리눅스에서 조이스틱 값 읽어오기

CCTV(PTZ) 업체에 있다 보니 리눅스에서도 조이스틱을 이용해서
컨트롤러를 대체할수 있을까 라는 생각에 조이스틱 관련 API를 찾아보는데
의외로 단순한 구조 같은 느낌..

요즘에는 USB로도 많이 쓰니 USB목록에서 장치명을 찾아서 열거하는 것도 필요할 듯 하고
아무튼 중요한건 js_event 구조체 이녀석인듯.

int fd = open ("/dev/js0", O_RDONLY); struct js_event e; read (fd, &e, sizeof(struct js_event)); struct js_event { __u32 time;     /* event timestamp in milliseconds */ __s16 value;    /* value */ __u8 type;      /* event type */ __u8 number;    /* axis/button number */ };

[링크 : http://www.mjmwired.net/kernel/Documentation/input/joystick-api.txt] 3.2 kernel
[링크 :  http://archives.seul.org/linuxgames/Aug-1999/msg00107.html] 2.2 kernel

----
curse.h가 없다고 에러날 경우는 아래와 같이 설치해주고

$ sudo apt-get install libncurses5-dev

소스는 이런식으로 수정하고 컴파일을 하면된다.

#define JOY_DEV "/dev/input/js0"

#include "pthread.h"
#include "sys/timeb.h"
#include "curses.h"
#include "fcntl.h"
#include "linux/joystick.h"

#define NUM_THREADS	3
#define JOY_DEV		"/dev/input/js0"
#define HZ				12

const char FILENAME[] = "./joystickLog.out";
char axisDesc[15][5] = {"X", "Y", "Z", "R", "A", "B", "C", "D", "E", "F", "G", "H", "I" };
char numAxis[20], numButtons[20], value[20][20], timeSec[20], timeMilli[20];
int num_of_axis;

void write_to_log(){
	sleep(1);
	int cnt;
	FILE * daFile;
	daFile = fopen(FILENAME, "w+");

//	WRITE A HEADER ON THE OUPUT FILE
	fprintf(daFile, "#,");
	for(cnt = 0; cnt < num_of_axis; cnt++)
		if(cnt < num_of_axis -1)	fprintf(daFile, "%s,", axisDesc[cnt]);
		else								fprintf(daFile, "%s", axisDesc[cnt]);
	fprintf(daFile, "\r\n");

	while(1){
		fprintf(daFile, "%s.%s, ", timeSec, timeMilli);
		for(cnt = 0; cnt < num_of_axis; cnt++){
			if(cnt < num_of_axis -1)	fprintf(daFile, "%s, ", value[cnt]);
			else								fprintf(daFile, "%s ", value[cnt]);
		}
		fprintf(daFile, "\r\n");
		usleep(83333);
	}
	
	fprintf(daFile, "%s.%s Len = %d ", timeSec, timeMilli,strlen(timeMilli));

	fprintf(daFile, "\r\n");
	fflush(daFile);
}

void write_to_screen(){
	struct timeb seconds;
	int cnt, joy_fd, *axis=NULL, num_of_buttons=0, x;
	char *button=NULL, name_of_joystick[80];
	struct js_event js;
	time_t theTime;

	wmove(stdscr, 8, 0);
	addstr("Type \"q\" to quit.\n");

	if( ( joy_fd = open( JOY_DEV , O_RDONLY)) == -1 ){
		wmove(stdscr, 3,0);
		addstr( "Couldn't open joystick " );
		addstr( JOY_DEV );
		wmove(stdscr, 10,0);
		while(1)usleep(16666);
	}

	ioctl( joy_fd, JSIOCGAXES, &num_of_axis );				//	GET THE NUMBER OF AXIS ON JS
	ioctl( joy_fd, JSIOCGBUTTONS, &num_of_buttons );		//	GET THE NUMBER OF BUTTONS ON THE JS
	ioctl( joy_fd, JSIOCGNAME(80), &name_of_joystick );	//	GET THE NAME OF THE JS

	axis = (int *) calloc( num_of_axis, sizeof( int ) );
	button = (char *) calloc( num_of_buttons, sizeof( char ) );

	sprintf(numAxis, "%d", num_of_axis);
	sprintf(numButtons, "%d", num_of_buttons);

	wmove(stdscr, 0,0);
	addstr("Joystick detected: ");

	wmove(stdscr, 0, 19);
	addstr(name_of_joystick);

	wmove(stdscr, 1, 0);
	addstr("Number of axis   :");

	wmove(stdscr, 1, 19);
	addstr(numAxis);
	
	wmove(stdscr, 2, 0);
	addstr("Number of buttons:");

	wmove (stdscr, 2, 19);
	addstr(numButtons);

//	CHANGE THE STATUS FLAG OF THE FILE DESCRIPTOR TO NON-BLOCKING MODE
	fcntl( joy_fd, F_SETFL, O_NONBLOCK );   

	while( 1 ){
		usleep(16666);
	
	//	READ THE JOYSTICK STATE, IT WILL BE RETURNED IN THE JS_EVENT STRUCT
		read(joy_fd, &js, sizeof(struct js_event));

	//	GET THE NUMBER OF SECONDS SINCE EPOCH
		ftime(&seconds);
		theTime = time(NULL);
		sprintf(timeSec, "%d", seconds.time);						
		sprintf(timeMilli, "%d", seconds.millitm);
               
	//	CHECK THE EVENT
		switch (js.type & ~JS_EVENT_INIT){
			case JS_EVENT_AXIS:
				axis   [ js.number ] = js.value;
				break;
			case JS_EVENT_BUTTON:
				button [ js.number ] = js.value;
				break;
		}
		//	ADD LEADING 0'S TO THE MILLISECOND STRING (IF NECESSARY)
			char temp[10] = "";
			while(strlen(temp) < (3 - strlen(timeMilli)))
				strcat(temp, "0");
			strcat(temp,timeMilli);
			strcpy(timeMilli, temp);

		//	PRINT THE RESULTS
			wmove(stdscr, 4, 0);
			for(cnt = 0; cnt < num_of_axis; cnt++)
				addstr("            ");
			for(cnt = 0; cnt < num_of_axis && cnt < 13; cnt++){
				sprintf(value[cnt], "%d", axis[cnt]);
				wmove(stdscr, 4, cnt * 10);
				addstr(axisDesc[cnt]);
				addstr(": ");
				wmove(stdscr, 4, (cnt * 10) + 2);
				addstr(value[cnt]);
			}
			
			wmove(stdscr, 6, 0);
			addstr(timeSec);
			wmove(stdscr, 6,10);
			addstr(".");
			wmove(stdscr, 6, 11);
			addstr(timeMilli);
			wmove(stdscr, 6, 15);
			addstr("=");
			wmove(stdscr, 6, 17);
			addstr(ctime(&theTime));
                       
			wmove(stdscr, 10, 0);
			refresh();
	}
}

void *ThreadProcs(void *threadid){
	int thread_id = (int)threadid;
	
	if(thread_id == 0){
		write_to_screen();
	}
	
	if(thread_id == 1){
	//	THIS THREAD WILL MAKE THE PROGRAM EXIT
		int ch;
		nodelay(stdscr, TRUE);				//	SETUP NON BLOCKING INPUT
		while(1) {
			if ((ch = getch()) == ERR) usleep(16666);		//	USER HASN'T RESPONDED
			else if( ch == 'q'){			
				endwin();
				exit(0);			//	QUIT ALL THREADS
			}
		}
	}
	if(thread_id == 2){
		write_to_log();
	}
}

int main(int argc, char *argv[]){
	initscr(); 									//	INIT THE SCREEN FOR CURSES
	pthread_t threads[NUM_THREADS];
	int rc, t;
	for(t = 0; t < NUM_THREADS; t++){	//	MAKE 2 NEW THREADS
		rc = pthread_create(&threads[t], NULL, ThreadProcs, (void *)t);
		if (rc){
			printf("ERROR; return code from pthread_create() is %d\n", rc);
			exit(-1);pthread_exit(NULL);
		}
	}
	
	for(t = 0; t < NUM_THREADS; t++)
		pthread_join(threads[t], NULL);		//	WAIT FOR THREADS TO EXIT OR IT WILL RACE TO HERE.

	endwin();
	return 0;
}

[링크 : http://www.linuxquestions.org/questions/programming-9/joystick-347292/]
 + [링크 : http://sukwoo.blogspot.com/2008/07/ubuntu-804-ncurses.html]
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[링크 : http://msdn.microsoft.com/en-us/library/windows/desktop/dd743596(v=vs.85).aspx] << 윈도우용