/*

* Arduino-serial

* --------------

*

* A simple command-line example program showing how a computer can

* communicate with an Arduino board. Works on any POSIX system (Mac/Unix/PC)

*

*

* Compile with something like:

* gcc -o arduino-serial arduino-serial.c

*

* Created 5 December 2006

* Copyleft (c) 2006, Tod E. Kurt, tod@todbot.com

*

*

*

* Updated 8 December 2006:

*  Justin McBride discoevered B14400 & B28800 aren't in Linux's termios.h.

*  I've included his patch, but commented out for now.  One really needs a

*  real make system when doing cross-platform C and I wanted to avoid that

*  for this little program. Those baudrates aren't used much anyway. :)

*

* Updated 26 December 2007:

*  Added ability to specify a delay (so you can wait for Arduino Diecimila)

*  Added ability to send a binary byte number

*

*/



#include <stdio.h>    /* Standard input/output definitions */

#include <stdlib.h>

#include <stdint.h>   /* Standard types */

#include <string.h>   /* String function definitions */

#include <unistd.h>   /* UNIX standard function definitions */

#include <fcntl.h>    /* File control definitions */

#include <errno.h>    /* Error number definitions */

#include <termios.h>  /* POSIX terminal control definitions */

#include <sys/ioctl.h>

#include <getopt.h>



void usage(void);

int serialport_init(const char* serialport, int baud);

int serialport_writebyte(int fd, uint8_t b);

int serialport_write(int fd, const char* str);

int serialport_read_until(int fd, char* buf, char until);



void usage(void) {

   printf("Usage: arduino-serial -p <serialport> [OPTIONS]\n"

   "\n"

   "Options:\n"

   "  -h, --help                   Print this help message\n"

   "  -p, --port=serialport        Serial port Arduino is on\n"

   "  -b, --baud=baudrate          Baudrate (bps) of Arduino\n"

   "  -s, --send=data              Send data to Arduino\n"

   "  -r, --receive                Receive data from Arduino & print it out\n"

   "  -n  --num=num                Send a number as a single byte\n"

   "  -d  --delay=millis           Delay for specified milliseconds\n"

   "\n"

   "Note: Order is important. Set '-b' before doing '-p'. \n"

   "      Used to make series of actions:  '-d 2000 -s hello -d 100 -r' \n"

   "      means 'wait 2secs, send 'hello', wait 100msec, get reply'\n"

   "\n");

}



int main(int argc, char *argv[])

{

   int fd = 0;

   char serialport[256];

   int baudrate = B115200;  // default

   char buf[20], dat[20], use[1];

   int rc,n;



     //baudrate = 9600;

     fd = serialport_init("/dev/ttyACM0", baudrate);

                 if(fd==-1) return -1;

     usleep(3000 * 1000 );



     while(1) {

           strcpy(dat, "00000000:\0");

           gets(use);

           if(use[0] == 'i') {

                 dat[0] = 'f';

                 dat[1] = 5;

           }

           else if(use[0] == 'k') {

                 dat[0] = 'b';

                 dat[1] = 5;

           }

           else if(use[0] == 'j') {

                 dat[2] = 'f';

                 dat[3] = 5;

           }

           else if(use[0] == 'l') {

                 dat[2] = 'b';

                 dat[3] = 5;

           }



           rc = serialport_write(fd, dat);

                       if(rc==-1) return -1;

            //printf("Waiting until UART buffer clears: %d\n", tcdrain(fd));

            n = serialport_read_until(fd, buf, ':');

              printf("wrote %d bytes, read %d bytes: %s\n", rc, n, buf);

     }



      close(fd);



   exit(EXIT_SUCCESS);

} // end main



int serialport_writebyte( int fd, uint8_t b)

{

   int n = write(fd,&b,1);

   if( n!=1)

       return -1;

   return 0;

}



int serialport_write(int fd, const char* str)

{

   int len = strlen(str);

   int n = write(fd, str, len);

   if( n!=len )

       return -1;

   return n;

}



int serialport_read_until(int fd, char* buf, char until)

{

   char b[1];

   int i=0;

   do {

       int n = read(fd, b, 1);  // read a char at a time

       if( n==-1) return -1;    // couldn't read

       if( n==0 ) {

           usleep( 10 * 1000 ); // wait 10 msec try again

           continue;

       }

       buf[i] = b[0]; i++;

   } while( b[0] != until );



   buf[i] = 0;  // null terminate the string

   return i;

}



// takes the string name of the serial port (e.g. "/dev/tty.usbserial","COM1")

// and a baud rate (bps) and connects to that port at that speed and 8N1.

// opens the port in fully raw mode so you can send binary data.

// returns valid fd, or -1 on error

int serialport_init(const char* serialport, int baud)

{

   struct termios toptions;

   int fd;



   //fprintf(stderr,"init_serialport: opening port %s @ %d bps\n",

   //        serialport,baud);



   //fd = open(serialport, O_RDWR | O_NOCTTY | O_NDELAY);

   fd = open(serialport, O_RDWR | O_NOCTTY);

   if (fd == -1)  {

       perror("init_serialport: Unable to open port ");

       return -1;

   }



   if (tcgetattr(fd, &toptions) < 0) {

       perror("init_serialport: Couldn't get term attributes");

       return -1;

   }

   speed_t brate = baud; // let you override switch below if needed

   switch(baud) {

   case 4800:   brate=B4800;   break;

   case 9600:   brate=B9600;   break;

// if you want these speeds, uncomment these and set #defines if Linux

//#ifndef OSNAME_LINUX

//    case 14400:  brate=B14400;  break;

//#endif

   case 19200:  brate=B19200;  break;

//#ifndef OSNAME_LINUX

//    case 28800:  brate=B28800;  break;

//#endif

   //case 28800:  brate=B28800;  break;

   case 38400:  brate=B38400;  break;

   case 57600:  brate=B57600;  break;

   case 115200: brate=B115200; break;

   }

   cfsetispeed(&toptions, brate);

   cfsetospeed(&toptions, brate);



   // 8N1

   toptions.c_cflag &= ~PARENB;

   toptions.c_cflag &= ~CSTOPB;

   toptions.c_cflag &= ~CSIZE;

   toptions.c_cflag |= CS8;

   // no flow control

   toptions.c_cflag &= ~CRTSCTS;



   toptions.c_cflag |= CREAD | CLOCAL;  // turn on READ & ignore ctrl lines

   toptions.c_iflag &= ~(IXON | IXOFF | IXANY); // turn off s/w flow ctrl



   toptions.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // make raw

   toptions.c_oflag &= ~OPOST; // make raw



   // see: http://unixwiz.net/techtips/termios-vmin-vtime.html

   toptions.c_cc[VMIN]  = 0;

   toptions.c_cc[VTIME] = 20;



   if( tcsetattr(fd, TCSANOW, &toptions) < 0) {

       perror("init_serialport: Couldn't set term attributes");

       return -1;

   }



   return fd;

}