/********************************************************************************
Serial communications to arduino for Toolerator3000 EMCO 120P lathe tool turret.
*********************************************************************************/

component toolerator3000            "Services an arduino based turret controller board for EMCOTurn 120P lathe";

pin in bit toolchange = false       "Receives signal from Linuxcnc M6 that tool change required";
pin in s32 toolnumber               "Receives data from Linuxcnc M6 Tx (tool no.) requested.";
pin out bit toolchanged = false     "Sends signal back to Linuxcnc when tool change finished";

option singleton yes;               // makes no sense to have more than one of these components running
option userspace yes;

// Adapted from serialcon2.comp by author "ArcEye arceyeATmgwareDOTcoDOTuk";
author "Tome tom-emcATbgpDOTnu";
license "GPL";
;;

#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>

#define BAUDRATE B9600 //#define BAUDRATE B115200
#define DEVICE "/dev/ttyUSB0" // IF THIS IS NOT THE DEVICE YOUR ARDUINO USES, CHANGE IT
#define _POSIX_SOURCE 1 /* POSIX compliant source */

int serialport_init();  // predef of later function
                             
struct termios toptions;; // port setup

void user_mainloop(void)
{
char buffer;
char ch;
int checked_toolnumber;
char myVersionBuffer[1024];
int  nReadCount;
int fd = serialport_init();
char once = 0;
int nReadCounter = 0;

user_mainloop_init:

    // read and discard 'T' return code from Toolerator3000 (if present), or any other leftover bytes
    while ( read( fd, myVersionBuffer, 1023) >= 1 ) 
        usleep(100000); 

    // send version request
    buffer = 'V';
    write( fd, &buffer, 1 );
   
    // wait for start of reply from toolerator3000
    int nBytesReady = 0;
    while (nBytesReady <= 0)
    {
        usleep(100000);
        ioctl(fd, FIONREAD, &nBytesReady );

        // if the reply is taking too long, resend the command
        if (nReadCounter++ > 30)
        {
            // report the error
            printf("Toolerator3000: Timeout, will retry version request\n");
            fflush(stdout);
            
            nReadCounter = 0;
            goto user_mainloop_init;
        }
    }

    // give a little extra time for the reply transmit to complete
    usleep(100000);
    
    // read the version string
    nReadCount = read( fd, myVersionBuffer, 1023); 
    
    // check if the Toolerator3000 was still booting, and sent the ready prompt (and ignored our version request)
    if (nReadCount <= 0 || (nReadCount == 1 && myVersionBuffer[0] == 'T'))
        goto user_mainloop_init;  // restart version request now that the Toolerator3000 is ready
    
    // display the version string
    myVersionBuffer[nReadCount] = 0; // guarantee string is null terminated
    printf("Toolerator3000 Firmware Version: %s\n", myVersionBuffer );
    fflush(stdout);
    
    while(fd != -1)
    {
        usleep(100000);
        FOR_ALL_INSTS()  
        { 
            if(toolchange) //tool change was requested
            {
                if (toolnumber >= 1)
                    checked_toolnumber = (toolnumber-1) % 8 + 1; //Convert tool number to mod-8 so will be always be 1-8
                    //this let's one have a tool table full of tools for multiple jobs while only using 8 actual tools
                else
                {
                    toolchanged = 1; //if tool number is 0 exit - ie, ignore that request
                    continue;
                }     
                
                if (!once)  //Only want to write our request to change tool one time
                {
                    // flush any extra bytes, possibly from a previous command or unexpected Toolerator3000 reboot
                    while ( read( fd, myVersionBuffer, 1023) >= 1 ) 
                        usleep(100000);
           
                    // only write command once
                    once = 1;
                    
                    // write the command
                    buffer = checked_toolnumber + '0';  //this ('0') causes toolnumber to be converted to ascii
                    write(fd, &buffer, 1);  //write tool number request to Toolerator
                }
                
                if (read(fd,&ch,1) == 1) //waiting for a return character from Toolerator
                {       
                    if(ch != buffer)  // if byte read doesn't match tool requested, fail
                    {
                       // force reissue command                      
                       once = 0; 
                       
                       // report error to stdout
                       printf ("Toolerator3000: invalid return code: %c\n", ch);  //something else came back
                       fflush(stdout);
                       
                    } else {
                       // success!
                       toolchanged = 1;
                    }
                }
            
            }
            else
            {
                once = 0;  //reset our one-time variable
                toolchanged=0; //reset toolchanged back to false to be ready for another request
            }
        }           
    }

    close(fd);
    exit(0);
}

//######################################################################

int serialport_init()
{
int fd;
 
    fd = open(DEVICE, 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 = BAUDRATE; 
    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] = 0;
    
    if( tcsetattr(fd, TCSANOW, &toptions) < 0) 
        {
        perror("init_serialport: Couldn't set term attributes");
        return -1;
        }
    tcflush(fd, TCIOFLUSH);
    return fd;
}