New alarm method. Re(re)organized status messages.

- Installed a new 'alarm' method to centralize motion kills across
alarm or reset events. Right now, this is controlled by system abort
and hard limits. But, in the future, a g-code parser error may call
this too as a safety feature.

- Re(re)organized status messages to just print all errors, regardless
from where it was called. This centralizes them into one place.

- Misc messages method installed for any user feedback that is not a
confirmation or error. Mainly so that there is a place to perform
warnings and such.

- New stuff installed and still made the flash size smaller by saving
flash space from clearing out repeated '\r\n' pgmstrings.

- Fixed a bug where hard limits message would print everytime a system
abort was sent.

limits.c

@@ -56,16 +56,14 @@ ISR(LIMIT_INT_vect)
   if (bit_isfalse(sys.execute,EXEC_ALARM)) { 
     // Kill all processes upon hard limit event.
     if ((LIMIT_PIN & LIMIT_MASK) ^ LIMIT_MASK) {
-      st_go_idle(); // Immediately stop stepper motion
+      mc_alarm(); // Initiate system kill.
-      spindle_stop(); // Stop spindle
+      protocol_status_message(STATUS_HARD_LIMIT); // Print ok in interrupt since system killed.
-      sys.auto_start = false; // Disable auto cycle start.
-      sys.execute |= EXEC_ALARM;
-      // TODO: When Grbl system status is installed, update here to indicate loss of position.
     } 
     // else {
     //   TODO: When leaving a switch, this interrupt can be activated upon detecting a pin
     //   change to high. If so, need to start a countdown timer to check the pin again after
-    //   a debounce period to not falsely re-engage the alarm.
+    //   a debounce period to not falsely re-engage the alarm. Not essential, but *could* be
+    //   a minor annoyance.
   }
 }
 

motion_control.c

@@ -25,6 +25,8 @@
 #include "config.h"
 #include "gcode.h"
 #include "motion_control.h"
+#include "spindle_control.h"
+#include "coolant_control.h"
 #include <util/delay.h>
 #include <math.h>
 #include <stdlib.h>
@@ -223,3 +225,24 @@ void mc_go_home()
     PCICR |= (1 << LIMIT_INT);  // Re-enable hard limits.
   }
 }
+
+
+// Method to immediately kill all motion and set system alarm. Used by system abort, hard limits,
+// and upon g-code parser error (when installed).
+void mc_alarm()
+{
+  // Only this function can set the system alarm. This is done to prevent multiple kill calls 
+  // by different processes.
+  if (bit_isfalse(sys.execute, EXEC_ALARM)) {
+    sys.execute |= EXEC_ALARM; // Set alarm to allow subsystem disable for certain settings.
+    sys.auto_start = false; // Disable auto cycle start.
+          
+    // TODO: When Grbl system status is installed, set position lost state if the cycle is active.
+    // if (sys.cycle_start) { POSITION LOST } 
+        
+    // Immediately force stepper, spindle, and coolant to stop.
+    st_go_idle();  
+    spindle_stop();
+    coolant_stop();
+  }
+}

motion_control.h

@@ -43,4 +43,7 @@ void mc_dwell(float seconds);
 // Send the tool home (not implemented)
 void mc_go_home();
 
+// Kills all motion and sets system alarm
+void mc_alarm();
+
 #endif

protocol.c

@@ -36,20 +36,16 @@ static char line[LINE_BUFFER_SIZE]; // Line to be executed. Zero-terminated.
 static uint8_t char_counter; // Last character counter in line variable.
 static uint8_t iscomment; // Comment/block delete flag for processor to ignore comment characters.
 
-// Prints all status messages, an 'ok' or 'error', after Grbl has processed a line of incoming
+// Method to handle status messages, from an 'ok' to report any 'error' that has occurred.
-// serial data, whether this was a g-code block or grbl setting command.
+// Errors can originate from the g-code parser, settings module, or a critical error, such
-void protocol_status_message(int8_t status_code) 
+// as a triggered hard limit.
+void protocol_status_message(uint8_t status_code) 
 {
   // TODO: Compile time option to only return numeric codes for GUIs.
   if (status_code == 0) { // STATUS_OK
     printPgmString(PSTR("ok\r\n"));
   } else {
     printPgmString(PSTR("error: "));
-    // All critical error codes are greater than zero. These are defined to be any error
-    // that may cause damage by crashing or improper g-code inputs and that are susceptible
-    // to Grbl's alarm mode which will stop all processes, if the user enables this option.
-    if (status_code > 0) { 
-      // TODO: Install option to enter alarm mode upon any critical error.
     switch(status_code) {          
       case STATUS_BAD_NUMBER_FORMAT:
       printPgmString(PSTR("Bad number format")); break;
@@ -62,42 +58,32 @@ void protocol_status_message(int8_t status_code)
       case STATUS_MODAL_GROUP_VIOLATION:
       printPgmString(PSTR("Modal group violation")); break;
       case STATUS_INVALID_STATEMENT:
-        printPgmString(PSTR("Invalid gcode statement")); break;
+      printPgmString(PSTR("Invalid statement")); break;
+      case STATUS_HARD_LIMIT:
+      printPgmString(PSTR("<ALARM> Limit triggered")); break;
       case STATUS_SETTING_DISABLED:
       printPgmString(PSTR("Grbl setting disabled")); break;
-        case STATUS_HARD_LIMIT:
-        printPgmString(PSTR("Limit triggered <Check and Reset>")); break;
-      }
-    // All other non-critical error codes are less than zero. These are defined to be any
-    // error that is not susceptible to the alarm mode. Typically settings responses.
-    } else {
-      switch(status_code) {
-        case STATUS_SETTING_INVALID:
-        printPgmString(PSTR("Invalid setting statement")); break;
       case STATUS_SETTING_STEPS_NEG:
       printPgmString(PSTR("Steps/mm must be > 0.0")); break;
       case STATUS_SETTING_STEP_PULSE_MIN:
       printPgmString(PSTR("Step pulse must be >= 3 microseconds")); break;
-      }
+      case STATUS_SETTING_READ_FAIL:
+      printPgmString(PSTR("Failed to read EEPROM settings. Using defaults")); break;
     }
     printPgmString(PSTR("\r\n"));
   }
 }
 
 
-// Prints Grbl warning messages. This serves as a centralized method to provide additional
+// Prints miscellaneous messages. This serves as a centralized method to provide additional
-// user feedback for things that do not pass through the protocol_execute_line() function.
+// user feedback for things that do not pass through the protocol_execute_line() function
-// This includes things like initialization checks or setup warnings when features are
+// and are not errors or confirmations, such as setup warnings.
-// enabled. This function maybe called from anywhere in Grbl at the point of concern.
+void protocol_misc_message(uint8_t message_code)
-void protocol_warning_message(int8_t warning_code)
 {
-  // TODO: Install silence warning messages option in settings
+  // TODO: Install silence misc messages option in settings
-  printPgmString(PSTR("warning: "));
+  switch(message_code) {
-  switch(warning_code) {
+    case MESSAGE_HOMING_ENABLE:
-    case WARNING_HOMING_ENABLE:
+      printPgmString(PSTR("warning: Install all axes limit switches before use")); break;
-      printPgmString(PSTR("Install all axes limit switches before use")); break;
-    case WARNING_SETTING_READ_FAIL:
-      printPgmString(PSTR("Failed to read EEPROM settings. Using defaults")); break;
   }
   printPgmString(PSTR("\r\n"));
 }
@@ -181,7 +167,6 @@ void protocol_execute_runtime()
     
     // System alarm. Something has gone wrong. Disable everything until system reset.
     if (rt_exec & EXEC_ALARM) {
-      protocol_status_message(STATUS_HARD_LIMIT);
       while (bit_isfalse(sys.execute,EXEC_RESET)) { sleep_mode(); }
       bit_false(sys.execute,EXEC_ALARM);
     } 
@@ -223,7 +208,7 @@ void protocol_execute_runtime()
 
 
 // Executes one line of input according to protocol
-int8_t protocol_execute_line(char *line) 
+uint8_t protocol_execute_line(char *line) 
 {     
   if(line[0] == '$') {
   
@@ -255,6 +240,9 @@ int8_t protocol_execute_line(char *line)
 
   } else {
     return(gc_execute_line(line));    // Everything else is gcode
+    // TODO: Install option to set system alarm upon any error code received back from the
+    // the g-code parser. This is a common safety feature on CNCs to help prevent crashes
+    // if the g-code doesn't perform as intended.
   }
 }
 

protocol.h

@@ -21,28 +21,31 @@
 #ifndef protocol_h
 #define protocol_h
 
-
+// Line buffer size from the serial input stream to be executed.
+// NOTE: Not a problem except for extreme cases, but the line buffer size can be too small
+// and g-code blocks can get truncated. Officially, the g-code standards support up to 256
+// characters. In future versions, this will be increased, when we know how much extra
+// memory space we can invest into here or we re-write the g-code parser not to have his 
+// buffer.
 #define LINE_BUFFER_SIZE 50
 
 // Define Grbl status codes.
 #define STATUS_OK 0
-// Critical error codes. Greater than zero.
 #define STATUS_BAD_NUMBER_FORMAT 1
 #define STATUS_EXPECTED_COMMAND_LETTER 2
 #define STATUS_UNSUPPORTED_STATEMENT 3
 #define STATUS_FLOATING_POINT_ERROR 4
 #define STATUS_MODAL_GROUP_VIOLATION 5
 #define STATUS_INVALID_STATEMENT 6
-#define STATUS_SETTING_DISABLED 7
+#define STATUS_HARD_LIMIT 7
-#define STATUS_HARD_LIMIT 8
+#define STATUS_SETTING_DISABLED 8
-// Non-critical error codes. Less than zero.
+#define STATUS_SETTING_STEPS_NEG 9
-#define STATUS_SETTING_INVALID -1
+#define STATUS_SETTING_STEP_PULSE_MIN 10
-#define STATUS_SETTING_STEPS_NEG -2
+#define STATUS_SETTING_READ_FAIL 11
-#define STATUS_SETTING_STEP_PULSE_MIN -3
+
+// Define Grbl misc message codes
+#define MESSAGE_HOMING_ENABLE 1
 
-// Define Grbl warning message codes
-#define WARNING_HOMING_ENABLE 1
-#define WARNING_SETTING_READ_FAIL 2
 
 // Initialize the serial protocol
 void protocol_init();
@@ -52,12 +55,15 @@ void protocol_init();
 void protocol_process();
 
 // Executes one line of input according to protocol
-int8_t protocol_execute_line(char *line);
+uint8_t protocol_execute_line(char *line);
 
 // Checks and executes a runtime command at various stop points in main program
 void protocol_execute_runtime();
 
-// Prints any warning messages.
+// Prints Grbl's status messages.
-void protocol_warning_message(int8_t warning_code);
+void protocol_status_message(uint8_t status_code);
+
+// Prints any misc messages.
+void protocol_misc_message(uint8_t message_code);
 
 #endif

serial.c

@@ -26,8 +26,7 @@
 #include <avr/sleep.h>
 #include "serial.h"
 #include "config.h"
-#include "stepper.h"
+#include "motion_control.h"
-#include "spindle_control.h"
 #include "nuts_bolts.h"
 #include "protocol.h"
 
@@ -166,16 +165,8 @@ ISR(USART_RX_vect)
     case CMD_CYCLE_START:   sys.execute |= EXEC_CYCLE_START; break; // Set as true
     case CMD_FEED_HOLD:     sys.execute |= EXEC_FEED_HOLD; break; // Set as true
     case CMD_RESET:
-      sys.execute |= EXEC_ALARM; // Set alarm to allow subsystem disable for certain settings.
-      
-      // TODO: When Grbl system status is installed, set position lost state if the cycle is active.
-      // if (sys.cycle_start) { POSITION LOST } 
-      
       // Immediately force stepper and spindle subsystem idle at an interrupt level.
-      if (!(sys.execute & EXEC_RESET)) { // Force stop only first time.
+      if (!(sys.execute & EXEC_RESET)) { mc_alarm(); } // Stop only first time.
-        st_go_idle();  
-        spindle_stop();
-      }
       sys.execute |= EXEC_RESET; // Set as true
       break;
     default: // Write character to buffer    

settings.c

@@ -148,7 +148,7 @@ void settings_dump() {
 
 // Parameter lines are on the form '$4=374.3' or '$' to dump current settings
 // NOTE: Assumes '$' already exists in line[0], which is checked by protocol.c.
-int8_t settings_execute_line(char *line) {
+uint8_t settings_execute_line(char *line) {
   uint8_t char_counter = 1; 
 //  unsigned char letter;
   float parameter, value;
@@ -173,16 +173,16 @@ int8_t settings_execute_line(char *line) {
 //     
 //   } else {
   if(!read_float(line, &char_counter, &parameter)) {
-    return(STATUS_SETTING_INVALID);
+    return(STATUS_BAD_NUMBER_FORMAT);
   }
   if(line[char_counter++] != '=') { 
-    return(STATUS_SETTING_INVALID); 
+    return(STATUS_UNSUPPORTED_STATEMENT); 
   }
   if(!read_float(line, &char_counter, &value)) {
-    return(STATUS_SETTING_INVALID);
+    return(STATUS_BAD_NUMBER_FORMAT);
   }
   if(line[char_counter] != 0) { 
-    return(STATUS_SETTING_INVALID); 
+    return(STATUS_UNSUPPORTED_STATEMENT); 
   }
   return(settings_store_setting(parameter, value));
 //   }
@@ -247,7 +247,7 @@ int read_settings() {
 }
 
 // A helper method to set settings from command line
-int8_t settings_store_setting(int parameter, float value) {
+uint8_t settings_store_setting(int parameter, float value) {
   switch(parameter) {
     case 0: case 1: case 2:
       if (value <= 0.0) { return(STATUS_SETTING_STEPS_NEG); } 
@@ -279,7 +279,7 @@ int8_t settings_store_setting(int parameter, float value) {
     case 13:
       if (value) { 
         settings.flags |= BITFLAG_HOMING_ENABLE; 
-        protocol_warning_message(WARNING_HOMING_ENABLE);
+        protocol_misc_message(MESSAGE_HOMING_ENABLE);
       } else { settings.flags &= ~BITFLAG_HOMING_ENABLE; }
       break;
     case 14: settings.homing_dir_mask = trunc(value); break;
@@ -293,7 +293,7 @@ int8_t settings_store_setting(int parameter, float value) {
        break;
     case 20: settings.decimal_places = round(value); break;
     default: 
-      return(STATUS_SETTING_INVALID);
+      return(STATUS_INVALID_STATEMENT);
   }
   write_settings();
   return(STATUS_OK);
@@ -302,7 +302,7 @@ int8_t settings_store_setting(int parameter, float value) {
 // Initialize the config subsystem
 void settings_init() {
   if(!read_settings()) {
-    protocol_warning_message(WARNING_SETTING_READ_FAIL);
+    protocol_status_message(STATUS_SETTING_READ_FAIL);
     settings_reset(true);
     write_settings();
     settings_dump();

settings.h

@@ -66,10 +66,10 @@ void settings_init();
 void settings_dump();
 
 // Handle settings command
-int8_t settings_execute_line(char *line);
+uint8_t settings_execute_line(char *line);
 
 // A helper method to set new settings from command line
-int8_t settings_store_setting(int parameter, float value);
+uint8_t settings_store_setting(int parameter, float value);
 
 // int8_t settings_execute_startup();
 

stepper.c

@@ -113,7 +113,7 @@ void st_go_idle()
   // Force stepper dwell to lock axes for a defined amount of time to ensure the axes come to a complete
   // stop and not drift from residual inertial forces at the end of the last movement.
   delay_ms(settings.stepper_idle_lock_time);
-  // Disable steppers only upon system alarm activated or by user setting to keep enabled.
+  // Disable steppers only upon system alarm activated or by user setting to not be kept enabled.
   if ((settings.stepper_idle_lock_time != 0xff) || bit_istrue(sys.execute,EXEC_ALARM)) {
     STEPPERS_DISABLE_PORT |= (1<<STEPPERS_DISABLE_BIT);
   }