CSC231 Arduino-serial.c
/*
* 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
* http://todbot.com/blog/
*
*
* 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
*
* Update 31 August 2008:
* Added patch to clean up odd baudrates from Andy at hexapodia.org
*
* Modified 11/06/08 by D. Thiebaut
* Force program to wait until a \n is received from Arduino
* Added linking with assembly program
*/
#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>
//extern int asm_main( void );
//-------------------------- prototypes ---------------------------
void usage(void);
int serialport_init(const char* serialport, int baud);
int serialport_writebyte( );
int serialport_write( );
int serialport_read_until( );
int displayBuffer( );
//---------------------------- globals ----------------------------
int fd = 0; // file descriptor for USB device
char serialport[256]; // name of the serial port (/dev/ttyUSB0)
int baudrate = B9600; // default baud rate
char buf[1024]; // buffer for sent/receive strings
uint8_t byte;
int pin;
//-----------------------------------------------------------------
//-----------------------------------------------------------------
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 rc, n;
if (argc==1) {
usage();
exit(EXIT_SUCCESS);
}
/*--- parse options ---*/
int option_index = 0, opt;
static struct option loptions[] = {
{"help", no_argument, 0, 'h'},
{"port", required_argument, 0, 'p'},
{"baud", required_argument, 0, 'b'},
{"send", required_argument, 0, 's'},
{"receive", no_argument, 0, 'r'},
{"num", required_argument, 0, 'n'},
{"delay", required_argument, 0, 'd'}
};
/*--- process the command line arguments ---*/
while(1) {
opt = getopt_long ( argc, argv, "hp:b:s:rn:d:",
loptions, &option_index );
if (opt==-1) break;
switch (opt) {
case '0': break;
case 'd':
n = strtol(optarg,NULL,10);
usleep(n * 1000 ); // sleep milliseconds
break;
case 'h':
usage();
break;
case 'b':
baudrate = strtol(optarg,NULL,10);
break;
case 'p':
strcpy(serialport,optarg);
fd = serialport_init( optarg, baudrate );
if(fd==-1){
printf( "Could not initialize USB port\n\n" );
return -1;
}
break;
case 'n':
n = strtol(optarg, NULL, 10 ); // convert string to number
byte = (uint8_t) n;
rc = serialport_writebyte( );
if(rc==-1) return -1;
break;
case 's':
strcpy( buf, optarg );
rc = serialport_write( );
if (rc==-1) return -1;
break;
case 'r':
serialport_read_until( );
printf("%s\n",buf);
break;
}
}
//--- call assembly language program ---
//asm_main();
//--- exit ---
exit(EXIT_SUCCESS);
} // end main
//-----------------------------------------------------------------
//-----------------------------------------------------------------
int displayBuffer( ) {
printf( "buffer = [%s]\n", buf );
return 0;
}
//-----------------------------------------------------------------
//-----------------------------------------------------------------
int serialport_writebyte( ) {
int n = write( fd, &byte, 1);
if( n!=1)
return -1;
return 0;
}
//-----------------------------------------------------------------
//-----------------------------------------------------------------
int serialport_write() {
int len;
strcat( buf, "\n" );
len = strlen(buf);
int n = write( fd, buf, len );
if( n!=len )
return -1;
return 0;
}
//-----------------------------------------------------------------
//-----------------------------------------------------------------
int serialport_read_until( ) {
char b[1];
int i=0, k;
do {
int n = read(fd, b, 1); // read a char at a time
if( n==-1) {
usleep( 100*1000 );
continue;
}
if( n==0 ) {
usleep( 10 * 1000 ); // wait 10 msec try again
continue;
}
buf[i] = b[0];
i++;
} while( b[0] != '\n' );
buf[i] = 0; // null terminate the string
return 0;
}
//-----------------------------------------------------------------
// 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);
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;
#ifdef B14400
case 14400: brate=B14400; break;
#endif
case 19200: brate=B19200; break;
#ifdef B28800
case 28800: brate=B28800; break;
#endif
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;
}
