// code by SASANO Takayoshi, CC BY-SA

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <termios.h>
#include <fcntl.h>
#include <unistd.h>

#define BUFSIZE		256
#define CRLF		"\x0d\x0a"

#if 1
#define FONTSIZE	16
#define X_SIZE		160
#define Y_SIZE		128
#define DELAY		540000
#else
#define FONTSIZE	24
#define X_SIZE		320
#define Y_SIZE		240
#define DELAY		2600000
#endif

static	void	tx_test(int fd)
{
	unsigned int	i, n;
	uint8_t	buf[BUFSIZE], tmp[BUFSIZE];

	sprintf(buf, "RESET;" CRLF);
	write(fd, buf, strlen(buf));
	usleep(250000);

	sprintf(buf, "CLR(0);DIR(1);" CRLF);
	write(fd, buf, strlen(buf));
	usleep(250000);

	memset(tmp, ' ', sizeof(tmp));
	tmp[X_SIZE / (FONTSIZE / 2)] = '\0';

	for (n = 0;; n++) {
		sprintf(buf, "SBC(%d);", n & 3);
		write(fd, buf, strlen(buf));

		for (i = 0; i < Y_SIZE; i += FONTSIZE) {
			tmp[0] = ((n % 100) / 10) + '0';
			tmp[1] = (n % 10) + '0';
			sprintf(buf, "DCV%d(0,%d,'%s',15);", FONTSIZE, i, tmp);
			write(fd, buf, strlen(buf));
		}

		sprintf(buf, CRLF);
		write(fd, buf, strlen(buf));

		usleep(DELAY);
	}
}

static	int	setup_serial(int fd)
{
	struct termios	t;

	memset(&t, 0, sizeof(t));

	cfsetospeed(&t, 115200);
	cfsetispeed(&t, 115200);

	t.c_cflag = CREAD | CLOCAL | CS8;

	t.c_iflag = INPCK;
	t.c_oflag = 0;
	t.c_lflag = 0;

	t.c_cc[VTIME] = 0;
	t.c_cc[VMIN] = 1;

	tcflush(fd, TCIFLUSH);
	if (tcsetattr(fd, TCSANOW, &t) < 0) goto fail;

	return 0;
fail:
	return -1;
}

int	main(int argc, char *argv[])
{
	int	fd;

	if (argc < 2) {
		printf("%s [device]\n", argv[0]);
		goto fin0;
	}

	fd = open(argv[1], O_RDWR | O_NOCTTY);
	if (fd < 0) {
		printf("device open error\n");
		goto fin0;
	}

	if (setup_serial(fd) < 0) {
		printf("serial parameter error\n");
		goto fin1;
	}

	tx_test(fd);

fin1:
	close(fd);
fin0:
	return 0;
}