USBconnector

Barrel jack

Digital pins header

Reset button

ATmega328 MCU

Analog pins header

Power-ground header

See the handout: Arduino_ATmega328_pin_mapping_and_schematic

Arduino Uno R3

http://www.adafruit.com/index.php?main_page=popup_image&pID=50

ATmega16u2 replaces FT232RL for USB-serial comms

See: http://learn.adafruit.com/arduino-tips-tricks-and-techniques/arduino-uno-faq

Arduino DueAtmel SAM3X8E processor (32 bit ARM Cortex M3 architecture, 84MHz)

http://www.adafruit.com/index.php?main_page=popup_image&pID=1076

See: http://arduino.cc/en/Main/ArduinoBoardDue

Note: 3.3 V !!

Arduino Duemilanove/Uno Features

Microcontroller ATmega168/328

Operating Voltage 5V

Input Voltage (recommended) 7-12V

Input Voltage (limits) 6-20V

Digital I/O Pins 14 (of which 6 provide PWM output)

Analog Input Pins 6

DC Current per I/O Pin 40 mA

DC Current for 3.3V Pin 50 mA

Flash Memory 16 KB (ATmega168) or 32 KB (ATmega328) of which 2 KB used by bootloader

SRAM 1 KB (ATmega168) or 2 KB (ATmega328)

EEPROM 512 bytes (ATmega168) or 1 KB (ATmega328)

Clock Speed 16 MHz

http://www.arduino.cc/en/Main/ArduinoBoardDuemilanove

• The Arduino Duemilanove can be programmed with the Arduino software.

• The Arduino integrated development environment (IDE) is written in Java, and is derived from the IDE for the Processing programming language.

• It includes a code editor with features such as syntax highlighting, brace matching, and automatic indentation, and is also capable of compiling and uploading programs to the board with a single click. A program or code written for Arduino is called a "sketch".[3]

• Arduino programs are written in C or C++.

About Arduino Programming

Getting Started w/ Arduino on Windows1. Get an Arduino board and USB cable2. Download the Arduino environment3. Connect the board with PC4. Install the drivers5. Launch the Arduino application6. Open the blink example7. Select your board like UNO etc.8. Select your serial port9. Upload the program

Arduino Programming Interface

Sample Program of LED BLINK

• An arduino program == ‘sketch’– Must have:

• setup()• loop()

– setup()• configures pin modes and

registers– loop()

• runs the main body of the program forever

– like while(1) {…}

– Where is main() ?• Arduino simplifies things• Does things for you

/* Blink - turns on an LED for DELAY_ON msec, then off for DELAY_OFF msec, and repeatsBJ Furman rev. 1.1 Last rev: 22JAN2011*/#define LED_PIN 13 // LED on digital pin 13#define DELAY_ON 1000#define DELAY_OFF 1000

void setup(){ // initialize the digital pin as an output: pinMode(LED_PIN, OUTPUT); }

// loop() method runs forever,// as long as the Arduino has power

void loop() { digitalWrite(LED_PIN, HIGH); // set the LED on delay(DELAY_ON); // wait for DELAY_ON msec digitalWrite(LED_PIN, LOW); // set the LED off delay(DELAY_OFF); // wait for DELAY_OFF msec}

main(){ init(); setup(); while (1) loop();}

Structure of an Arduino Programin C language

/* Blink - turns on an LED for DELAY_ON msec, then off for DELAY_OFF msec, and repeatsBJ Furman rev. 1.1 Last rev: 22JAN2011*/#define LED_PIN 13 // LED on digital pin 13#define DELAY_ON 1000#define DELAY_OFF 1000

void setup(){ // initialize the digital pin as an output: pinMode(LED_PIN, OUTPUT); }

// loop() method runs forever,// as long as the Arduino has power

void loop() { digitalWrite(LED_PIN, HIGH); // set the LED on delay(DELAY_ON); // wait for DELAY_ON msec digitalWrite(LED_PIN, LOW); // set the LED off delay(DELAY_OFF); // wait for DELAY_OFF msec}

Various Components

Projects Using Arduino1. Line follower/Path follower2. Obstacles Avoider3. Automatic car parking 4. Driverless car5. Quad copter6. Water-level detection in soil7. Surveillance System8. Dancing/ Funny Robot9. Smart phone Garage Door Opener10. Intrusion alarm11. Thermostat12. Balance multirotor motor using arduino & acceleromter13. Email notifier14. LED Matrix Control15. Maze Solver Robot

REFERENCES1. http://www.freescale.com/files/microcontrollers/doc/ref_manual/M68HC05T

B.pdf, p. 25

2. Arduino, “Avalable at http://www.arduino.cc,” 2010.

3. "Programming Arduino Getting Started with Sketches“ : http://www.amazon.com/Programming-Arduino-Getting-Started-Sketches/dp/0071784225/ref=sr_1_1?s=books&ie=UTF8&qid=1364494138&sr=1-1&keywords=arduino+sketches). McGraw-Hill. Nov 8, 2011. Retrieved 2013-03-28.

4. C. L. Dym, A. M. Agogino, D. D. Frey, and L. J. Leifer, “Engineering design thinking, teaching, and learning,” Journal of Engineering Education, vol. 94, pp. 103–120, 2005. [Online]. Available: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.72.1593

5. http://www.atmel.com/dyn/products/product_card.asp?PN=ATmega328

6. J. Provost, “Why the arduino won and why it’s here to stay,” Tech.Rep.

7. http://learn.adafruit.com/arduino-tips-tricks-and-techniques/arduino-uno-faq



http://www.atmel.com/dyn/products/product_card.asp?PN=ATmega328

Thank You.