ARDUINO

megaAVR 0-series (ATMEGA4809)

CODE

#include <avr/io.h>
#include <stdio.h>
#include <avr/delay.h>

#define F_CPU 3333333
#define BAUD_RATE 9600

#define _ADC0_CTRLA				(unsigned char *)(0x0600)
#define _ADC0_CTRLA				(unsigned char *)(0x0600)
#define _ADC0_MUXPOS			(unsigned char *)(0x0606)
#define _ADC0_COMMAND			(unsigned char *)(0x0608)
#define _ADC0_RES				  (unsigned char *)(0x0610)
#define _ADC_RESSEL_10BIT_gc	(0x01<<0)
#define _ADC_ENABLE_bm			(0x01)
#define _ADC_STCONV_bm			(0x01)

#define USART0_BAUD_RATE(BAUD_RATE) ((float)(F_CPU * 64 / (16 * (float)BAUD_RATE)) + 0.5)
#define PIN(N)	(1<<N)

void ADC_init(void);
uint16_t ADC_read(int ch);

void USART3_init(void);
void USART3_Transmit(unsigned char);
int USART3_printChar(char, FILE *stream);

FILE USART_stream = FDEV_SETUP_STREAM(USART3_printChar, NULL, _FDEV_SETUP_WRITE);

void USART3_init(void){
	PORTB_DIR |= PIN(0);
	PORTB_DIR &= ~PIN(1);
	
	USART3_BAUD = (uint16_t)USART0_BAUD_RATE(BAUD_RATE);
	USART3_CTRLB |= USART_TXEN_bm | USART_RXEN_bm;
}

int USART3_printChar(char c, FILE *stream){
	USART3_Transmit(c);
	
	return 0;
}

void USART3_Transmit(unsigned char data){
	while(!((USART3_STATUS)&USART_DREIF_bm));
	USART3_TXDATAL = data;
}	

void ADC_init(void){
	PORTD_PIN0CTRL = PORT_ISC_INPUT_DISABLE_gc;

	ADC0_CTRLA = ADC_RESSEL_10BIT_gc;
	ADC0_CTRLC |= ADC_REFSEL_VDDREF_gc;
	ADC0_CTRLA |= ADC_ENABLE_bm | ADC_FREERUN_bm;
}

uint16_t ADC_read(int ch){
	ADC0_MUXPOS = ch;
	ADC0_COMMAND |= ADC_STCONV_bm;
	
	while(!(ADC0_COMMAND) & ADC_STCONV_bm);
	
	return (uint16_t)ADC0_RES;
}

int main(void)
{
	USART3_init();
	ADC_init();
	stdout = &USART_stream;

    while (1) 
    {
		int X_value = ADC_read(0);
		_delay_ms(10);
		int Y_value = ADC_read(1);
		
		printf("X value : %d \\t Y value : %d \\n\\r",X_value,Y_value);
		_delay_ms(1000);
    }
}

ADC

• Signal Description

  

• Resister Summary

  

• ADC0_CTRLA

  

  

  • 10-bit resolution을 사용하고자 함.

    // 매크로 선언부
    #define _ADC0_CTRLA				(unsigned char *)(0x0600)
    #define _ADC_RESSEL_10BIT_gc	(0x01<<0)
    #define _ADC_ENABLE_bm			(0x01)    // adc enable(1: enable)
    #define _ADC_STCONV_bm			(0x01)    
    
    // ADC_init() 함수 정의 
    void ADC_init(void){
    	PORTD_PIN0CTRL = PORT_ISC_INPUT_DISABLE_gc;
    
    	ADC0_CTRLA = ADC_RESSEL_10BIT_gc;    // 10-bit resolution
    	ADC0_CTRLC |= ADC_REFSEL_VDDREF_gc;
    	ADC0_CTRLA |= ADC_ENABLE_bm | ADC_FREERUN_bm;
    }
    

• ADC0_CTRLC

  • ADC voltage reference로 VDD 이용

    // ADC_init() 함수 정의
    void ADC_init(void){
    	PORTD_PIN0CTRL = PORT_ISC_INPUT_DISABLE_gc;
    
    	ADC0_CTRLA = ADC_RESSEL_10BIT_gc;
    	ADC0_CTRLC |= ADC_REFSEL_VDDREF_gc;    // VDD 이용
    	ADC0_CTRLA |= ADC_ENABLE_bm | ADC_FREERUN_bm;
    }
    

• ADC0_MUXPOS

  

  • ADC에 연결된 single- ended analog input을 선택함.

  • ADC input pin 0 - 15 를 선택하고자함.

    → 각 ch에 맞는 입력 핀을 설정하도록 코드 작성

  #define _ADC0_MUXPOS			(unsigned char *)(0x0606)
  
  uint16_t ADC_read(int ch){    //  사용하고자 하는 핀 번호 - ch
  	ADC0_MUXPOS = ch;
  	ADC0_COMMAND |= ADC_STCONV_bm;
  	
  	while(!(ADC0_COMMAND) & ADC_STCONV_bm);
  	
  	return (uint16_t)ADC0_RES;
  }
  

• ADC0_RES

  • ADC 값 출력 레지스터
  • 10-bit 값을 출력하고자 함.

  

UART

• PUTTY - Serial 통신 session start (port 번호 입력 후)

  

• 10-bit 값으로 조이스틱 입력값이 출력되는 것을 확인할 수 있음.