Commit f4301419 authored by bdring's avatar bdring
Browse files

Added limit switch debouncing. 

- limit Switch debouncing can be enabled in config.h
- #127
parent 228e7983

Grbl_Esp32/config.h

+5 −8
Original line number Diff line number Diff line
@@ -561,14 +561,11 @@ Some features should not be changed. See notes below. 
// #define RX_BUFFER_SIZE 128 // (1-254) Uncomment to override defaults in serial.h

// #define TX_BUFFER_SIZE 100 // (1-254)



// A simple software debouncing feature for hard limit switches. When enabled, the interrupt 

// monitoring the hard limit switch pins will enable the Arduino's watchdog timer to re-check 

// the limit pin state after a delay of about 32msec. This can help with CNC machines with 

// problematic false triggering of their hard limit switches, but it WILL NOT fix issues with 

// electrical interference on the signal cables from external sources. It's recommended to first

// use shielded signal cables with their shielding connected to ground (old USB/computer cables 

// work well and are cheap to find) and wire in a low-pass circuit into each limit pin.

// A simple software debouncing feature for hard limit switches. When enabled, the limit 

// switch interrupt unblock a waiting task which will recheck the limit switch pins after 

// a short delay. Default disabled

//#define ENABLE_SOFTWARE_DEBOUNCE // Default disabled. Uncomment to enable.

#define DEBOUNCE_PERIOD 32 // in milliseconds default 32 microseconds



// Configures the position after a probing cycle during Grbl's check mode. Disabled sets

// the position to the probe target, when enabled sets the position to the start position.

Grbl_Esp32/grbl_limits.cpp

+74 −56
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ 


#include "grbl.h"





xQueueHandle limit_sw_queue;  // used by limit switch debouncing



// Homing axis search distance multiplier. Computed by this value times the cycle travel.

#ifndef HOMING_AXIS_SEARCH_SCALAR
@@ -47,6 +47,12 @@ void IRAM_ATTR isr_limit_switches() 


	if (  ( sys.state != STATE_ALARM) & (bit_isfalse(sys.state, STATE_HOMING)) ) {

		if (!(sys_rt_exec_alarm)) {

			

			#ifdef ENABLE_SOFTWARE_DEBOUNCE

				// we will start a task that will recheck the switches after a small delay

				int evt;

				xQueueSendFromISR(limit_sw_queue, &evt, NULL);	

			#else

				#ifdef HARD_LIMIT_FORCE_STATE_CHECK

				  // Check limit pin state.

				  if (limits_get_state()) {
@@ -57,6 +63,7 @@ void IRAM_ATTR isr_limit_switches() 
				  mc_reset(); // Initiate system kill.

				  system_set_exec_alarm(EXEC_ALARM_HARD_LIMIT); // Indicate hard limit critical event

				#endif				

			#endif

		}						

    }

}
@@ -300,15 +307,17 @@ void limits_init() 
    limits_disable();

  }

  

	// setup task used for debouncing

	limit_sw_queue = xQueueCreate(10, sizeof( int ));

	

	xTaskCreate(limitCheckTask, 

				"limitCheckTask", 

				2048, 

				NULL, 

				5, // priority 

				NULL);

								

								

// TODO Debounce

/*

  #ifdef ENABLE_SOFTWARE_DEBOUNCE

    MCUSR &= ~(1<<WDRF);

    WDTCSR |= (1<<WDCE) | (1<<WDE);

    WDTCSR = (1<<WDP0); // Set time-out at ~32msec.

  #endif

 */ 

}
@@ -332,9 +341,11 @@ uint8_t limits_get_state() 
	#ifdef X_LIMIT_PIN

		pin += digitalRead(X_LIMIT_PIN);

	#endif

	

	#ifdef Y_LIMIT_PIN

		pin += (digitalRead(Y_LIMIT_PIN) << Y_AXIS);

	#endif

	

	#ifdef Z_LIMIT_PIN

		pin += (digitalRead(Z_LIMIT_PIN) << Z_AXIS);

	#endif
@@ -343,8 +354,7 @@ uint8_t limits_get_state() 
		pin ^= INVERT_LIMIT_PIN_MASK;

	#endif	

  

  if (bit_istrue(settings.flags,BITFLAG_INVERT_LIMIT_PINS)) 

	{ 

	if (bit_istrue(settings.flags,BITFLAG_INVERT_LIMIT_PINS)) { 

		pin ^= LIMIT_MASK;

	}
@@ -356,16 +366,8 @@ uint8_t limits_get_state() 
	}

	

	return(limit_state);	

  

	

}















// Performs a soft limit check. Called from mc_line() only. Assumes the machine has been homed,

// the workspace volume is in all negative space, and the system is in normal operation.

// NOTE: Used by jogging to limit travel within soft-limit volume.
@@ -383,6 +385,7 @@ void limits_soft_check(float *target) 
			if (sys.abort) { return; }

		} while ( sys.state != STATE_IDLE );

    }

	

    mc_reset(); // Issue system reset and ensure spindle and coolant are shutdown.

    system_set_exec_alarm(EXEC_ALARM_SOFT_LIMIT); // Indicate soft limit critical event

    protocol_execute_realtime(); // Execute to enter critical event loop and system abort
@@ -390,6 +393,21 @@ void limits_soft_check(float *target) 
  }

}



// this is the task

void limitCheckTask(void *pvParameters)

{	

	while(true) {

		int evt;

		xQueueReceive(limit_sw_queue, &evt, portMAX_DELAY); // block until receive queue

		vTaskDelay( DEBOUNCE_PERIOD / portTICK_PERIOD_MS ); // delay a while

		

		if (limits_get_state()) {

			mc_reset(); // Initiate system kill.

			system_set_exec_alarm(EXEC_ALARM_HARD_LIMIT); // Indicate hard limit critical event

		}		

	}

}



// return true if the axis is defined as a squared axis

// Squaring: is used on gantry type axes that have two motors

// Each motor with touch off its own switch to square the axis

Grbl_Esp32/grbl_limits.h

+3 −2
Original line number Diff line number Diff line
@@ -32,8 +32,6 @@ 
#define SQUARING_MODE_A			1  // A motor runs

#define SQUARING_MODE_B			2  // B motor runs







// Initialize the limits module

void limits_init();
@@ -53,4 +51,7 @@ void isr_limit_switches(); 


bool axis_is_squared(uint8_t axis_mask);



// A task that runs after a limit switch interrupt.

void limitCheckTask(void *pvParameters); 



#endif
 
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