[AVR] UART 실험

제목 : 

날짜 : 21.04.07

주제 : UART 연습

목표 : UART를 활용하여 LED 제어

<활동>

- main.c -

 #define F_CPU 16000000UL
 #include <avr/io.h>
 #include <util/delay.h>
 #include <avr/interrupt.h>
 #include <stdio.h>
 #include <string.h>
#include "uart0.h"

FILE OUTPUT = FDEV_SETUP_STREAM(UART0_Transmit, NULL, _FDEV_SETUP_WRITE);

char rxBuff[100] = {0,};
uint8_t rxFlag = 0;

ISR(USART0_RX_vect)
{
	static uint8_t tail = 0;
	uint8_t rxData = UDR0;
	
	if(rxData == ';')
	{
		rxBuff[tail] = '\0';
		tail = 0;
		rxFlag = 1;
	}
	else
	{
		rxBuff[tail] = rxData;
		tail++;
	}
}

 int main(void)
 {
	 DDRF |= (1<<PF6) | (1<<PF7);
	 UART0_Init();
	 stdout =&OUTPUT;
	 
	 sei();
	 
	 while (1)
	 {
		 if(rxFlag == 1)
		 {
			 rxFlag = 0;
			 if(strncmp(&rxBuff[0],"LED0",4) == 0)
			 {
				 if(strncmp(&rxBuff[4],"ON",2) == 0)
				 {
					 PORTF |= (1<<PF6);
					  printf("LED0 ON\n");
				 }
				 else if(strncmp(&rxBuff[4],"OFF",3) == 0)
				 {
					 PORTF &= ~(1<<PF6);
					 printf("LED0 OFF\n");
				 }
			 }
			 else if(strncmp(&rxBuff[0],"LED1",4) == 0)
			 {
				 if(strncmp(&rxBuff[4],"ON",2) == 0)
				 {
					 PORTF |= (1<<PF7);
					  printf("LED1 ON\n");
				 }
				 else if(strncmp(&rxBuff[4],"OFF",3) == 0)
				 {
					 PORTF &= ~(1<<PF7);
					  printf("LED1 OFF\n");
				 }
			 }
		 }
	 }
 }

- uart0.c

#include "uart0.h"

void UART0_Init(void)
{
	UBRR0H=0x00;   //대부분 0
	UBRR0L=16;      //데이터 통신 속도를 의미한다. 115200 baudrate
	UCSR0A|=(1<<U2X0);
	
	UCSR0B|=(1<<RXEN0)|(1<<TXEN0);//Rx enable/ Tx enable
	
	UCSR0B|=(1<<RXCIE0);// 수신 Rx UART0 인터럽트 Enabale
}

void UART0_Transmit(unsigned int data)
{
	/* Wait for empty transmit buffer */
	while ( !( UCSR0A & (1<<UDRE0)) )
	;
	/* Put data into buffer, sends the data */
	UDR0 = data;
}

unsigned char UART0_Receive(void)
{
	/* Wait for data to be received */
	while ( !(UCSR0A & (1<<RXC0)) )
	;
	/* Get and return received data from buffer */
	return UDR0;
}

void UART0_print_string(char *str)
{
	for(int i=0;str[i];i++)
	{
		UART0_Transmit(str[i]);
	}
}

- uart0.h -

#ifndef UART0_H_
#define UART0_H_

 #include <avr/io.h>
 
void UART0_Init(void);
void UART0_Transmit(unsigned int data);
unsigned char UART0_Receive(void);
void UART0_print_string(char *str);

#endif /* UART0_H_ */

 

<파일>

uart0.zip

0.03MB