refactored block buffer into separate module motion_plan pending the addition of the actual look ahead planner

Makefile

@@ -1,6 +1,6 @@
 #  Part of Grbl
 #
-#  Copyright (c) 2009 Simen Svale Skogsrud
+#  Copyright (c) 2009-2011 Simen Svale Skogsrud
 #
 #  Grbl is free software: you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -31,7 +31,7 @@ DEVICE     = atmega328p
 CLOCK      = 16000000
 PROGRAMMER = -c avrisp2 -P usb
 OBJECTS    = main.o motion_control.o gcode.o spindle_control.o wiring_serial.o serial_protocol.o stepper.o \
-             eeprom.o config.o
+             eeprom.o config.o motion_plan.o
 # FUSES      = -U hfuse:w:0xd9:m -U lfuse:w:0x24:m
 FUSES      = -U hfuse:w:0xd2:m -U lfuse:w:0xff:m
 

accelleration.h

@@ -1,51 +0,0 @@
-/*
-  accelleration.h - accelleration management support 
-  Part of Grbl
-
-  Copyright (c) 2009 Simen Svale Skogsrud
-
-  Grbl is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Grbl is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef accelleration_h
-#define accelleration_h 
-
-// Unless someone else defined AC_TICKS_PER_SECOND, we define a sensible default
-#ifndef AC_TICKS_PER_SECOND
-#define AC_TICKS_PER_SECOND 10
-#endif
-
-struct AccellerationProfile {
-  double initial_scaler;
-  double final_scaler;
-  double accelleration_delta;
-  double decelleration_delta;
-  uint32_t accellerate_ticks;
-  uint32_t plateau_ticks;    
-};
-
-struct AccellerationProfileSegment {
-  double v_entry[3];
-  double v_ideal[3];
-  double v_exit[3];
-  double distance;
-  double f_entry, f_exit;
-};
-
-struct AccellerationProfileBuilder {
-  AccellerationProfileSegment segment[3];
-  uint8_t current;
-};
-
-#endif 

config.c

@@ -2,7 +2,7 @@
   config.c - eeprom and compile time configuration handling 
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

config.h

@@ -2,7 +2,7 @@
   config.h - eeprom and compile time configuration handling 
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -27,8 +27,8 @@
 
 // Settings that can only be set at compile-time:
 
-// #define BAUD_RATE 9600
+#define BAUD_RATE 9600
-#define BAUD_RATE 115200
+//#define BAUD_RATE 115200
 
 #define STEPPERS_ENABLE_DDR     DDRD
 #define STEPPERS_ENABLE_PORT    PORTD

gcode.c

@@ -2,7 +2,7 @@
   gcode.c - rs274/ngc parser.
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

gcode.h

@@ -2,7 +2,7 @@
   gcode.c - rs274/ngc parser.
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

main.c

@@ -2,7 +2,7 @@
   main.c - An embedded CNC Controller with rs274/ngc (g-code) support
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -33,6 +33,7 @@
 int main(void)
 {
   beginSerial(BAUD_RATE);
+  printString("A");
   config_init();
   st_init(); // initialize the stepper subsystem
   mc_init(); // initialize motion control subsystem

motion_control.c

@@ -1,8 +1,8 @@
 /*
-  motion_control.c - cartesian robot controller.
+  motion_control.c - high level interface for issuing motion commands
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

motion_control.h

@@ -1,8 +1,8 @@
 /*
-  motion_control.h - cartesian robot controller.
+  motion_control.h - high level interface for issuing motion commands
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

motion_plan.c

@@ -0,0 +1,69 @@
+/*
+  motion_plan.c - buffers movement commands and manages the acceleration profile plan
+  Part of Grbl
+
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
+
+  Grbl is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Grbl is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <inttypes.h>
+#include <math.h>       
+
+#include "motion_plan.h"
+#include "nuts_bolts.h"
+#include "stepper.h"
+
+struct Block block_buffer[BLOCK_BUFFER_SIZE]; // A ring buffer for motion instructions
+volatile int block_buffer_head = 0;           // Index of the next block to be pushed
+volatile int block_buffer_tail = 0;           // Index of the block to process now
+
+inline uint32_t estimate_acceleration_distance(int32_t current_rate, int32_t target_rate, int32_t acceleration) {
+  return((target_rate*target_rate-current_rate*current_rate)/(2*acceleration));
+}
+
+inline uint32_t estimate_acceleration_ticks(int32_t start_rate, int32_t acceleration_per_tick, int32_t step_events) {
+  return(
+    round(
+      (sqrt(2*acceleration_per_tick*step_events+(start_rate*start_rate))-start_rate)/
+      acceleration_per_tick));
+}
+
+// Calculates trapezoid parameters so that the entry- and exit-speed is compensated by the provided factors.
+// In practice both factors must be in the range 0 ... 1.0
+void calculate_trapezoid_for_block(struct Block *block, double entry_factor, double exit_factor) {
+  block->initial_rate = max(round(block->nominal_rate*entry_factor),MINIMAL_STEP_RATE);
+  int32_t final_rate = max(round(block->nominal_rate*entry_factor),MINIMAL_STEP_RATE);
+  int32_t acceleration_per_second = block->rate_delta*ACCELERATION_TICKS_PER_SECOND;
+  int32_t acceleration_steps = 
+    estimate_acceleration_distance(block->initial_rate, block->nominal_rate, acceleration_per_second);
+  int32_t decelleration_steps = 
+    estimate_acceleration_distance(block->nominal_rate, final_rate, -acceleration_per_second);
+  // Check if the acceleration and decelleration periods overlap. In that case nominal_speed will
+  // never be reached but that's okay. Just truncate both periods proportionally so that they
+  // fit within the allotted step events.
+  int32_t plateau_steps = block->step_event_count-acceleration_steps-decelleration_steps;
+  if (plateau_steps < 0) {
+    int32_t half_overlap_region = fabs(plateau_steps)/2;
+    plateau_steps = 0;
+    acceleration_steps = max(acceleration_steps-half_overlap_region,0);
+    decelleration_steps = max(decelleration_steps-half_overlap_region,0);
+  }
+  block->accelerate_ticks = estimate_acceleration_ticks(block->initial_rate, block->rate_delta, acceleration_steps);
+  if (plateau_steps) {
+    block->plateau_ticks = round(1.0*plateau_steps/(block->nominal_rate*ACCELERATION_TICKS_PER_SECOND));
+  } else {
+    block->plateau_ticks = 0;
+  }
+}

motion_plan.h

@@ -0,0 +1,57 @@
+/*
+  motion_plan.h - buffers movement commands and manages the acceleration profile plan
+  Part of Grbl
+
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
+
+  Grbl is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Grbl is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef motion_plan_h
+#define motion_plan_h
+                 
+#include <inttypes.h>
+
+// Pick a suitable block-buffer size
+#ifdef __AVR_ATmega328P__
+#define BLOCK_BUFFER_SIZE 20   // Atmega 328 has one full kilobyte of extra RAM!
+#else
+#define BLOCK_BUFFER_SIZE 5
+#endif
+
+// This struct is used when buffering the setup for each linear movement
+// "nominal" values are as specified in the source g-code and may never
+// actually be reached if acceleration management is active.
+struct Block {
+  uint32_t steps_x, steps_y, steps_z; // Step count along each axis
+  uint8_t  direction_bits;            // The direction bit set for this block (refers to *_DIRECTION_BIT in config.h)
+  int32_t  step_event_count;          // The number of step events required to complete this block
+  uint32_t nominal_rate;              // The nominal step rate for this block in step_events/minute
+  // Values used for acceleration management
+  double  speed_x, speed_y, speed_z;   // Nominal mm/minute for each axis
+  uint32_t initial_rate;              // The jerk-adjusted step rate at start of block
+  int16_t rate_delta;                 // The steps/minute to add or subtract when changing speed (must be positive)
+  uint16_t accelerate_ticks;          // The number of acceleration-ticks to accelerate 
+  uint16_t plateau_ticks;             // The number of acceleration-ticks to maintain top speed
+};
+      
+extern struct Block block_buffer[BLOCK_BUFFER_SIZE]; // A ring buffer for motion instructions
+extern volatile int block_buffer_head;           // Index of the next block to be pushed
+extern volatile int block_buffer_tail;           // Index of the block to process now
+
+// Calculates trapezoid parameters so that the entry- and exit-speed is compensated by the provided factors.
+// In practice both factors must be in the range 0 ... 1.0
+void calculate_trapezoid_for_block(struct Block *block, double entry_factor, double exit_factor);
+
+#endif

notes/acceleration.c

@@ -2,7 +2,7 @@
   acceleration.c - support methods for acceleration-related calcul
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

nuts_bolts.h

@@ -2,7 +2,7 @@
   motion_control.h - cartesian robot controller.
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

script/console

@@ -1,4 +1,5 @@
 socat -d -d READLINE /dev/tty.usbserial-A700e0GO,clocal=1,nonblock=1,cread=1,cs8,ixon=1,ixoff=1
+socat -d -d READLINE /dev/tty.usbserial-A9007QcR,clocal=1,nonblock=1,cread=1,cs8,ixon=1,ixoff=1
 
 #socat -d -d READLINE /dev/tty.FireFly-A964-SPP-1,clocal=1,nonblock=1,cread=1,cs8,ixon=1,ixoff=1
 

serial_protocol.c

@@ -2,7 +2,7 @@
   serial_protocol.c - the serial protocol master control unit
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

serial_protocol.h

@@ -2,7 +2,7 @@
   serial_protocol.h - the serial protocol master control unit
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

spindle_control.c

@@ -2,7 +2,7 @@
   spindle_control.c - spindle control methods
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

spindle_control.h

@@ -2,7 +2,7 @@
   spindle_control.h - spindle control methods
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

stepper.c

@@ -1,8 +1,8 @@
 /*
-  stepper.c - stepper motor interface
+  stepper.c - stepper motor driver: executes motion plans using stepper motors
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -29,49 +29,20 @@
 #include <util/delay.h>
 #include "nuts_bolts.h"
 #include <avr/interrupt.h>
-
+#include "motion_plan.h"
 #include "wiring_serial.h"
 
-// Pick a suitable block-buffer size
-#ifdef __AVR_ATmega328P__
-#define BLOCK_BUFFER_SIZE 40   // Atmega 328 has one full kilobyte of extra RAM!
-#else
-#define BLOCK_BUFFER_SIZE 10
-#endif
-
-
 void set_step_events_per_minute(uint32_t steps_per_minute);
 
 #define ENABLE_STEPPER_DRIVER_INTERRUPT()  TIMSK1 |= (1<<OCIE1A)
 #define DISABLE_STEPPER_DRIVER_INTERRUPT() TIMSK1 &= ~(1<<OCIE1A)
 
-#define ACCELERATION_TICKS_PER_SECOND 10
-#define MINIMAL_STEP_RATE (ACCELERATION_TICKS_PER_SECOND*5)
 #define CYCLES_PER_ACCELERATION_TICK ((TICKS_PER_MICROSECOND*1000000)/ACCELERATION_TICKS_PER_SECOND)
 
-// This struct is used when buffering the setup for each linear movement
+struct Block *current_block;    // A convenience pointer to the block currently being traced
-// "nominal" values are as specified in the source g-code and may never
-// actually be reached if acceleration management is active.
-struct Block {
-  uint32_t steps_x, steps_y, steps_z; // Step count along each axis
-  uint8_t  direction_bits;            // The direction bit set for this block (refers to *_DIRECTION_BIT in config.h)
-  int32_t  step_event_count;          // The number of step events required to complete this block
-  uint32_t nominal_rate;              // The nominal step rate for this block in step_events/minute
-  // Values used for acceleration management
-  double  speed_x, speed_y, speed_z;   // Nominal mm/minute for each axis
-  uint32_t initial_rate;              // The jerk-adjusted step rate at start of block
-  int16_t rate_delta;                 // The steps/minute to add or subtract when changing speed (must be positive)
-  uint16_t accelerate_ticks;          // The number of acceleration-ticks to accelerate 
-  uint16_t plateau_ticks;             // The number of acceleration-ticks to maintain top speed
-};
-
-struct Block block_buffer[BLOCK_BUFFER_SIZE]; // A ring buffer for motion instructions
-volatile int block_buffer_head = 0;           // Index of the next block to be pushed
-volatile int block_buffer_tail = 0;           // Index of the block to process now
 
 // Variables used by The Stepper Driver Interrupt
 uint8_t out_bits;               // The next stepping-bits to be output
-struct Block *current_block;    // A pointer to the block currently being traced
 int32_t counter_x, 
         counter_y, 
         counter_z;              // counter variables for the bresenham line tracer
@@ -106,46 +77,9 @@ uint16_t trapezoid_stage_ticks;
 uint32_t trapezoid_rate;
 int16_t trapezoid_delta;
 
-inline uint32_t estimate_acceleration_distance(int32_t current_rate, int32_t target_rate, int32_t acceleration) {
-  return((target_rate*target_rate-current_rate*current_rate)/(2*acceleration));
-}
 
-inline uint32_t estimate_acceleration_ticks(int32_t start_rate, int32_t acceleration_per_tick, int32_t step_events) {
+// Initializes the trapezoid generator from the current block. Called whenever a new 
-  return(
+// block begins.
-    round(
-      (sqrt(2*acceleration_per_tick*step_events+(start_rate*start_rate))-start_rate)/
-      acceleration_per_tick));
-}
-
-// Calculates trapezoid parameters so that the entry- and exit-speed is compensated by the provided factors.
-// In practice both factors must be in the range 0 ... 1.0
-void calculate_trapezoid_for_block(struct Block *block, double entry_factor, double exit_factor) {
-  block->initial_rate = max(round(block->nominal_rate*entry_factor),MINIMAL_STEP_RATE);
-  int32_t final_rate = max(round(block->nominal_rate*entry_factor),MINIMAL_STEP_RATE);
-  int32_t acceleration_per_second = block->rate_delta*ACCELERATION_TICKS_PER_SECOND;
-  int32_t acceleration_steps = 
-    estimate_acceleration_distance(block->initial_rate, block->nominal_rate, acceleration_per_second);
-  int32_t decelleration_steps = 
-    estimate_acceleration_distance(block->nominal_rate, final_rate, -acceleration_per_second);
-  // Check if the acceleration and decelleration periods overlap. In that case nominal_speed will
-  // never be reached but that's okay. Just truncate both periods proportionally so that they
-  // fit within the allotted step events.
-  int32_t plateau_steps = block->step_event_count-acceleration_steps-decelleration_steps;
-  if (plateau_steps < 0) {
-    int32_t half_overlap_region = abs(plateau_steps)/2;
-    plateau_steps = 0;
-    acceleration_steps = max(acceleration_steps-half_overlap_region,0);
-    decelleration_steps = max(decelleration_steps-half_overlap_region,0);
-  }
-  block->accelerate_ticks = estimate_acceleration_ticks(block->initial_rate, block->rate_delta, acceleration_steps);
-  if (plateau_steps) {
-    block->plateau_ticks = round(1.0*plateau_steps/(block->nominal_rate*ACCELERATION_TICKS_PER_SECOND));
-  } else {
-    block->plateau_ticks = 0;
-  }
-}
-
-// Call this when a new block is started
 inline void reset_trapezoid_generator() {      
   trapezoid_stage = TRAPEZOID_STAGE_ACCELERATING;
   trapezoid_stage_ticks = current_block->accelerate_ticks;

stepper.h

@@ -1,8 +1,8 @@
 /*
-  stepper.h - stepper motor interface
+  stepper.h - stepper motor driver: executes motion plans using stepper motors
   Part of Grbl
 
-  Copyright (c) 2009 Simen Svale Skogsrud
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
 
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -24,6 +24,9 @@
 #include <avr/io.h>
 #include <avr/sleep.h>
 
+#define ACCELERATION_TICKS_PER_SECOND 10
+#define MINIMAL_STEP_RATE (ACCELERATION_TICKS_PER_SECOND*5)
+
 // Initialize and start the stepper motor subsystem
 void st_init();
 

todo.txt

@@ -1,5 +1,8 @@
-* Complete support for using and setting separate seek-rate for G0-commnads
+Todo
+* Refactor stepper.c extracting motion blocks so that they can be processed by other code
+* non blocking dwells
+* Path Control Modes
 * Implement limit switch support in stepper.c (use port-triggered interrupts?)
 * Implement homing cycle in stepper.c
-* Path Control Modes
 * Spindle speed support
+