stepper.h

00001 /*
00002   stepper.h - stepper motor driver: executes motion plans of planner.c using the stepper motors
00003   Part of Grbl
00004 
00005   Copyright (c) 2009-2011 Simen Svale Skogsrud
00006 
00007   Grbl is free software: you can redistribute it and/or modify
00008   it under the terms of the GNU General Public License as published by
00009   the Free Software Foundation, either version 3 of the License, or
00010   (at your option) any later version.
00011 
00012   Grbl is distributed in the hope that it will be useful,
00013   but WITHOUT ANY WARRANTY; without even the implied warranty of
00014   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015   GNU General Public License for more details.
00016 
00017   You should have received a copy of the GNU General Public License
00018   along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
00019 */
00020 
00021 #ifndef stepper_h
00022 #define stepper_h 
00023 
00024 // from nuts_bolts.h:
00025 #define square(x) ((x)*(x))
00026 #define sleep_mode(x) do {} while (0)
00027 // #define sei(x) 
00028 
00029 #define NUM_AXES 4
00030 
00031 #define X_AXIS 0
00032 #define Y_AXIS 1
00033 #define Z_AXIS 2
00034 #define E_AXIS 3
00035 
00036 #define clear_vector(a) memset(a, 0, sizeof(a))
00037 #define clear_vector_double(a) memset(a, 0.0, sizeof(a))
00038 #define max(a,b) (((a) > (b)) ? (a) : (b))
00039 #define min(a,b) (((a) < (b)) ? (a) : (b))
00040 // end
00041 
00042 /* From grbl/config.h */
00043 #define X_STEP_BIT    20           
00044 #define Y_STEP_BIT    25       
00045 #define Z_STEP_BIT    29       
00046 #define E_STEP_BIT    10       
00047 
00048 #define X_DIRECTION_BIT   23     
00049 #define Y_DIRECTION_BIT   26   
00050 #define Z_DIRECTION_BIT   0   
00051 #define E_DIRECTION_BIT   11   
00052 
00053 
00054 // This parameter sets the delay time before disabling the steppers after the final block of movement.
00055 // A short delay ensures the steppers come to a complete stop and the residual inertial force in the 
00056 // CNC axes don't cause the axes to drift off position. This is particularly important when manually 
00057 // entering g-code into grbl, i.e. locating part zero or simple manual machining. If the axes drift,
00058 // grbl has no way to know this has happened, since stepper motors are open-loop control. Depending
00059 // on the machine, this parameter may need to be larger or smaller than the default time.
00060 #define STEPPER_IDLE_LOCK_TIME 25 // (milliseconds)
00061 
00062 // The temporal resolution of the acceleration management subsystem. Higher number give smoother
00063 // acceleration but may impact performance.
00064 // NOTE: Increasing this parameter will help any resolution related issues, especially with machines 
00065 // requiring very high accelerations and/or very fast feedrates. In general, this will reduce the 
00066 // error between how the planner plans the motions and how the stepper program actually performs them.
00067 // However, at some point, the resolution can be high enough, where the errors related to numerical 
00068 // round-off can be great enough to cause problems and/or it's too fast for the Arduino. The correct
00069 // value for this parameter is machine dependent, so it's advised to set this only as high as needed.
00070 // Approximate successful values can range from 30L to 100L or more.
00071 #define ACCELERATION_TICKS_PER_SECOND 1000L
00072 
00073 // Minimum planner junction speed. Sets the default minimum speed the planner plans for at the end
00074 // of the buffer and all stops. This should not be much greater than zero and should only be changed
00075 // if unwanted behavior is observed on a user's machine when running at very slow speeds.
00076 #define MINIMUM_PLANNER_SPEED 0.0 // (mm/min)
00077 
00078 // Minimum stepper rate. Sets the absolute minimum stepper rate in the stepper program and never run
00079 // slower than this value, except when sleeping. This parameter overrides the minimum planner speed.
00080 // This is primarily used to guarantee that the end of a movement is always reached and not stop to
00081 // never reach its target. This parameter should always be greater than zero.
00082 #define MINIMUM_STEPS_PER_MINUTE 1200 // (steps/min) - Integer value only
00083 
00084 // Number of arc generation iterations by small angle approximation before exact arc
00085 // trajectory correction. Value must be 1-255. This parameter maybe decreased if there are issues
00086 // with the accuracy of the arc generations. In general, the default value is more than enough for
00087 // the intended CNC applications of grbl, and should be on the order or greater than the size of
00088 // the buffer to help with the computational efficiency of generating arcs.
00089 #define N_ARC_CORRECTION 25 
00090 
00091 // end
00092 
00093 #define LIMIT_MASK ((1<<X_LIMIT_BIT)|(1<<Y_LIMIT_BIT)|(1<<Z_LIMIT_BIT)) // All limit bits
00094 #define STEP_MASK ((1<<X_STEP_BIT)|(1<<Y_STEP_BIT)|(1<<Z_STEP_BIT)) // All step bits
00095 #define DIRECTION_MASK ((1<<X_DIRECTION_BIT)|(1<<Y_DIRECTION_BIT)|(1<<Z_DIRECTION_BIT)) // All direction bits
00096 #define STEPPING_MASK (STEP_MASK | DIRECTION_MASK) // All stepping-related bits (step/direction)
00097 
00098 // Initialize and start the stepper motor subsystem
00099 void st_init();
00100 
00101 // Block until all buffered steps are executed
00102 void st_synchronize();
00103 
00104 // Execute the homing cycle
00105 void st_go_home();
00106              
00107 // The stepper subsystem goes to sleep when it runs out of things to execute. Call this
00108 // to notify the subsystem that it is time to go to work.
00109 void st_wake_up();
00110 
00111 #endif