#4: PWM $ settings

Author: tbfleming

README.md

@@ -1,7 +1,8 @@
 ![GitHub Logo](https://github.com/gnea/gnea-Media/blob/master/Grbl%20Logo/Grbl%20Logo%20250px.png?raw=true)
 
 ***
-_Click the `Release` tab to download pre-compiled `.bin` files or just [click here](https://github.com/gnea/grbl-LPC/releases)_
+Old releases are in the `Release` tab. See [cprezzi's branch](https://github.com/cprezzi/grbl-LPC) for more recent releases.
+Note: cprezzi's branch disables current control and has defaults more suitable for other boards.
 ***
 This is GRBL 1.1 ported to the LPC1769. It can run on Smoothieboard.
 
@@ -10,23 +11,22 @@ Usage notes:
   If it doesn't, try installing VCOM_lib/usbser.inf.
 * This doesn't pass the sdcard to the host. Once installed you need to use a micro sdcard adaptor to replace or change it.
 * Only tested with lasers with PWM. Non-PWM spindle control not ported.
-* These are fixed PWM config values. To change these you'll have to change ```SPINDLE_PWM_*``` in config.h and rebuild.
-  * Pin 2.4
-  * 40 kHz
-  * PWM off value: 0%
-  * Mimimum PWM value: 0%
-  * Maximum PWM value: 100%
 * These are defaults for easy-to-change config values.
+  * WPos enabled for LaserWeb compatability ($10=0)
   * Laser mode: ON ($32)
   * Minimum S value: 0.0 ($31)
   * Maximum S value: 1.0 ($30)
 * Hard limits not yet ported
 * Control inputs not yet ported (e.g. Cycle Start and Safety Door switches)
 
 New configuration settings
+* $33 is PWM frequency in Hz
+* $34 is PWM off value in %
+* $35 is PWM min value in %
+* $36 is PWM max value in %
 * $140, $141, $142 are X, Y, Z current (amps)
-* Default to 0.0 A to avoid burning out your motors
-* Your motors will likely stall if you don't set these!
+  * Default to 0.0 A to avoid burning out your motors
+  * Your motors will likely stall if you don't set these!
 
 Build notes:
 * Include ```make``` and the ```arm-none-eabi-*``` tools in your path.

grbl/config.h

@@ -359,11 +359,6 @@
 //      pwm = scaled value. settings.rpm_min scales to SPINDLE_PWM_MIN_VALUE. settings.rpm_max
 //            scales to SPINDLE_PWM_MAX_VALUE.
 
-#define SPINDLE_PWM_PERIOD        (SystemCoreClock / 40000)         // SystemCoreClock / frequency
-#define SPINDLE_PWM_OFF_VALUE     (SPINDLE_PWM_PERIOD * 0.0)    // SPINDLE_PWM_PERIOD * fraction
-#define SPINDLE_PWM_MIN_VALUE     (SPINDLE_PWM_PERIOD * 0.0)    // SPINDLE_PWM_PERIOD * fraction
-#define SPINDLE_PWM_MAX_VALUE     (SPINDLE_PWM_PERIOD * 1.0)  // SPINDLE_PWM_PERIOD * fraction
-
 // Used by variable spindle output only. This forces the PWM output to a minimum duty cycle when enabled.
 // The PWM pin will still read 0V when the spindle is disabled. Most users will not need this option, but
 // it may be useful in certain scenarios. This minimum PWM settings coincides with the spindle rpm minimum
@@ -755,13 +750,17 @@
 #define DEFAULT_X_MAX_TRAVEL 200.0 // mm
 #define DEFAULT_Y_MAX_TRAVEL 200.0 // mm
 #define DEFAULT_Z_MAX_TRAVEL 200.0 // mm
+#define DEFAULT_SPINDLE_PWM_FREQ          5000        // Hz
+#define DEFAULT_SPINDLE_PWM_OFF_VALUE     0.0         // Percent
+#define DEFAULT_SPINDLE_PWM_MIN_VALUE     0.0         // Percent
+#define DEFAULT_SPINDLE_PWM_MAX_VALUE     100.0       // Percent
 #define DEFAULT_SPINDLE_RPM_MAX 1.0 // rpm
 #define DEFAULT_SPINDLE_RPM_MIN 0.0 // rpm
 #define DEFAULT_STEP_PULSE_MICROSECONDS 1
 #define DEFAULT_STEPPING_INVERT_MASK 0
 #define DEFAULT_DIRECTION_INVERT_MASK 0
 #define DEFAULT_STEPPER_IDLE_LOCK_TIME 25 // msec (0-254, 255 keeps steppers enabled)
-#define DEFAULT_STATUS_REPORT_MASK 1 // MPos enabled
+#define DEFAULT_STATUS_REPORT_MASK 0 // WPos enabled
 #define DEFAULT_JUNCTION_DEVIATION 0.01 // mm
 #define DEFAULT_ARC_TOLERANCE 0.002 // mm
 #define DEFAULT_REPORT_INCHES 0 // false

grbl/report.c

@@ -208,6 +208,10 @@ void report_grbl_settings() {
   #else
     report_util_uint8_setting(32,0);
   #endif
+  report_util_float_setting(33,settings.spindle_pwm_freq,N_DECIMAL_SETTINGVALUE);
+  report_util_float_setting(34,settings.spindle_pwm_off_value,N_DECIMAL_SETTINGVALUE);
+  report_util_float_setting(35,settings.spindle_pwm_min_value,N_DECIMAL_SETTINGVALUE);
+  report_util_float_setting(36,settings.spindle_pwm_max_value,N_DECIMAL_SETTINGVALUE);
   // Print axis settings
   uint8_t idx, set_idx;
   uint8_t val = AXIS_SETTINGS_START_VAL;

grbl/settings.c

@@ -86,6 +86,10 @@ void settings_restore(uint8_t restore_flag) {
     settings.junction_deviation = DEFAULT_JUNCTION_DEVIATION;
     settings.arc_tolerance = DEFAULT_ARC_TOLERANCE;
 
+    settings.spindle_pwm_freq = DEFAULT_SPINDLE_PWM_FREQ;
+    settings.spindle_pwm_off_value = DEFAULT_SPINDLE_PWM_OFF_VALUE;
+    settings.spindle_pwm_min_value = DEFAULT_SPINDLE_PWM_MIN_VALUE;
+    settings.spindle_pwm_max_value = DEFAULT_SPINDLE_PWM_MAX_VALUE;
     settings.rpm_max = DEFAULT_SPINDLE_RPM_MAX;
     settings.rpm_min = DEFAULT_SPINDLE_RPM_MIN;
 
@@ -317,6 +321,10 @@ uint8_t settings_store_global_setting(uint8_t parameter, float value) {
           return(STATUS_SETTING_DISABLED);
         #endif
         break;
+      case 33: settings.spindle_pwm_freq = value; spindle_init(); break; // Re-initialize spindle pwm calibration
+      case 34: settings.spindle_pwm_off_value = value; spindle_init(); break; // Re-initialize spindle pwm calibration
+      case 35: settings.spindle_pwm_min_value = value; spindle_init(); break; // Re-initialize spindle pwm calibration
+      case 36: settings.spindle_pwm_max_value = value; spindle_init(); break; // Re-initialize spindle pwm calibration
       default:
         return(STATUS_INVALID_STATEMENT);
     }

grbl/settings.h

@@ -92,6 +92,10 @@ typedef struct {
   float junction_deviation;
   float arc_tolerance;
 
+  float spindle_pwm_freq;      // Hz
+  float spindle_pwm_off_value; // Percent
+  float spindle_pwm_min_value; // Percent
+  float spindle_pwm_max_value; // Percent
   float rpm_max;
   float rpm_min;
 

grbl/spindle_control.c

@@ -25,13 +25,21 @@
 
 #ifdef VARIABLE_SPINDLE
   static float pwm_gradient; // Precalulated value to speed up rpm to PWM conversions.
+  float spindle_pwm_period;
+  float spindle_pwm_off_value;
+  float spindle_pwm_min_value;
+  float spindle_pwm_max_value;
 #endif
 
 
 void spindle_init()
 {
   #ifdef VARIABLE_SPINDLE
-    pwm_init(&SPINDLE_PWM_CHANNEL, SPINDLE_PWM_USE_PRIMARY_PIN, SPINDLE_PWM_USE_SECONDARY_PIN, SPINDLE_PWM_PERIOD, 0);
+    spindle_pwm_period = (SystemCoreClock / settings.spindle_pwm_freq);
+    spindle_pwm_off_value = (spindle_pwm_period * settings.spindle_pwm_off_value / 100);
+    spindle_pwm_min_value = (spindle_pwm_period * settings.spindle_pwm_min_value / 100);
+    spindle_pwm_max_value = (spindle_pwm_period * settings.spindle_pwm_max_value / 100);
+    pwm_init(&SPINDLE_PWM_CHANNEL, SPINDLE_PWM_USE_PRIMARY_PIN, SPINDLE_PWM_USE_SECONDARY_PIN, spindle_pwm_period, 0);
     pwm_enable(&SPINDLE_PWM_CHANNEL);
 
     /* not ported
@@ -44,7 +52,7 @@ void spindle_init()
     #endif
     */
 
-    pwm_gradient = (SPINDLE_PWM_MAX_VALUE-SPINDLE_PWM_MIN_VALUE)/(settings.rpm_max-settings.rpm_min);
+    pwm_gradient = (spindle_pwm_max_value-spindle_pwm_min_value)/(settings.rpm_max-settings.rpm_min);
 
   #else
     /* not ported
@@ -134,21 +142,21 @@ void spindle_stop()
     rpm *= (0.010*sys.spindle_speed_ovr); // Scale by spindle speed override value.
     if (rpm <= 0) {
       sys.spindle_speed = 0;
-      pwm_value = SPINDLE_PWM_OFF_VALUE;
+      pwm_value = spindle_pwm_off_value;
     }
     else if (rpm <= settings.rpm_min) {
       sys.spindle_speed = settings.rpm_min;
-      pwm_value = SPINDLE_PWM_MIN_VALUE;
+      pwm_value = spindle_pwm_min_value;
     }
     else if (rpm >= settings.rpm_max) {
       sys.spindle_speed = settings.rpm_max;
-      pwm_value = SPINDLE_PWM_MAX_VALUE - 1;
+      pwm_value = spindle_pwm_max_value - 1;
     }
     else {
       sys.spindle_speed = rpm;
-      pwm_value = floor((rpm - settings.rpm_min) * pwm_gradient) + SPINDLE_PWM_MIN_VALUE;
-      if(pwm_value >= SPINDLE_PWM_MAX_VALUE)
-        pwm_value = SPINDLE_PWM_MAX_VALUE - 1;
+      pwm_value = floor((rpm - settings.rpm_min) * pwm_gradient) + spindle_pwm_min_value;
+      if(pwm_value >= spindle_pwm_max_value)
+        pwm_value = spindle_pwm_max_value - 1;
     }
     return(pwm_value);
   }

grbl/spindle_control.h

@@ -40,6 +40,10 @@ uint8_t spindle_get_state();
 // Immediately sets spindle running state with direction and spindle rpm via PWM, if enabled.
 // Called by spindle_sync() after sync and parking motion/spindle stop override during restore.
 #ifdef VARIABLE_SPINDLE
+  extern float spindle_pwm_period;
+  extern float spindle_pwm_off_value;
+  extern float spindle_pwm_min_value;
+  extern float spindle_pwm_max_value;
 
   // Called by g-code parser when setting spindle state and requires a buffer sync.
   void spindle_sync(uint8_t state, float rpm);

grbl/stepper.c

@@ -385,7 +385,7 @@ extern "C" void TIMER1_IRQHandler()
       st_go_idle();
       #ifdef VARIABLE_SPINDLE
         // Ensure pwm is set properly upon completion of rate-controlled motion.
-        if (st.exec_block->is_pwm_rate_adjusted) { spindle_set_speed(SPINDLE_PWM_OFF_VALUE); }
+        if (st.exec_block->is_pwm_rate_adjusted) { spindle_set_speed(spindle_pwm_off_value); }
       #endif
       system_set_exec_state_flag(EXEC_CYCLE_STOP); // Flag main program for cycle end
       return; // Nothing to do but exit.
@@ -907,7 +907,7 @@ void st_prep_buffer()
           prep.current_spindle_pwm = spindle_compute_pwm_value(rpm);
         } else { 
           sys.spindle_speed = 0.0;
-          prep.current_spindle_pwm = SPINDLE_PWM_OFF_VALUE;
+          prep.current_spindle_pwm = spindle_pwm_off_value;
         }
         bit_false(sys.step_control,STEP_CONTROL_UPDATE_SPINDLE_PWM);
       }