main.cpp

00001 /*
00002  * main.cpp
00003  *
00004  * Copyright (c) 2011 Peter Brier
00005  *
00006  *   This file is part of the LaOS project (see: http://wiki.protospace.nl/index.php/LaOS)
00007  *
00008  *   LaOS is free software: you can redistribute it and/or modify
00009  *   it under the terms of the GNU General Public License as published by
00010  *   the Free Software Foundation, either version 3 of the License, or
00011  *   (at your option) any later version.
00012  *
00013  *   LaOS is distributed in the hope that it will be useful,
00014  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00016  *   GNU General Public License for more details.
00017  *
00018  *   You should have received a copy of the GNU General Public License
00019  *   along with LaOS.  If not, see <http://www.gnu.org/licenses/>.
00020  *
00021  * This program implements Bresenham line algorithm program (2D)
00022  * see: http://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm
00023  * In addition: we controll a Z-axis and a laser.
00024  * Note: Fixed speed lasering (no accelleration).
00025  * Simple program, no line buffering. Considerable jitter on pulses. Speed varies approx 30%, depending on angle (varies over 1.5 degree)
00026  *
00027  */
00028 #include "mbed.h"
00029 
00030 // serial comm
00031 Serial pc(USBTX, USBRX); 
00032 
00033 // status leds
00034 DigitalOut led1(LED1);
00035 DigitalOut led2(LED2);
00036 DigitalOut led3(LED3);
00037 DigitalOut led4(LED4);
00038 
00039 // motors
00040 DigitalOut xdir(p26);
00041 DigitalOut xstep(p25);
00042 DigitalOut ydir(p24);
00043 DigitalOut ystep(p23);
00044 DigitalOut zdir(p22);
00045 DigitalOut zstep(p21);
00046 
00047 // laser
00048 DigitalOut laser(p27);
00049 
00050 // globals
00051 Ticker ticker;  // Timer
00052 
00053 // Besenham variables
00054 int state, laseron;
00055 int x0,y0,x1,y1,z0,z1;  // positions: 0=current, 1=new
00056 int dx, sx; // step
00057 int dy, sy;  // delta
00058 int err, e2; // error
00059 
00060 
00061 /**
00062 *** ticker: implement timer ticker, step if required
00063 **/
00064 void tick() 
00065 {
00066   // Control X,Y: line tracker
00067   switch ( state )
00068   {
00069     case 0: // idle (make sure laser is off)
00070       laser = laseron =  0;
00071       break;
00072     case 1: // init
00073       dx = abs(x1-x0);
00074       sx = x0<x1 ? 1 : -1;
00075       dy = abs(y1-y0);
00076       sy = y0<y1 ? 1 : -1; 
00077       err = (dx>dy ? dx : -dy)/2;
00078       xdir = sx > 0;
00079       ydir = sy > 0;
00080       state++;
00081       laser = laseron;
00082       break;
00083     case 2: // moving
00084       if (x0==x1 && y0==y1) 
00085         state = 0;
00086       else
00087       {
00088         e2 = err;
00089         if (e2 >-dx) { err -= dy; x0 += sx; xstep = 1;}
00090         if (e2 < dy) { err += dx; y0 += sy; ystep = 1;}
00091       }
00092       break;
00093   }
00094   
00095   // Controll Z: tracking controller (independent of XY motion, not queued)
00096   if ( z1 != z0 ) 
00097   {
00098     zdir = z1 > z0;
00099     wait_us(5);
00100     zstep= 1;
00101     if ( z1 > z0 ) z0++;
00102     else z0--;
00103   }
00104   
00105   if ( xstep == 1 || ystep == 1 || zstep == 1 )
00106   {
00107     wait_us(5);
00108     xstep = ystep = zstep = 0;
00109   }
00110   
00111   // diagnostic info
00112   led1 = xdir;
00113   led2 = ydir;
00114   led3 = zdir;
00115   led4 = laser;
00116 } // ticker
00117 
00118 
00119 
00120 /**
00121 *** main()
00122 *** Read commands, report state
00123 **/
00124 int main() 
00125 {
00126   int v=100,c=0,z=0;
00127 
00128   pc.baud(115200);  
00129   ticker.attach_us(&tick, v); // the address of the function to be attached (flip) and the interval (microseconds)
00130 
00131   // init
00132   state = laser = xstep = xdir = ystep = ydir = zstep = zdir = 0;
00133   
00134   while( 1 )
00135   {    
00136      scanf("%d", &c); 
00137      switch( c )
00138      {
00139           case 0: // move x,y (laser off)
00140             scanf("%d %d", &x1, &y1);
00141             laseron = 0;
00142             state = 1; 
00143             break;
00144           case 1: // line x,y (laser on)
00145             scanf("%d %d", &x1, &y1);
00146             laseron = 1;
00147             state = 1; 
00148             break;
00149           case 2: // move z 
00150             scanf("%d", &z1); 
00151             break;
00152           case 3: // set t (1/v)
00153             scanf("%d", &v);
00154             ticker.attach_us(&tick, v);
00155             break;
00156          case 4: // set x,y,z absolute
00157             scanf("%d %d %d", &x0, &y0, &z);
00158             z1 = z0 = z;
00159          case 5: // nop
00160            break;
00161          default: // I do not understand: stop motion
00162             state = 0;
00163           break;
00164     }
00165     printf("%d %d %d %d %d %d\r\n", state, x0, y0, z0, v, laseron);
00166   }
00167 }