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Lab 1: Introduction

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Lab1: Introduction

• Configure ATMEL AVR Starter Kit 500 (STK500), a prototyping/development board for Lab1. ATmega16 (4.5 -5.5 V) is the chip used on your board. Some may have ATmega16L (low voltage 2.7 – 5.5 V) .– Lab1 requires

• One UART port for programming, COM1• One UART port for communication, COM2• Connect a 6-wire cable between Target ISP Header and 6-

pin ISP Header.• Connect a 10-wire cable between Port and LEDs

• Become familiar with the C-compiler from CodeVision.– Lab1 requires writing 3 simple C programs to activate LEDs in

different patterns.– Lab1 requires writing 1 simple C program to talk to a terminal.

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AVR STK 500 Components

Atmeg16

Atmeg8515

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COM1

To PC COM2 portor other available COM port

COM port connections:COM1 for programming your code onto AVRCOM2 for communication to display your program output

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Programming

Connecting LEDs and PORTB

Connecting Switches to PORTD

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RS232 connecting to PORTDRXD PD0TXD PD1

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Lab1: Introduction

• Pre-lab Assignments– Read Chapter 1 of the textbook: Embedded C

Programming and the Atmel AVR by Barnett, Cox, & O’Cull (BCO).

– Read STK500 user guide– Complete the Pre-lab Questions on page 1-4.

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Pre-Lab Questions for Lab 1

• When setting up a timer to generate an interrupt every half second, what value must the timer be initialized to (if counting down)?

• What is the clock frequency of the AVR mcu on the STK500 when shipped?

• On the average, how many clock cycles are required per instruction?

• Using your answers from questions 2) and 3) above, how long does a typical instruction take to run on the AVR mcu?

• Write pseudo c-code to toggle every other light to blink every ¼ of a second. Example: 01010101 -> 10101010 -> 01010101 ->…

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In-Lab Tasks

• Program 1 called led.c; almost a duplication of a program in the tutorial “Getting Started with the CodeVision AVR C Compiler.”

• Program 2 called led2.c; different patterns of LEDs

• Program 3 called led3.c; different patterns of LEDs and different delay

• Program 4 called HelloWorld.c; program COM2 to display program output on a terminal

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CodeVision Wizard

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CodeVision Wizard

Select the chip on your board

Select the right frequency

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CodeVision Wizard

Set Port A as Output Port

Need to set Ports as input orOutput depending on your programs

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CodeVision Wizard

Set USART parametersBaud rate, Data, Stop bitParity.

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Set the timer parameters

CodeVision Wizard

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CodeVision Wizard

CodeVision Wizardgenerates C code according tospecifications you selected, i.e.,I/O Ports, Timer, UART parametersetc.

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CodeVision Wizard#include <mega16.h>

// LED's are on PORTBunsigned char ledStatus = 0xFE;

// Timer 1 overflow interrupt service routineinterrupt [TIM1_OVF] void timer1_ovf_isr(void){// Reinitialize Timer 1 valueTCNT1H=0xF8;TCNT1L=0xFB;// Place your code here. . . . . .. . . . . .

}

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CodeVision Wizard// Declare your global variables here

void main(void){// Declare your local variables here

// Input/Output Ports initialization// Port A initialization// Func0=In Func1=In Func2=In Func3=In Func4=In Func5=In Func6=In Func7=In // State0=T State1=T State2=T State3=T State4=T State5=T State6=T State7=T PORTA=0x00;DDRA=0x00;

// Port B initialization// Func0=Out Func1=Out Func2=Out Func3=Out Func4=Out Func5=Out Func6=Out

Func7=Out // State0=1 State1=1 State2=1 State3=1 State4=1 State5=1 State6=1 State7=1 PORTB=0xFF;DDRB=0xFF;

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CodeVision Wizard// Port C initialization// Func0=In Func1=In Func2=In Func3=In Func4=In Func5=In Func6=In Func7=In // State0=T State1=T State2=T State3=T State4=T State5=T State6=T State7=T PORTC=0x00;DDRC=0x00;

// Port D initialization// Func0=In Func1=In Func2=In Func3=In Func4=In Func5=In Func6=In Func7=In // State0=T State1=T State2=T State3=T State4=T State5=T State6=T State7=T PORTD=0x00;DDRD=0x00;

// Timer/Counter 0 initialization// Clock source: System Clock// Clock value: Timer 0 StoppedTCCR0=0x00;TCNT0=0x00;

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CodeVision Wizard// Timer/Counter 1 initialization// Clock source: System Clock// Clock value: 3.594 kHz// Mode: Normal top=FFFFh// OC1A output: Discon.// OC1B output: Discon.// Noise Canceler: Off// Input Capture on Falling EdgeTCCR1A=0x00;TCCR1B=0x05;TCNT1H=0xF8;TCNT1L=0xFB;OCR1AH=0x00;OCR1AL=0x00;OCR1BH=0x00;OCR1BL=0x00;

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CodeVision Wizard// Timer/Counter 2 initialization// Clock source: System Clock// Clock value: Timer 2 Stopped// Mode: Normal top=FFh// OC2 output: DisconnectedTCCR2=0x00;ASSR=0x00;TCNT2=0x00;OCR2=0x00;

// External Interrupt(s) initialization// INT0: Off// INT1: OffGIMSK=0x00;MCUCR=0x00;

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CodeVision Wizard// Timer(s)/Counter(s) Interrupt(s) initializationTIMSK=0x04;

// Analog Comparator initialization// Analog Comparator: Off// Analog Comparator Input Capture by Timer/Counter 1: Off// Analog Comparator Output: OffACSR=0x80;

// Global enable interrupts#asm("sei")

while (1) { // Place your code here

};}

CodeVision Wizard

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from a student’s Lab1 Report

Results and Discussion:1.Following the “Getting Started” instructions as closely as possible actually worked as advertised and resulted in the AVR flashing the LEDs in order. I was pleased with how straight forward the process was and experimented some with changing the interrupt time and the order of the flashing lights.2.…

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Lab 1: Introduction• led.c; led2.c; led3.c;

– Different delays can be implemented by including delay.h; or you can write your own subroutine.

#include <delay.h> // delay_ms(125)• HelloWorld.c

– Needs I/O functions, the Wizard will add

#include <stdio.h> into the generated C program after specifying UART parameters.

#include <mega16.h>

// Standard Input/Output functions#include <stdio.h>

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#include <mega16.h>#include <delay.h>// Standard Input/Output functions#include <stdio.h>void main(void){ …………………………….// UART initialization// Communication Parameters: 8 Data, 1 Stop, No Parity// UART Receiver: On// UART Transmitter: On// UART Baud rate: 9600UCR=0x18;UBRR=0x17;while (1){// Place your code heredelay_ms(500); //Use delay function to generate ½ second interval.printf(“Hello World “); //Output “Hello World”.};}

Part of HelloWorld.c

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Lab Report Format

1. Cover page (include date due, date turned in)

2. Prelab questions and answers (typed)

3. Summary of the lab tasks

4. In-lab tasks, questions and solutions including software and hardware

5. Results and Discussion

6. Code listing for each task

All lab report should be typed and turned in a hard copy on time

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Check Out Sheet Box Number: Name:Date:

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In-lab demo (EN 229) Create project Configure peripherals Add C-code Hook up STK500 Compile and build Download and run