xpt.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>
#include <wiringPi.h>
#include <wiringPiSPI.h>
#include "xpt2046.h"

#define SPI_CHANNEL 0 // /dev/spidev0.0
//#define SPI_CHANNEL 1 // /dev/spidev0.1
#define GPIO_PEN 6
#define CALIBRATIO 0

int main (int argc, char **argv){
	int x, y;
	int xpos, ypos;
	int pen_irq;

	if (wiringPiSPISetup(SPI_CHANNEL, 500000) < 0) {
		printf("wiringPiSPISetup failed:\n");
		return -1;
	}

	if (wiringPiSetup() < 0) {
		printf("wiringPiSetup failed:\n");
		return -1;
	}
	pinMode(GPIO_PEN,INPUT);

#if(CALIBRATIO)
	int xmin=99999;
	int xmax=0;
	int ymin=99999;
	int ymax=0;
#endif

	for (;;) {
		usleep(10000);	/* do it anyway ; settle time when pen goes up */
		pen_irq = digitalRead(GPIO_PEN);
		if (pen_irq == LOW)	{ /* PenIRQ is LOW : touch! pen is down */
			// Get physically position
			xptGetxy(SPI_CHANNEL, &x, &y);
			// Get scrren position
			xpos = xptScrren(x);
			ypos = yptScrren(y);
			printf("touch !! x=%5d(%3d) y=%5d(%3d)\n", x, xpos, y, ypos);

#if(CALIBRATIO)
			if (xmin > x) xmin=x;
			if (xmax < x) xmax=x;
			if (ymin > y) ymin=y;
			if (ymax < y) ymax=y;
			printf("touch !! xmin=%5d xmax=%5d\n", xmin, xmax);
			printf("touch !! ymin=%5d ymax=%5d\n", ymin, ymax);
#endif

		} else { /* pen is up */

		}
	} // end for

}