PIC32 - UART

초기화

//UART 관련 
void Init_uart()
{
	int pbClk = PBCLK;
	//시리얼 통신, 인터럽트 초기화
	
	OpenUART1(UART_EN, UART_RX_ENABLE | UART_TX_ENABLE, pbClk/16/DESIRED_BAUDRATE-1);
	ConfigIntUART1(UART_INT_PR5 | UART_RX_INT_EN);

	OpenUART2(UART_EN, UART_RX_ENABLE | UART_TX_ENABLE, pbClk/16/DESIRED_BAUDRATE-1);
	ConfigIntUART2(UART_INT_PR3 | UART_RX_INT_EN);
}

인터럽트 (UART2)

//UART2 인터럽트
void __ISR(_UART2_VECTOR, ipl3) _uart2(void) 	
{
	// Is this an RX interrupt? 
	if(INTGetFlag(INT_SOURCE_UART_RX(UART2)))
	{
		// Clear the RX interrupt Flag 
		INTClearFlag(INT_SOURCE_UART_RX(UART2));
		U2STAbits.OERR=0;

		g_RxData = UARTGetDataByte(UART2);
		//myprintf("[%c]\r\n", g_RxData );

		UARTGetDataByte(UART2);
	}

	// We don't care about TX interrupt
	if ( INTGetFlag(INT_SOURCE_UART_TX(UART2)) )
	{
		INTClearFlag(INT_SOURCE_UART_TX(UART2));
	}
}

myprintf 사용을 위한 추가 부분 (UART2)
myprintf는 vs등에서 printf와 같은 기능이 있다.
이 함수에서는 %d(decimal), %s(string), %c(char), %x, %X(hexadecimal), %u(long) 를 지원한다.
%f를 지원하지 않는게 참 아쉬울뿐이다.. 따로 만들어 쓰자.

static void printchar(char **str, int c)
함수의  else안에 c라는 char를 프린트 하는 함수를 넣어주면 된다.

PIC32MX460에서는

void PutCharacter(const char character);

void PutCharacter(const char character)
{
        while(!UARTTransmitterIsReady(UART2));
        UARTSendDataByte(UART2, character);
        while(!UARTTransmissionHasCompleted(UART2));
}

를 넣어주고

TMS320F2808 에서는

while (SciaRegs.SCIFFTX.bit.TXFFST != 0) {}

SciaRegs.SCITXBUF=c;

를 넣어주면 된다.
물론 해당 헤더를 include해야 한다.  

/*
	Copyright 2001, 2002 Georges Menie (www.menie.org)
	stdarg version contributed by Christian Ettinger

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
#include <plib.h>
#include "pic32_uart.h"
/*
	putchar is the only external dependency for this file,
	if you have a working putchar, leave it commented out.
	If not, uncomment the define below and
	replace outbyte(c) by your own function call.

#define putchar(c) outbyte(c)
*/

#include <stdarg.h>
void delay( unsigned int i)
{
	while(i--);
}
static void printchar(char **str, int c)
{
	extern int putchar(int c);
	
	if (str) {
		**str = c;
		++(*str);
	}
	else  
	{
//		while(U2STAbits.TRMT == 0);
//		U2TXREG = c;

		PutCharacter(c); //?

//		delay(100);	
	}
}

#define PAD_RIGHT 1
#define PAD_ZERO 2

static int prints(char **out, const char *string, int width, int pad)
{
	register int pc = 0, padchar = ' ';

	if (width > 0) {
		register int len = 0;
		register const char *ptr;
		for (ptr = string; *ptr; ++ptr) ++len;
		if (len >= width) width = 0;
		else width -= len;
		if (pad & PAD_ZERO) padchar = '0';
	}
	if (!(pad & PAD_RIGHT)) {
		for ( ; width > 0; --width) {
			printchar (out, padchar);
			++pc;
		}
	}
	for ( ; *string ; ++string) {
		printchar (out, *string);
		++pc;
	}
	for ( ; width > 0; --width) {
		printchar (out, padchar);
		++pc;
	}

	return pc;
}

/* the following should be enough for 32 bit int */
#define PRINT_BUF_LEN 12

static int printi(char **out, int i, int b, int sg, int width, int pad, int letbase)
{
	char print_buf[PRINT_BUF_LEN];
	register char *s;
	register int t, neg = 0, pc = 0;
	register unsigned int u = i;

	if (i == 0) {
		print_buf[0] = '0';
		print_buf[1] = '\0';
		return prints (out, print_buf, width, pad);
	}

	if (sg && b == 10 && i < 0) {
		neg = 1;
		u = -i;
	}

	s = print_buf + PRINT_BUF_LEN-1;
	*s = '\0';

	while (u) {
		t = u % b;
		if( t >= 10 )
			t += letbase - '0' - 10;
		*--s = t + '0';
		u /= b;
	}

	if (neg) {
		if( width && (pad & PAD_ZERO) ) {
			printchar (out, '-');
			++pc;
			--width;
		}
		else {
			*--s = '-';
		}
	}

	return pc + prints (out, s, width, pad);
}

static int print( char **out, const char *format, va_list args )
{
	register int width, pad;
	register int pc = 0;
	char scr[2];

	for (; *format != 0; ++format) {
		if (*format == '%') {
			++format;
			width = pad = 0;
			if (*format == '\0') break;
			if (*format == '%') goto out;
			if (*format == '-') {
				++format;
				pad = PAD_RIGHT;
			}
			while (*format == '0') {
				++format;
				pad |= PAD_ZERO;
			}
			for ( ; *format >= '0' && *format <= '9'; ++format) {
				width *= 10;
				width += *format - '0';
			}
			if( *format == 's' ) {
				register char *s = (char *)va_arg( args, int );
				pc += prints (out, s?s:"(null)", width, pad);
				continue;
			}
			if( *format == 'd' ) {
				pc += printi (out, va_arg( args, int ), 10, 1, width, pad, 'a');
				continue;
			}
			if( *format == 'x' ) {
				pc += printi (out, va_arg( args, int ), 16, 0, width, pad, 'a');
				continue;
			}
			if( *format == 'X' ) {
				pc += printi (out, va_arg( args, int ), 16, 0, width, pad, 'A');
				continue;
			}
			if( *format == 'u' ) {
				pc += printi (out, va_arg( args, int ), 10, 0, width, pad, 'a');
				continue;
			}
			if( *format == 'c' ) {
				/* char are converted to int then pushed on the stack */
				scr[0] = (char)va_arg( args, int );
				scr[1] = '\0';
				pc += prints (out, scr, width, pad);
				continue;
			}
		}
		else {
		out:
			printchar (out, *format);
			++pc;
		}
	}
	if (out) **out = '\0';
	va_end( args );
	return pc;
}

int myprintf(const char *format, ...)
{
        va_list args;
        
        va_start( args, format );
        return print( 0, format, args );
}

int sprintf(char *out, const char *format, ...)
{
        va_list args;
        
        va_start( args, format );
        return print( &out, format, args );
}


int snprintf( char *buf, unsigned int count, const char *format, ... )
{
        va_list args;
        
        ( void ) count;
        
        va_start( args, format );
        return print( &buf, format, args );
}

#define TEST_PRINTF
#ifdef TEST_PRINTF

/*
 * if you compile this file with
 *   gcc -Wall $(YOUR_C_OPTIONS) -DTEST_PRINTF -c printf.c
 * you will get a normal warning:
 *   printf.c:214: warning: spurious trailing `%' in format
 * this line is testing an invalid % at the end of the format string.
 *
 * this should display (on 32bit int machine) :
 *
 * Hello world!
 * printf test
 * (null) is null pointer
 * 5 = 5
 * -2147483647 = - max int
 * char a = 'a'
 * hex ff = ff
 * hex 00 = 00
 * signed -3 = unsigned 4294967293 = hex fffffffd
 * 0 message(s)
 * 0 message(s) with %
 * justif: "left      "
 * justif: "     right"
 *  3: 0003 zero padded
 *  3: 3    left justif.
 *  3:    3 right justif.
 * -3: -003 zero padded
 * -3: -3   left justif.
 * -3:   -3 right justif.
 */

#endif


/* To keep linker happy. */
int	write( int i, char* c, int n)
{
	return 0;
}

자이로 센서는 UART1을 사용한다.
Baudrate은 115200 //
각속도를 알려주는 것이 아니라 각도 값을 실시간으로 보내준다.
Data를 계속 떤지기 때문에 Rx 버퍼가 가득 차 버릴 수 있다.
PIC32에서는 이 경우 에러 플래그를 초기화해주지 않을 경우 UART모듈이 멈춰버린다.
(이 이를 알기까지 얼마나 어려웠는데..-_-)
U1STAbits.OERR=0;
를 인터럽트 루틴 안에서 꼭 호출 해 줘야 한다.

자이로 센서의 경우 UART의 Rx만 사용하기 때문에 Tx는 다른 용도로 사용할 수 있다.

자이로 센서 (UART1)

//UART1 인터럽트 -> 자이로 
void __ISR(_UART1_VECTOR, ipl5) _uart1(void) 
{
	unsigned int uCheckSum;
	unsigned int uTmp;
	unsigned char arr[2] = {0, '\0'};



	// Is this an RX interrupt?
	if(INTGetFlag(INT_SOURCE_UART_RX(UART1)))
	{
		// Clear the RX interrupt Flag
		INTClearFlag(INT_SOURCE_UART_RX(UART1));
		U1STAbits.OERR=0;
		
//		if(U1STAbits.OERR) 
//		{
//			U1STAbits.OERR=0;
//		}
		


//*
		if(g_GyroFlag != 0)	
		{//자이로 각도 계산 		
			byRxChar = UARTGetDataByte(UART1);

//			myprintf( "_%c", byRxChar);

			if(g_GyroFlag == 1)
			{
				if(byRxChar == 0xff)
				{
					g_GyroFlag = 2;	
					myprintf(" start \r\n", arr);		
				}
				else
				{
					arr[0] = byRxChar;
					myprintf("%c", byRxChar);
				}
			}
			if(g_ByRxRemainder >= 2)
			{
				m_aGyroBuf[g_ByRxRemainder] = byRxChar;
				g_ByRxRemainder += 1;
				if(g_ByRxRemainder >= 8)
				{
	           			g_ByRxRemainder = 0;
					uCheckSum = (m_aGyroBuf[1] << 8) | m_aGyroBuf[0];
					uCheckSum += (m_aGyroBuf[3] << 8) | m_aGyroBuf[2];
					uCheckSum += (m_aGyroBuf[5] << 8) | m_aGyroBuf[4];
	            
					if ((uCheckSum & 0xFFFF) == (unsigned int)((m_aGyroBuf[7] << 8) | m_aGyroBuf[6]))
					{
						uTmp = m_aGyroBuf[5];
						uTmp = ((uTmp << 8) & 0xff00) | m_aGyroBuf[4];
					// agnle : -180 ~ 180 도 까지 출력.
					// m_aGyroBuf[5]는 상위 비트임.
					//
					// 0~180도는 1~18000  => Hex 0~4650
					// -180~0도는 47536~65536 가지 나옴. => Hex B9B0 ~ FFFF
					// 그러므로 47536(B9B0)에서 제일 처음 비트가 1이 셋 되면
					// 음수의 각도를 나타내므로 제일 처음 비트를 검사한다.
					// B9B0 의 B => 1011 bit임.
					// 4650 의 4 => 0100 bit임.
					// 따라서 최상위 숫자의 제일 상위 비트만으로도 구분 가능함.
						if (m_aGyroBuf[5] & 0x80)
						{
							g_Gyro = 360.0 - ((65536 - uTmp)/100.0);
							//g_Gyro = 360.0 - ((65536 - uTmp)/10.0);
						}
						else
						{
							g_Gyro = uTmp / 100.0;
							//g_Gyro = uTmp / 10.0;
						}

						if(g_GyroFlag < 10) g_GyroFlag++;									
					}
				}
			}
			else
			{
				if (byRxChar == 0xFF)
				{
					m_aGyroBuf[g_ByRxRemainder] = byRxChar;
					g_ByRxRemainder += 1;
				}
				else
				{
					g_ByRxRemainder = 0;
				}
	    		}
		}
		else
		{
			int temp = 0;
			if(temp) temp = 1;
			g_byCommand = UARTGetDataByte(UART1);
		}

//*/

	}

	// We don't care about TX interrupt
	if ( INTGetFlag(INT_SOURCE_UART_TX(UART1)) )
	{
		INTClearFlag(INT_SOURCE_UART_TX(UART1));
	}
}