1 Lab 1: Introduction

2 Configure ATMEL AVR Starter Kit 500 (STK500), a prototyping/development board for Lab1. ATmega16 ( 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.

3 AVR STK 500 Components Atmeg16 Atmeg8515

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5 COM1 To PC COM2 port or other available COM port COM port connections: COM1 for programming your code onto AVR COM2 for communication to display your program output

6 Programming Connecting LEDs and PORTB Connecting Switches to PORTD

7 RS232 connecting to PORTD RXD  PD0 TXD  PD1

8 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.

9 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: > > >…

10 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

11 CodeVision Wizard

12 CodeVision Wizard Select the chip on your board Select the right frequency

13 CodeVision Wizard Set Port A as Output Port Need to set Ports as input or Output depending on your programs

14 CodeVision Wizard Set USART parameters Baud rate, Data, Stop bit Parity.

15 Set the timer parameters CodeVision Wizard

16 CodeVision Wizard generates C code according to specifications you selected, i.e., I/O Ports, Timer, UART parameters etc.

17 CodeVision Wizard #include // LED's are on PORTB unsigned char ledStatus = 0xFE; // Timer 1 overflow interrupt service routine interrupt [TIM1_OVF] void timer1_ovf_isr(void) { // Reinitialize Timer 1 value TCNT1H=0xF8; TCNT1L=0xFB; // Place your code here... }

18 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;

19 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 Stopped TCCR0=0x00; TCNT0=0x00;

20 CodeVision Wizard // Timer/Counter 1 initialization // Clock source: System Clock // Clock value: kHz // Mode: Normal top=FFFFh // OC1A output: Discon. // OC1B output: Discon. // Noise Canceler: Off // Input Capture on Falling Edge TCCR1A=0x00; TCCR1B=0x05; TCNT1H=0xF8; TCNT1L=0xFB; OCR1AH=0x00; OCR1AL=0x00; OCR1BH=0x00; OCR1BL=0x00;

21 CodeVision Wizard // Timer/Counter 2 initialization // Clock source: System Clock // Clock value: Timer 2 Stopped // Mode: Normal top=FFh // OC2 output: Disconnected TCCR2=0x00; ASSR=0x00; TCNT2=0x00; OCR2=0x00; // External Interrupt(s) initialization // INT0: Off // INT1: Off GIMSK=0x00; MCUCR=0x00;

22 CodeVision Wizard // Timer(s)/Counter(s) Interrupt(s) initialization TIMSK=0x04; // Analog Comparator initialization // Analog Comparator: Off // Analog Comparator Input Capture by Timer/Counter 1: Off // Analog Comparator Output: Off ACSR=0x80; // Global enable interrupts #asm("sei") while (1) { // Place your code here }; }

CodeVision Wizard 23 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.…

24 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_ms(125) HelloWorld.c –Needs I/O functions, the Wizard will add #include into the generated C program after specifying UART parameters. #include // Standard Input/Output functions #include

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

26 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

27 Check Out Sheet Box Number: Name: Date:

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