/* protocol.c - controls Grbl execution protocol and procedures Part of Grbl Copyright (c) 2011-2015 Sungeun K. Jeon Copyright (c) 2009-2011 Simen Svale Skogsrud Grbl 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. Grbl 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. You should have received a copy of the GNU General Public License along with Grbl. If not, see . */ #include "grbl.h" // Define different comment types for pre-parsing. #define COMMENT_NONE 0 #define COMMENT_TYPE_PARENTHESES 1 #define COMMENT_TYPE_SEMICOLON 2 static char line[LINE_BUFFER_SIZE]; // Line to be executed. Zero-terminated. // Directs and executes one line of formatted input from protocol_process. While mostly // incoming streaming g-code blocks, this also directs and executes Grbl internal commands, // such as settings, initiating the homing cycle, and toggling switch states. static void protocol_execute_line(char *line) { protocol_execute_realtime(); // Runtime command check point. if (sys.abort) { return; } // Bail to calling function upon system abort #ifdef REPORT_ECHO_LINE_RECEIVED report_echo_line_received(line); #endif if (line[0] == 0) { // Empty or comment line. Send status message for syncing purposes. report_status_message(STATUS_OK); } else if (line[0] == '$') { // Grbl '$' system command report_status_message(system_execute_line(line)); } else if (sys.state == STATE_ALARM) { // Everything else is gcode. Block if in alarm mode. report_status_message(STATUS_ALARM_LOCK); } else { // Parse and execute g-code block! report_status_message(gc_execute_line(line)); } } /* GRBL PRIMARY LOOP: */ void protocol_main_loop() { // ------------------------------------------------------------ // Complete initialization procedures upon a power-up or reset. // ------------------------------------------------------------ // Print welcome message report_init_message(); // Check for and report alarm state after a reset, error, or an initial power up. if (sys.state == STATE_ALARM) { report_feedback_message(MESSAGE_ALARM_LOCK); } else { // All systems go! But first check for safety door. if (system_check_safety_door_ajar()) { bit_true(sys_rt_exec_state, EXEC_SAFETY_DOOR); protocol_execute_realtime(); // Enter safety door mode. Should return as IDLE state. } else { sys.state = STATE_IDLE; // Set system to ready. Clear all state flags. } system_execute_startup(line); // Execute startup script. } // --------------------------------------------------------------------------------- // Primary loop! Upon a system abort, this exits back to main() to reset the system. // --------------------------------------------------------------------------------- uint8_t comment = COMMENT_NONE; uint8_t char_counter = 0; uint8_t c; for (;;) { // Process one line of incoming serial data, as the data becomes available. Performs an // initial filtering by removing spaces and comments and capitalizing all letters. // NOTE: While comment, spaces, and block delete(if supported) handling should technically // be done in the g-code parser, doing it here helps compress the incoming data into Grbl's // line buffer, which is limited in size. The g-code standard actually states a line can't // exceed 256 characters, but the Arduino Uno does not have the memory space for this. // With a better processor, it would be very easy to pull this initial parsing out as a // seperate task to be shared by the g-code parser and Grbl's system commands. while((c = serial_read()) != SERIAL_NO_DATA) { if ((c == '\n') || (c == '\r')) { // End of line reached line[char_counter] = 0; // Set string termination character. protocol_execute_line(line); // Line is complete. Execute it! comment = COMMENT_NONE; char_counter = 0; } else { if (comment != COMMENT_NONE) { // Throw away all comment characters if (c == ')') { // End of comment. Resume line. But, not if semicolon type comment. if (comment == COMMENT_TYPE_PARENTHESES) { comment = COMMENT_NONE; } } } else { if (c <= ' ') { // Throw away whitepace and control characters } else if (c == '/') { // Block delete NOT SUPPORTED. Ignore character. // NOTE: If supported, would simply need to check the system if block delete is enabled. } else if (c == '(') { // Enable comments flag and ignore all characters until ')' or EOL. // NOTE: This doesn't follow the NIST definition exactly, but is good enough for now. // In the future, we could simply remove the items within the comments, but retain the // comment control characters, so that the g-code parser can error-check it. comment = COMMENT_TYPE_PARENTHESES; } else if (c == ';') { // NOTE: ';' comment to EOL is a LinuxCNC definition. Not NIST. comment = COMMENT_TYPE_SEMICOLON; // TODO: Install '%' feature // } else if (c == '%') { // Program start-end percent sign NOT SUPPORTED. // NOTE: This maybe installed to tell Grbl when a program is running vs manual input, // where, during a program, the system auto-cycle start will continue to execute // everything until the next '%' sign. This will help fix resuming issues with certain // functions that empty the planner buffer to execute its task on-time. } else if (char_counter >= (LINE_BUFFER_SIZE-1)) { // Detect line buffer overflow. Report error and reset line buffer. report_status_message(STATUS_OVERFLOW); comment = COMMENT_NONE; char_counter = 0; } else if (c >= 'a' && c <= 'z') { // Upcase lowercase line[char_counter++] = c-'a'+'A'; } else { line[char_counter++] = c; } } } } // If there are no more characters in the serial read buffer to be processed and executed, // this indicates that g-code streaming has either filled the planner buffer or has // completed. In either case, auto-cycle start, if enabled, any queued moves. protocol_auto_cycle_start(); protocol_execute_realtime(); // Runtime command check point. if (sys.abort) { return; } // Bail to main() program loop to reset system. } return; /* Never reached */ } // Executes run-time commands, when required. This is called from various check points in the main // program, primarily where there may be a while loop waiting for a buffer to clear space or any // point where the execution time from the last check point may be more than a fraction of a second. // This is a way to execute realtime commands asynchronously (aka multitasking) with grbl's g-code // parsing and planning functions. This function also serves as an interface for the interrupts to // set the system realtime flags, where only the main program handles them, removing the need to // define more computationally-expensive volatile variables. This also provides a controlled way to // execute certain tasks without having two or more instances of the same task, such as the planner // recalculating the buffer upon a feedhold or override. // NOTE: The sys_rt_exec_state variable flags are set by any process, step or serial interrupts, pinouts, // limit switches, or the main program. void protocol_execute_realtime() { uint8_t rt_exec; // Temp variable to avoid calling volatile multiple times. do { // If system is suspended, suspend loop restarts here. // Check and execute alarms. rt_exec = sys_rt_exec_alarm; // Copy volatile sys_rt_exec_alarm. if (rt_exec) { // Enter only if any bit flag is true // System alarm. Everything has shutdown by something that has gone severely wrong. Report // the source of the error to the user. If critical, Grbl disables by entering an infinite // loop until system reset/abort. sys.state = STATE_ALARM; // Set system alarm state if (rt_exec & EXEC_ALARM_HARD_LIMIT) { report_alarm_message(ALARM_HARD_LIMIT_ERROR); } else if (rt_exec & EXEC_ALARM_SOFT_LIMIT) { report_alarm_message(ALARM_SOFT_LIMIT_ERROR); } else if (rt_exec & EXEC_ALARM_ABORT_CYCLE) { report_alarm_message(ALARM_ABORT_CYCLE); } else if (rt_exec & EXEC_ALARM_PROBE_FAIL) { report_alarm_message(ALARM_PROBE_FAIL); } else if (rt_exec & EXEC_ALARM_HOMING_FAIL) { report_alarm_message(ALARM_HOMING_FAIL); } // Halt everything upon a critical event flag. Currently hard and soft limits flag this. if (rt_exec & EXEC_CRITICAL_EVENT) { report_feedback_message(MESSAGE_CRITICAL_EVENT); bit_false_atomic(sys_rt_exec_state,EXEC_RESET); // Disable any existing reset do { // Nothing. Block EVERYTHING until user issues reset or power cycles. Hard limits // typically occur while unattended or not paying attention. Gives the user time // to do what is needed before resetting, like killing the incoming stream. The // same could be said about soft limits. While the position is not lost, the incoming // stream could be still engaged and cause a serious crash if it continues afterwards. // TODO: Allow status reports during a critical alarm. Still need to think about implications of this. // if (sys_rt_exec_state & EXEC_STATUS_REPORT) { // report_realtime_status(); // bit_false_atomic(sys_rt_exec_state,EXEC_STATUS_REPORT); // } } while (bit_isfalse(sys_rt_exec_state,EXEC_RESET)); } bit_false_atomic(sys_rt_exec_alarm,0xFF); // Clear all alarm flags } // Check amd execute realtime commands rt_exec = sys_rt_exec_state; // Copy volatile sys_rt_exec_state. if (rt_exec) { // Enter only if any bit flag is true // Execute system abort. if (rt_exec & EXEC_RESET) { sys.abort = true; // Only place this is set true. return; // Nothing else to do but exit. } // Execute and serial print status if (rt_exec & EXEC_STATUS_REPORT) { report_realtime_status(); bit_false_atomic(sys_rt_exec_state,EXEC_STATUS_REPORT); } // Execute hold states. // NOTE: The math involved to calculate the hold should be low enough for most, if not all, // operational scenarios. Once hold is initiated, the system enters a suspend state to block // all main program processes until either reset or resumed. if (rt_exec & (EXEC_MOTION_CANCEL | EXEC_FEED_HOLD | EXEC_SAFETY_DOOR)) { // TODO: CHECK MODE? How to handle this? Likely nothing, since it only works when IDLE and then resets Grbl. // State check for allowable states for hold methods. if ((sys.state == STATE_IDLE) || (sys.state & (STATE_CYCLE | STATE_HOMING | STATE_MOTION_CANCEL | STATE_HOLD | STATE_SAFETY_DOOR))) { // If in CYCLE state, all hold states immediately initiate a motion HOLD. if (sys.state == STATE_CYCLE) { st_update_plan_block_parameters(); // Notify stepper module to recompute for hold deceleration. sys.suspend = SUSPEND_ENABLE_HOLD; // Initiate holding cycle with flag. } // If IDLE, Grbl is not in motion. Simply indicate suspend ready state. if (sys.state == STATE_IDLE) { sys.suspend = SUSPEND_ENABLE_READY; } // Execute and flag a motion cancel with deceleration and return to idle. Used primarily by probing cycle // to halt and cancel the remainder of the motion. if (rt_exec & EXEC_MOTION_CANCEL) { // MOTION_CANCEL only occurs during a CYCLE, but a HOLD and SAFETY_DOOR may been initiated beforehand // to hold the CYCLE. If so, only flag that motion cancel is complete. if (sys.state == STATE_CYCLE) { sys.state = STATE_MOTION_CANCEL; } sys.suspend |= SUSPEND_MOTION_CANCEL; // Indicate motion cancel when resuming. Special motion complete. } // Execute a feed hold with deceleration, only during cycle. if (rt_exec & EXEC_FEED_HOLD) { // Block SAFETY_DOOR state from prematurely changing back to HOLD. if (bit_isfalse(sys.state,STATE_SAFETY_DOOR)) { sys.state = STATE_HOLD; } } // Execute a safety door stop with a feed hold, only during a cycle, and disable spindle/coolant. // NOTE: Safety door differs from feed holds by stopping everything no matter state, disables powered // devices (spindle/coolant), and blocks resuming until switch is re-engaged. The power-down is // executed here, if IDLE, or when the CYCLE completes via the EXEC_CYCLE_STOP flag. if (rt_exec & EXEC_SAFETY_DOOR) { report_feedback_message(MESSAGE_SAFETY_DOOR_AJAR); // If already in active, ready-to-resume HOLD, set CYCLE_STOP flag to force de-energize. // NOTE: Only temporarily sets the 'rt_exec' variable, not the volatile 'rt_exec_state' variable. if (sys.suspend & SUSPEND_ENABLE_READY) { bit_true(rt_exec,EXEC_CYCLE_STOP); } sys.suspend |= SUSPEND_ENERGIZE; sys.state = STATE_SAFETY_DOOR; } } bit_false_atomic(sys_rt_exec_state,(EXEC_MOTION_CANCEL | EXEC_FEED_HOLD | EXEC_SAFETY_DOOR)); } // Execute a cycle start by starting the stepper interrupt to begin executing the blocks in queue. if (rt_exec & EXEC_CYCLE_START) { // Block if called at same time as the hold commands: feed hold, motion cancel, and safety door. // Ensures auto-cycle-start doesn't resume a hold without an explicit user-input. if (!(rt_exec & (EXEC_FEED_HOLD | EXEC_MOTION_CANCEL | EXEC_SAFETY_DOOR))) { // Cycle start only when IDLE or when a hold is complete and ready to resume. // NOTE: SAFETY_DOOR is implicitly blocked. It reverts to HOLD when the door is closed. if ((sys.state == STATE_IDLE) || ((sys.state & (STATE_HOLD | STATE_MOTION_CANCEL)) && (sys.suspend & SUSPEND_ENABLE_READY))) { // Re-energize powered components, if disabled by SAFETY_DOOR. if (sys.suspend & SUSPEND_ENERGIZE) { // Delayed Tasks: Restart spindle and coolant, delay to power-up, then resume cycle. if (gc_state.modal.spindle != SPINDLE_DISABLE) { spindle_set_state(gc_state.modal.spindle, gc_state.spindle_speed); delay_ms(SAFETY_DOOR_SPINDLE_DELAY); // TODO: Blocking function call. Need a non-blocking one eventually. } if (gc_state.modal.coolant != COOLANT_DISABLE) { coolant_set_state(gc_state.modal.coolant); delay_ms(SAFETY_DOOR_COOLANT_DELAY); // TODO: Blocking function call. Need a non-blocking one eventually. } // TODO: Install return to pre-park position. } // Start cycle only if queued motions exist in planner buffer and the motion is not canceled. if (plan_get_current_block() && bit_isfalse(sys.suspend,SUSPEND_MOTION_CANCEL)) { sys.state = STATE_CYCLE; st_prep_buffer(); // Initialize step segment buffer before beginning cycle. st_wake_up(); } else { // Otherwise, do nothing. Set and resume IDLE state. sys.state = STATE_IDLE; } sys.suspend = SUSPEND_DISABLE; // Break suspend state. } } bit_false_atomic(sys_rt_exec_state,EXEC_CYCLE_START); } // Reinitializes the cycle plan and stepper system after a feed hold for a resume. Called by // realtime command execution in the main program, ensuring that the planner re-plans safely. // NOTE: Bresenham algorithm variables are still maintained through both the planner and stepper // cycle reinitializations. The stepper path should continue exactly as if nothing has happened. // NOTE: EXEC_CYCLE_STOP is set by the stepper subsystem when a cycle or feed hold completes. if (rt_exec & EXEC_CYCLE_STOP) { if (sys.state & (STATE_HOLD | STATE_SAFETY_DOOR) && !(sys.soft_limit)) { // Hold complete. Set to indicate ready to resume. Remain in HOLD or DOOR states until user // has issued a resume command or reset. if (sys.suspend & SUSPEND_ENERGIZE) { // De-energize system if safety door has been opened. spindle_stop(); coolant_stop(); } bit_true(sys.suspend,SUSPEND_ENABLE_READY); } else { // Motion is complete. Includes CYCLE, HOMING, and MOTION_CANCEL states. sys.suspend = SUSPEND_DISABLE; sys.state = STATE_IDLE; } bit_false_atomic(sys_rt_exec_state,EXEC_CYCLE_STOP); } } // Overrides flag byte (sys.override) and execution should be installed here, since they // are realtime and require a direct and controlled interface to the main stepper program. // Reload step segment buffer if (sys.state & (STATE_CYCLE | STATE_HOLD | STATE_MOTION_CANCEL | STATE_SAFETY_DOOR | STATE_HOMING)) { st_prep_buffer(); } // If safety door was opened, actively check when safety door is closed and ready to resume. // NOTE: This unlocks the SAFETY_DOOR state to a HOLD state, such that CYCLE_START can activate a resume. if (sys.state == STATE_SAFETY_DOOR) { if (bit_istrue(sys.suspend,SUSPEND_ENABLE_READY)) { if (!(system_check_safety_door_ajar())) { sys.state = STATE_HOLD; // Update to HOLD state to indicate door is closed and ready to resume. } } } } while(sys.suspend); // Check for system suspend state before exiting. } // Block until all buffered steps are executed or in a cycle state. Works with feed hold // during a synchronize call, if it should happen. Also, waits for clean cycle end. void protocol_buffer_synchronize() { // If system is queued, ensure cycle resumes if the auto start flag is present. protocol_auto_cycle_start(); do { protocol_execute_realtime(); // Check and execute run-time commands if (sys.abort) { return; } // Check for system abort } while (plan_get_current_block() || (sys.state == STATE_CYCLE)); } // Auto-cycle start has two purposes: 1. Resumes a plan_synchronize() call from a function that // requires the planner buffer to empty (spindle enable, dwell, etc.) 2. As a user setting that // automatically begins the cycle when a user enters a valid motion command manually. This is // intended as a beginners feature to help new users to understand g-code. It can be disabled // as a beginner tool, but (1.) still operates. If disabled, the operation of cycle start is // manually issuing a cycle start command whenever the user is ready and there is a valid motion // command in the planner queue. // NOTE: This function is called from the main loop, buffer sync, and mc_line() only and executes // when one of these conditions exist respectively: There are no more blocks sent (i.e. streaming // is finished, single commands), a command that needs to wait for the motions in the buffer to // execute calls a buffer sync, or the planner buffer is full and ready to go. void protocol_auto_cycle_start() { bit_true_atomic(sys_rt_exec_state, EXEC_CYCLE_START); }