Wookie

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <termio.h>
#include <strings.h>
#define _POSIX_SOURCE 1

#define DATAPORT "/dev/ttyUSB0"
#define CONTROLPORT "/dev/ttyUSB1"
#define SLEEP_SHORT 100000
#define SLEEP_LONG 1000000

int data_fd, control_fd;

int open_port()
{
    // open the data channel
    data_fd = open(DATAPORT, O_RDWR  | O_NOCTTY | O_NDELAY);

    if (data_fd == -1) {
        printf("Error opening data channel!\n");
        exit(-1);
    } else {
        printf("Data channel open.\n");
    }

    // open the control channel
    control_fd = open(CONTROLPORT, O_RDWR | O_NOCTTY | O_NDELAY);

    if (control_fd == -1) {
        close(data_fd);
        printf("Error opening control channel!\n");
        exit(-1);
    } else {
        printf("Control channel open.\n");
    }
    return 0;
}

int init_port()
{
    // flush I/O buffers on both serial devices
    tcflush(data_fd, TCIOFLUSH);
    tcflush(control_fd, TCIOFLUSH);
    return 0;
}

int close_port()
{
    close(data_fd);
    close(control_fd);
    return 0;
}

#define RESET_COPYMODE 0
#define RESET_PLAYMODE 1
#define RESET_ALTPORT  2
#define RESET_NORESET  4

int reset_copy_nes(int mode)
{
    int status = 0;

    if(mode & RESET_PLAYMODE)
    {
        // clr /RTS=1
        ioctl(control_fd, TIOCMGET, &status);
        status &= ~TIOCM_RTS;
        ioctl(control_fd, TIOCMSET, &status);
    }
    else
    {
        // set /RTS=0
        ioctl(control_fd, TIOCMGET, &status);
        status |= TIOCM_RTS;
        ioctl(control_fd, TIOCMSET, &status);

    }


    if(!(mode & RESET_NORESET))
    {
        // pull /RESET low    clear D2
        // set /DTR=0
        ioctl(control_fd, TIOCMGET, &status);
        status &= ~TIOCM_DTR;
        ioctl(control_fd, TIOCMSET, &status);
        usleep(SLEEP_SHORT);
    }

    // pull /RESET high       set D2
    // clr /DTR=1
    ioctl(control_fd, TIOCMGET, &status);
    status |= TIOCM_DTR;
    ioctl(control_fd, TIOCMSET, &status);

    usleep(SLEEP_SHORT);
    init_port();
    usleep(SLEEP_SHORT);

    return 0;
}

int get_version()
{
    int bytes, i;
    unsigned char a = 0xA1;
    char buf[255];

    bytes = write(data_fd, &a, 1);

    if (bytes != 1) {
        printf("Error sending request: %d (%s)\n", bytes, strerror(errno));
        return -1;
    } else {
        usleep(SLEEP_SHORT);

        // zero out the buffer
        bzero(buf, 255);

        // read the bytes
        for(i = 0; i < 255; i++) {
            bytes = read(data_fd, &buf[i], 1);

            if(bytes <= 0)
                break;
        }

        // output the version string
        printf("Version: %s\n", buf);
        printf("bytes read: %d\n", i);
    }

    return 0;
}

int play_cart()
{
    reset_copy_nes(RESET_PLAYMODE);
    printf("Press enter when done playing.\n");
    getchar();
    reset_copy_nes(RESET_COPYMODE);
    return 0;
}

int main(int argc, char** argv)
{
    if(argc < 2)
    {
        printf("Usage: %s <version|play>\n", argv[0]);
        exit(0);
    }

    open_port();

    init_port();

    if(strcasecmp(argv[1], "version") == 0)
    {
        get_version();
    }
    else if(strcasecmp(argv[1], "play") == 0)
    {
        play_cart();
    }
    else
    {
        printf("unknown command\n");
    }

    // must clean up...
    close_port();
}