gnea/grbl
Grbl
grbl is a CNC machine control system that translates G-code into precise hardware pulses to drive motors and tools for automated fabrication. It functions as a motion controller that manages the translation of standard commands into physical movement through asynchronous operation.
The system includes a motion planning optimizer that calculates acceleration and deceleration curves using a look-ahead buffer to ensure fluid cornering and jerk-free movement. It features a dedicated laser engraving workflow that dynamically scales laser power based on movement speed to maintain consistent energy delivery.
The project covers a broad range of operational capabilities, including tool calibration via probing and customizable homing cycles, and hardware safety through the enforcement of soft limits and safety park routines. It provides real-time machine status reporting, spindle speed control, and the ability to override feed rates during job execution. System configurations and coordinate offsets are maintained across power cycles using non-volatile memory.
Features
- CNC Machine Controllers - Translates G-code into precise hardware pulses to drive motors and tools for automated fabrication.
- G-Code Interpreters - Interprets a subset of the LinuxCNC G-code standard to control three-axis CNC machines with linear and arc motions.
- Look-Ahead Trajectory Planning - Examines upcoming moves in a look-ahead buffer to compute smooth acceleration and deceleration curves.
- Look-Ahead Acceleration Planners - Examines up to 16 future moves to compute smooth velocity profiles for eliminating jerky transitions and delivering jitter-free acceleration.
- Homing Cycles - Runs a configurable homing cycle that searches for limit switches to establish a known machine origin.
- Real-Time Feed Rate Overrides - Provides real-time feed rate and spindle speed overrides during active job execution with sub-millisecond response.
- Safety Parking Routines - Runs homing cycles, checks soft limits, parks at safety doors, and stores coordinates for reliable unattended operation.
- Tool Probing Calibrations - Executes straight-probe G-code commands to measure workpiece position and set tool length offsets.
- Motion Planning Interrupts - Generates precise stepper motor pulses directly from hardware timer interrupts for real-time motion control.
- Embedded G-Code Firmware - Provides embedded real-time firmware that parses G-code and drives CNC and laser engraving hardware.
- Trapezoidal Velocity Profilers - Implements trapezoidal velocity profiling for smooth acceleration and deceleration in CNC motion control.
- Machine Status Reporters - Outputs structured status reports and numeric error codes with unique prefixes for GUIs to parse machine state.
- G-Code Syntax Validators - Simulates program execution without moving the machine to validate G-code syntax and detect potential errors.
- EEPROM Coordinate Persistence - Saves work coordinate systems and predefined positions to EEPROM so they survive power cycles.
- Feed-Rate-Proportional Laser Power Scaling - Scales laser output proportionally to current feed rate for consistent energy delivery during acceleration and deceleration.
- Velocity-Proportional Laser Power Scaling - Scales laser output with travel speed during continuous moves to prevent burnt corners on low-acceleration machines.
- Laser Engraving Workflows - Dynamically scales laser power with movement speed to maintain consistent energy delivery during engraving.
- Continuous Motion Laser Modes - Moves continuously through consecutive G1/G2/G3 moves while scaling laser power with travel speed to prevent burnt corners.
- Cutting-Move Laser Activations - Activates the laser exclusively during G1, G2, or G3 motions and disables it during rapid moves and probe cycles.
- In-Motion Power Updates - Updates laser power instantaneously across consecutive G-code moves without stopping the machine for spindle speed changes.
- Laser Power Mode Toggles - Switches between constant and dynamic laser power modes to match cutting or engraving requirements without pausing motion.
- Manual Jogging Controls - Moves axes independently of the G-code parser using low-latency jogging commands for manual control.
- Non-Volatile Setting Persistence - Persists coordinate offsets and system configurations to EEPROM for state retention across power cycles.
- Structured Status Reporters - Reports structured status and error codes for GUI parsing and supports live feed rate overrides.
- Soft Limit Enforcers - Enforces soft limits, safety park routines, and homing cycles for reliable unattended CNC operation.
