src/libs/StepperMotor.cpp

   1 /*
   2       This file is part of Smoothie (http://smoothieware.org/). The motion control part is heavily based on Grbl (https://github.com/simen/grbl).
   3       Smoothie 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.
   4       Smoothie 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.
   5       You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>.
   6 */
   7 #include "StepperMotor.h"
   8
   9 #include "Kernel.h"
  10 #include "MRI_Hooks.h"
  11 #include "StepTicker.h"
  12
  13 #include <math.h>
  14
  15 // in steps/sec the default minimum speed (was 20steps/sec hardcoded)
  16 float StepperMotor::default_minimum_actuator_rate= 20.0F;
  17
  18 // A StepperMotor represents an actual stepper motor. It is used to generate steps that move the actual motor at a given speed
  19 // TODO : Abstract this into Actuator
  20
  21 StepperMotor::StepperMotor()
  22 {
  23     init();
  24 }
  25
  26 StepperMotor::StepperMotor(Pin &step, Pin &dir, Pin &en) : step_pin(step), dir_pin(dir), en_pin(en)
  27 {
  28     init();
  29     enable(false);
  30     set_high_on_debug(en.port_number, en.pin);
  31 }
  32
  33 StepperMotor::~StepperMotor()
  34 {
  35     delete step_signal_hook;
  36 }
  37
  38 void StepperMotor::init()
  39 {
  40     this->moving = false;
  41     this->paused = false;
  42     this->fx_counter = 0;
  43     this->stepped = 0;
  44     this->fx_ticks_per_step = 0;
  45     this->steps_to_move = 0;
  46     this->is_move_finished = false;
  47     this->signal_step = false;
  48     this->step_signal_hook = new Hook();
  49
  50     steps_per_mm         = 1.0F;
  51     max_rate             = 50.0F;
  52     minimum_step_rate    = default_minimum_actuator_rate;
  53
  54     last_milestone_steps = 0;
  55     last_milestone_mm    = 0.0F;
  56     current_position_steps= 0;
  57 }
  58
  59
  60 // This is called ( see the .h file, we had to put a part of things there for obscure inline reasons ) when a step has to be generated
  61 // we also here check if the move is finished etc ...
  62 void StepperMotor::step()
  63 {
  64     // output to pins 37t
  65     this->step_pin.set( 1 );
  66     THEKERNEL->step_ticker->reset_step_pins = true;
  67
  68     // move counter back 11t
  69     if(this->fx_counter > this->fx_ticks_per_step) {
  70         this->fx_counter -= this->fx_ticks_per_step;
  71     }else{
  72         this->fx_counter= 0; // can't make it less than 0 as it is a uint, unless we get interrupted I don't think this case is possible
  73     }
  74
  75     // we have moved a step 9t
  76     this->stepped++;
  77
  78     // Do we need to signal this step
  79     if( this->stepped == this->signal_step_number && this->signal_step ) {
  80         this->step_signal_hook->call();
  81     }
  82
  83     // keep track of actuators actual position in steps
  84     this->current_position_steps += (this->direction ? -1 : 1);
  85
  86     // Is this move finished ?
  87     if( this->stepped == this->steps_to_move ) {
  88         // Mark it as finished, then StepTicker will call signal_mode_finished()
  89         // This is so we don't call that before all the steps have been generated for this tick()
  90         this->is_move_finished = true;
  91         THEKERNEL->step_ticker->a_move_finished = true;
  92     }
  93 }
  94
  95
  96 // If the move is finished, the StepTicker will call this ( because we asked it to in tick() )
  97 void StepperMotor::signal_move_finished()
  98 {
  99     // work is done ! 8t
 100     this->moving = false;
 101     this->steps_to_move = 0;
 102     this->minimum_step_rate = default_minimum_actuator_rate;
 103
 104     // signal it to whatever cares 41t 411t
 105     this->end_hook->call();
 106
 107     // We only need to do this if we were not instructed to move
 108     if( this->moving == false ) {
 109         this->update_exit_tick();
 110     }
 111
 112     this->is_move_finished = false;
 113 }
 114
 115 // This is just a way not to check for ( !this->moving || this->paused || this->fx_ticks_per_step == 0 ) at every tick()
 116 inline void StepperMotor::update_exit_tick()
 117 {
 118     if( !this->moving || this->paused || this->steps_to_move == 0 ) {
 119         // We must exit tick() after setting the pins, no bresenham is done
 120         THEKERNEL->step_ticker->remove_motor_from_active_list(this);
 121     } else {
 122         // We must do the bresenham in tick()
 123         // We have to do this or there could be a bug where the removal still happens when it doesn't need to
 124         THEKERNEL->step_ticker->add_motor_to_active_list(this);
 125     }
 126 }
 127
 128 // Instruct the StepperMotor to move a certain number of steps
 129 void StepperMotor::move( bool direction, unsigned int steps, float initial_speed)
 130 {
 131     // We do not set the direction directly, we will set the pin just before the step pin on the next tick
 132     this->dir_pin.set(direction);
 133     this->direction = direction;
 134
 135     // How many steps we have to move until the move is done
 136     this->steps_to_move = steps;
 137
 138     // Zero our tool counters
 139     this->fx_counter = 0;      // Bresenheim counter
 140     this->stepped = 0;
 141
 142     // Do not signal steps until we get instructed to
 143     this->signal_step = false;
 144
 145     // Starting now we are moving
 146     if( steps > 0 ) {
 147         if(initial_speed >= 0.0F) set_speed(initial_speed);
 148         this->moving = true;
 149     } else {
 150         this->moving = false;
 151     }
 152     this->update_exit_tick();
 153 }
 154
 155 // this is called to set the step rate based on this blocks rate, we use this instead of set_speed for coordinated moves
 156 // so that we can floor to a minimum speed which is proportional for all axis. the minimum step rate is set at the start
 157 // of each block based on the slowest axis of all coordinated axis.
 158 // the rate passed in is the requested rate, it is scaled for this motor based on steps_to_move and block_steps_event_count
 159 void StepperMotor::set_step_rate(float requested_rate, uint32_t block_steps_event_count)
 160 {
 161     float rate= requested_rate * ((float)steps_to_move / (float)block_steps_event_count);
 162     if(rate < minimum_step_rate) {
 163         rate= minimum_step_rate;
 164     }
 165     set_speed(rate);
 166 }
 167
 168 // Set the speed at which this stepper moves in steps/sec, should be called set_step_rate()
 169 // we need to make sure that we have a minimum speed here and that it fits the 64bit fixed point fx counters
 170 // Note nothing will really ever go as slow as the minimum speed here, it is just forced to avoid bad errors
 171 // fx_ticks_per_step is what actually sets the step rate, it is fixed point 32.32
 172 void StepperMotor::set_speed( float speed )
 173 {
 174     if(speed <= 0.0F) { // we can't actually do 0 but we can get close, need to avoid divide by zero later on
 175         this->fx_ticks_per_step= 0xFFFFF00000000000ULL; // that is 4,294,963,200 10us ticks which is ~11.9 hours for 1 step
 176         this->steps_per_second = THEKERNEL->step_ticker->frequency / (this->fx_ticks_per_step>>fx_shift);
 177         return;
 178     }
 179
 180     // How many steps we must output per second
 181     this->steps_per_second = speed;
 182
 183     // How many ticks ( base steps ) between each actual step at this speed, in fixed point 64
 184     // we need to use double here to match the 64bit resolution of the ticker
 185     double ticks_per_step = (double)THEKERNEL->step_ticker->frequency / speed;
 186     if(ticks_per_step > 0xFFFFF000UL) { // maximum we can really do and allow a few overflow steps
 187         ticks_per_step= 0xFFFFF000UL;
 188         this->steps_per_second = THEKERNEL->step_ticker->frequency / ticks_per_step;
 189     }
 190     double double_fx_ticks_per_step = fx_increment * ticks_per_step;
 191
 192     // set the new speed
 193     this->fx_ticks_per_step = floor(double_fx_ticks_per_step);
 194 }
 195
 196 // Pause this stepper motor
 197 void StepperMotor::pause()
 198 {
 199     this->paused = true;
 200     this->update_exit_tick();
 201 }
 202
 203 // Unpause this stepper motor
 204 void StepperMotor::unpause()
 205 {
 206     this->paused = false;
 207     this->update_exit_tick();
 208 }
 209
 210
 211 void StepperMotor::change_steps_per_mm(float new_steps)
 212 {
 213     steps_per_mm = new_steps;
 214     last_milestone_steps = lround(last_milestone_mm * steps_per_mm);
 215     current_position_steps = last_milestone_steps;
 216 }
 217
 218 void StepperMotor::change_last_milestone(float new_milestone)
 219 {
 220     last_milestone_mm = new_milestone;
 221     last_milestone_steps = lround(last_milestone_mm * steps_per_mm);
 222     current_position_steps = last_milestone_steps;
 223 }
 224
 225 int  StepperMotor::steps_to_target(float target)
 226 {
 227     int target_steps = lround(target * steps_per_mm);
 228     return target_steps - last_milestone_steps;
 229 }