src/libs/StepTicker.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
   8
   9
  10 using namespace std;
  11 #include <vector>
  12 #include "libs/nuts_bolts.h"
  13 #include "libs/Module.h"
  14 #include "libs/Kernel.h"
  15 #include "StepTicker.h"
  16 #include "system_LPC17xx.h" // mbed.h lib
  17
  18 #include <mri.h>
  19
  20 // StepTicker handles the base frequency ticking for the Stepper Motors / Actuators
  21 // It has a list of those, and calls their tick() functions at regular intervals
  22 // They then do Bresenham stuff themselves
  23
  24 StepTicker* global_step_ticker;
  25
  26 StepTicker::StepTicker(){
  27     global_step_ticker = this;
  28
  29     // Configure the timer
  30     LPC_TIM0->MR0 = 10000000;       // Initial dummy value for Match Register
  31     LPC_TIM0->MCR = 3;              // Match on MR0, reset on MR0, match on MR1
  32     LPC_TIM0->TCR = 0;              // Disable interrupt
  33
  34     LPC_SC->PCONP |= (1 << 2);      // Power Ticker ON
  35     LPC_TIM1->MR0 = 1000000;
  36     LPC_TIM1->MCR = 1;
  37     LPC_TIM1->TCR = 1;              // Enable interrupt
  38
  39     // Default start values
  40     this->moves_finished = false;
  41     this->reset_step_pins = false;
  42     this->debug = 0;
  43     this->has_axes = 0;
  44     this->set_frequency(0.001);
  45     this->set_reset_delay(100);
  46     this->last_duration = 0;
  47     for (int i = 0; i < 12; i++){
  48         this->active_motors[i] = NULL;
  49     }
  50     this->active_motor_bm = 0;
  51
  52     NVIC_EnableIRQ(TIMER0_IRQn);     // Enable interrupt handler
  53     NVIC_EnableIRQ(TIMER1_IRQn);     // Enable interrupt handler
  54 }
  55
  56 // Set the base stepping frequency
  57 void StepTicker::set_frequency( double frequency ){
  58     this->frequency = frequency;
  59     this->period = int(floor((SystemCoreClock/4)/frequency));  // SystemCoreClock/4 = Timer increments in a second
  60     LPC_TIM0->MR0 = this->period;
  61     if( LPC_TIM0->TC > LPC_TIM0->MR0 ){
  62         LPC_TIM0->TCR = 3;  // Reset
  63         LPC_TIM0->TCR = 1;  // Reset
  64     }
  65 }
  66
  67 // Set the reset delay
  68 void StepTicker::set_reset_delay( double seconds ){
  69     this->delay = int(floor(double(SystemCoreClock/4)*( seconds )));  // SystemCoreClock/4 = Timer increments in a second
  70     LPC_TIM1->MR0 = this->delay;
  71 }
  72
  73 // Add a stepper motor object to our list of steppers we must take care of
  74 StepperMotor* StepTicker::add_stepper_motor(StepperMotor* stepper_motor){
  75     this->stepper_motors.push_back(stepper_motor);
  76     stepper_motor->step_ticker = this;
  77     this->has_axes = true;
  78     return stepper_motor;
  79 }
  80
  81 // Call tick() on each active motor
  82 inline void StepTicker::tick(){
  83     _isr_context = true;
  84     int i;
  85     uint32_t bm = 1;
  86     // We iterate over each active motor
  87     for (i = 0; i < 12; i++, bm <<= 1){
  88         if (this->active_motor_bm & bm){
  89             this->active_motors[i]->tick();
  90         }
  91     }
  92     _isr_context = false;
  93 }
  94
  95 // Call signal_mode_finished() on each active motor that asked to be signaled. We do this instead of inside of tick() so that
  96 // all tick()s are called before we do the move finishing
  97 void StepTicker::signal_moves_finished(){
  98     _isr_context = true;
  99
 100     uint16_t bitmask = 1;
 101     for ( uint8_t motor = 0; motor < 12; motor++, bitmask <<= 1){
 102         if (this->active_motor_bm & bitmask){
 103             if(this->active_motors[motor]->is_move_finished){
 104                 this->active_motors[motor]->signal_move_finished();
 105                 if(this->active_motors[motor]->moving == false){
 106                     if (motor > 0){
 107                         motor--;
 108                         bitmask >>= 1;
 109                     }
 110                 }
 111             }
 112         }
 113     }
 114     this->moves_finished = false;
 115
 116     _isr_context = false;
 117 }
 118
 119 // Reset step pins on all active motors
 120 inline void StepTicker::reset_tick(){
 121     _isr_context = true;
 122
 123     int i;
 124     uint32_t bm;
 125     for (i = 0, bm = 1; i < 12; i++, bm <<= 1)
 126     {
 127         if (this->active_motor_bm & bm)
 128             this->active_motors[i]->step_pin->set(0);
 129     }
 130
 131     _isr_context = false;
 132 }
 133
 134 extern "C" void TIMER1_IRQHandler (void){
 135     LPC_TIM1->IR |= 1 << 0;
 136     global_step_ticker->reset_tick();
 137 }
 138
 139 // The actual interrupt handler where we do all the work
 140 extern "C" void TIMER0_IRQHandler (void){
 141
 142     // Reset interrupt register
 143     LPC_TIM0->IR |= 1 << 0;
 144
 145     // Step pins
 146     uint16_t bitmask = 1;
 147     for (uint8_t motor = 0; motor < 12; motor++, bitmask <<= 1){
 148         if (global_step_ticker->active_motor_bm & bitmask){
 149             global_step_ticker->active_motors[motor]->tick();
 150         }
 151     }
 152
 153     // We may have set a pin on in this tick, now we start the timer to set it off
 154     if( global_step_ticker->reset_step_pins ){
 155         LPC_TIM1->TCR = 3;
 156         LPC_TIM1->TCR = 1;
 157         global_step_ticker->reset_step_pins = false;
 158     }else{
 159         // Nothing happened, nothing after this really matters
 160         // TODO : This could be a problem when we use Actuators instead of StepperMotors, because this flag is specific to step generation
 161         LPC_TIM0->MR0 = global_step_ticker->period;
 162         return;
 163     }
 164
 165     // If a move finished in this tick, we have to tell the actuator to act accordingly
 166     if( global_step_ticker->moves_finished ){
 167
 168         // Do not get out of here before everything is nice and tidy
 169         LPC_TIM0->MR0 = 20000000;
 170
 171         global_step_ticker->signal_moves_finished();
 172
 173         // If we went over the duration an interrupt is supposed to last, we have a problem
 174         // That can happen tipically when we change blocks, where more than usual computation is done
 175         // This can be OK, if we take notice of it, which we do now
 176         if( LPC_TIM0->TC > global_step_ticker->period ){ // TODO: remove the size condition
 177
 178             uint32_t start_tc = LPC_TIM0->TC;
 179
 180             // How many ticks we want to skip ( this does not include the current tick, but we add the time we spent doing this computation last time )
 181             uint32_t ticks_to_skip = (  ( LPC_TIM0->TC + global_step_ticker->last_duration ) / global_step_ticker->period );
 182
 183             // Next step is now to reduce this to how many steps we can *actually* skip
 184             uint32_t ticks_we_actually_can_skip = ticks_to_skip;
 185
 186             int i;
 187             uint32_t bm;
 188             for (i = 0, bm = 1; i < 12; i++, bm <<= 1)
 189             {
 190                 if (global_step_ticker->active_motor_bm & bm)
 191                     ticks_we_actually_can_skip =
 192                         min(ticks_we_actually_can_skip,
 193                             (uint32_t)((uint64_t)( (uint64_t)global_step_ticker->active_motors[i]->fx_ticks_per_step - (uint64_t)global_step_ticker->active_motors[i]->fx_counter ) >> 32)
 194                             );
 195             }
 196
 197             // Adding to MR0 for this time is not enough, we must also increment the counters ourself artificially
 198             for (i = 0, bm = 1; i < 12; i++, bm <<= 1)
 199             {
 200                 if (global_step_ticker->active_motor_bm & bm)
 201                     global_step_ticker->active_motors[i]->fx_counter += (uint64_t)((uint64_t)(ticks_we_actually_can_skip)<<32);
 202             }
 203
 204             // When must we have our next MR0 ? ( +1 is here to account that we are actually doing a legit MR0 match here too, not only overtime )
 205             LPC_TIM0->MR0 = ( ticks_to_skip + 1 ) * global_step_ticker->period;
 206
 207             // This is so that we know how long this computation takes, and we can take it into account next time
 208             int difference = (int)(LPC_TIM0->TC) - (int)(start_tc);
 209             if( difference > 0 ){ global_step_ticker->last_duration = (uint32_t)difference; }
 210
 211         }else{
 212             LPC_TIM0->MR0 = global_step_ticker->period;
 213         }
 214
 215         while( LPC_TIM0->TC > LPC_TIM0->MR0 ){
 216             LPC_TIM0->MR0 += global_step_ticker->period;
 217         }
 218
 219     }
 220
 221 }
 222
 223
 224 // We make a list of steppers that want to be called so that we don't call them for nothing
 225 void StepTicker::add_motor_to_active_list(StepperMotor* motor)
 226 {
 227     uint32_t bm;
 228     int i;
 229     for (i = 0, bm = 1; i < 12; i++, bm <<= 1)
 230     {
 231         if (this->active_motors[i] == motor)
 232         {
 233             this->active_motor_bm |= bm;
 234             if( this->active_motor_bm != 0 ){
 235                 LPC_TIM0->TCR = 1;               // Enable interrupt
 236             }
 237             return;
 238         }
 239         if (this->active_motors[i] == NULL)
 240         {
 241             this->active_motors[i] = motor;
 242             this->active_motor_bm |= bm;
 243             if( this->active_motor_bm != 0 ){
 244                 LPC_TIM0->TCR = 1;               // Enable interrupt
 245             }
 246             return;
 247         }
 248     }
 249     return;
 250 }
 251
 252 // Remove a stepper from the list of active motors
 253 void StepTicker::remove_motor_from_active_list(StepperMotor* motor)
 254 {
 255     uint32_t bm; int i;
 256     for (i = 0, bm = 1; i < 12; i++, bm <<= 1)
 257     {
 258         if (this->active_motors[i] == motor)
 259         {
 260             this->active_motor_bm &= ~bm;
 261             // If we have no motor to work on, disable the whole interrupt
 262             if( this->active_motor_bm == 0 ){
 263                 LPC_TIM0->TCR = 0;               // Disable interrupt
 264             }
 265             return;
 266         }
 267     }
 268 }