G-code
Introduction
G-code is the instruction set generated by the slicer which tells the printer what to do.
The AON-M2 runs using a firmware based off of the popular Marlin firmware project, and many of the G-code commands are similar in functionality, but with subtle yet important differences. Please refer to this manual for all G-code commands to be run on the M2.
While it is not necessary to be familiar with the intricacies of G-code for day-to-day usage, the aspiring power user will find it invaluable to develop a solid grasp of the fundamentals for developmental work, detailed optimization, or advanced troubleshooting.
G-code Cheat Sheet
The most frequently used G-code commands are listed below.
G-code input is case-sensitive. Make sure to capitalize all letters.
| G-code | Description |
|---|---|
| G1 | Linear Move/Extrude |
| G28 | Home Axes |
| G29 | Probe Bed |
| M104 | Set Hotend Temperature |
| M140 | Set Bed Temperature |
| M290 | Adjust Z offset |
| M500 | Save to EEPROM |
| M501 | Restore from EEPROM |
| M502 | Reset EEPROM |
Detailed Reference
G commands
G0/G1 Linear Move
Performs a linear move between two points at a certain speed while extruding material.
Parameters
G1 [Xnnn] [Ynnn] [Znnn] [Ennn] [Fnnn]
[Xnnn] where nnn is a co-ordinate point on the X axis.
[Ynnn] where nnn is a co-ordinate point on the Y axis.
[Znnn] where nnn is a co-ordinate point on the Z axis.
[Ennn] where nnn is a value in mm determining how many mm of filament to extrude during the movement.
[Fnnn] where nnn is the speed of movement in mm/min.
Examples
G1 X50.2 Y10.7 E2.6 F1800 move to XY co-ordinate (50.2,10.7) in a straight line at 1800mm/min velocity while extruding 2.6mm of filament.
G28 Home Axes
Homes a specified axes or all axes.
Parameters
G28 [X] [Y] [Z]
Examples
G28 X Y Homes X and Y axes.
G28 Home all axes.
G29 Auto Bed Leveling
Initiates auto bed leveling with the nozzle probe. Requires G28 beforehand. This will
probe the bed with a 5x5 grid, then move the active tool to the front corner of it's
respective home side of the bed, i.e. when T0 is selected, it will move to the
front left of the bed, and when T1 is selected, it will move to the front right of
the bed.
After the probing process is complete, you should always verify that the nozzle is not
making firm contact with the bed or depressing the probe mechanism. Adjustments should
be made using M290.
Parameters
G29
G90 Absolute Positioning
Sets G-code interpretation to absolute position mode where positions are given as absolute values in co-ordinate space.
Parameters
G90
G91 Relative Positioning
Sets G-code interpretation to relative position mode where the next position is calculated relative to the last known position in co-ordinate space.
Parameters
G91
G92 Set Position
Manually sets the current position to the values specified by this command. Homing
(G28) and probing (G29) will invalidate any set values.
!!! warning Only use this feature if you absolutely know what you are doing!
Parameters
G92 [Ennn] [Xnnn] [Ynnn] [Znnn]
[Ennn] where nnn is the extruder position, in mm
[Xnnn] where nnn is the X position, in mm
[Ynnn] where nnn is the Y position, in mm
[Znnn] where nnn is the Z position, in mm
Examples
G92 X50 Y50 Z1 sets the current known position to X=50, Y=50, Z=1 regardless of the
actual physical location of the axes.
T0/T1 Select Active Toolhead
Changes the active toolhead. This will move the initial toolhead back to its parked position, and enable the new toolhead mesh and Z offset.
Parameters
[Tx]
[Tx] where x is an index between 0 or 1 corresponding to the desired tool.
Examples
T1 changes the active toolhead to T1 (right extruder). If the active toolhead is
already T1, does nothing.
M commands
M0 Stop
Pauses the printer and waits for user input, or pauses for a fixed period of time.
Parameters
M0 [Snnn]
[Snnn] where nnn denotes the pause time length in seconds.
Examples
M0 causes the printer to stop and wait until an M108 command is sent.
M0 S5 will cause the printer to stop for 5 seconds
M82 Set E to Absolute
Overrides G91 to set just the extruder into absolute co-ordinates mode. If used, ensure that it is disabled after use to avoid unintended retractions.
Parameters
M82
Examples
G91 ;sets all axes to relative mode
M82 ;sets E to absolute mode, all other axes remain in relative mode
M83 Set E to Relative
Overrides G90 to set just the extruder into relative co-ordinates mode.
Parameters
M83
Examples
G90 ;sets all axes to absolute mode
M83 ;sets E to relative mode, all other axes remain in absolute mode
M92 Set Steps Per mm
Sets the value of motor steps to be sent per mm of travel.
Note
The steps-per-mm value for the movement axes (XYZ) are determined by the hardware and should not be modified. Only to be used for recalibrating the Extruder axes. Extruder flow adjustment is preferably done through the slicer settings.
Parameters
M92 [Ennn] [Tx] [Xnnn] [Ynnn] [Znnn]
[Ennn] where nnn is the steps-per-mm for the extruder axis. 640 by default on the M2.
[Tx] where x can be 0 or 1 to set independent steps-per-mm for each toolhead.
[Xnnn] where nnn is the steps-per-mm for the X axis. 40 by default on the M2.
[Ynnn] where nnn is the steps-per-mm for the Y axis. 40 by default on the M2.
[Znnn] where nnn is the steps-per-mm for the Z axis. 400 by default on the M2.
Examples
M92 E645 T1 sets the T1 extruder steps-per-mm to 645.
M104 Set Hot End Temperature
Sets the hot end/chamber target temperature and continues to the next command.
Parameters
M104 [Tx] [Snnn]
[Tx] where x is 0 (T0), 1 (T1), or 2 (Chamber Heater)
[Snnn] where nnn is the target temperature in °C.
Examples
M104 T1 S250 Set T1 to 250°C
M104 T2 S120 Set chamber temperature to 120°C
M105 Report Temperatures
Report all temperatures.
Parameters
M105
Examples
M105 returns temperature values for all sensors (T0, T1, chamber, bed)
M106 Set Fan Speeds
Turns on and set fan speeds via PWM.
Parameters
M106 [Px] [Snnn]
[Px] where x is an index of 0, 1, or 2. The M2 only has a chamber fan, accessible
as index 2.
[Snnn] where nnn is a value between 0-255 for PWM.
Examples
M106 P2 S255 turn chamber heater fan on to full power.
M107 Turn Fan Off
Turns fans off.
Parameters
M107 [Px]
[Px] where x is an index of 0, 1, or 2. The M2 only has a chamber fan, accessible
as index 2.
Examples
M107 P2 turns chamber heater fans off.
M108 Break and Continue
Continues after a pause (M0) command. Can also override the waiting period for M109 and M190.
Parameters
M108
Examples
M0 ;pauses print job
M108 ;resumes print job
M109 Set Hot End Temperature and Wait
Sets the hot end/chamber target temperature and waits until target temperature is reached before continuing to the next command.
Parameters
M109 [Tx] [Snnn]
[Tx] where x is 0 (T0), 1 (T1), or 2 (Chamber Heater)
[Snnn] where nnn is the target temperature in °C.
Examples
M109 T1 S250 Set T1 to 250°C
M109 T2 S120 Set chamber temperature to 120°C
M111 Debug Mode
Sets advanced debugging outputs.
Parameters
M111 [Sx]
[Sx] where x is a binary summation of the desired debug bits from the following chart:
| Bits | Name | Description |
|---|---|---|
| 1 | ECHO | Echo all parser commands |
| 2 | INFO | Extra info messages |
| 4 | ERRORS | Extra error messages |
| 8 | DRYRUN | Print without extrusion |
| 16 | COMM | Communications |
| 32 | LEVELING | Extra homing/probing info |
Examples
M111 S35 turns on ECHO, INFO, and LEVELING (1+2+32=35)
M112 Emergency Stop
Virtual emergency stop. Immediately stops all movement, shuts down all heaters, stops further communication. Overrides any commands in the buffer, and will require a hard reboot once triggered.
Parameters
M112
Examples
M112 shuts down.
M114 Get Current Position
Gets the current position of the active toolhead.
Parameters
M114
Examples
M114 reports axes co-ordinates of the current active toolhead.
M115 Firmware Info
Outputs current firmware information.
Parameters
M115
Examples
M115 returns a string with information on current firmware.
M119 Endstop Status Report
Outputs current status of all endstops and probes - either open or triggered.
Parameters
M119
Examples
M119 returns set of strings reporting on Xmin, Xmax, Y1, Y2, Z1, Z2, Probe.
M140 Set Bed Temperature
Sets the bed temperature and continues the next command in the buffer.
Parameters
M140 [Snnn]
[Snnn] where nnn is the desired target temperature in °C.
Examples
M140 S150 sets the bed target to 150°C
M190 Set Bed Temperature and Wait
Sets the bed temperature and waits for target to be reached before continuing to the next command in the buffer.
Parameters
M190 [Snnn]
[Snnn] where nnn is the desired target temperature in °C.
Examples
M190 S150 sets the bed target to 150°C
M201 Set Maximum Printing Acceleration
Set global maximum acceleration rate for each movement axes in mm/s2
Parameters
M201 [Ennn] [Xnnn] [Ynnn] [Znnn]
[Ennn] where nnn is an integer value for acceleration in mm/s2. Default value is 10000.
[Xnnn] where nnn is an integer value for acceleration in mm/s2. Default value is 3000.
[Ynnn] where nnn is an integer value for acceleration in mm/s2. Default value is 3000.
[Znnn] where nnn is an integer value for acceleration in mm/s2. Default value is 100.
Examples
M201 X6000 Y6000 Z120 sets X/Y acceleration to 6000 mm/s2 and Z acceleration to 120 mm/s2.
M203 Set Maximum Feedrate
Set maximum travel/feedrate for each movement axes in mm/s.
Watch out!
The default values reach the upper limit of step generation rates on the microcontroller. Setting to higher values WILL result in print failure.
Parameters
M203 [Ennn] [Xnnn] [Ynnn] [Znnn]
[Ennn] where nnn is an integer value for max velocity in mm/s. Default value is 30.
[Xnnn] where nnn is an integer value for max velocity in mm/s. Default value is 499.
[Ynnn] where nnn is an integer value for max velocity in mm/s. Default value is 499.
[Znnn] where nnn is an integer value for max velocity in mm/s. Default value is 10.
Examples
M203 X350 Y350 sets the maximum travel speed of X/Y axes to 350mm/s.
M204 Set Acceleration
Sets acceleration values for different types of axes movements in mm/s2. Cannot exceed global maximums set by M201.
Parameters
M204 [Pnnn] [Rnnn] [Tnnn]
[Pnnn] where nnn is an integer value for printing moves acceleration in mm/s2. Default value is 3000.
[Rnnn] where nnn is an integer value for retraction moves acceleration in mm/s2. Default value is 3000.
[Tnnn] where nnn is an integer value for travel moves acceleration in mm/s2. Default value is 3000.
Examples
M204 P1500 T2500 sets acceleration during printing moves to 1500 and during travel moves to 2500.
M205 Advanced Settings
Sets other miscellaneous advanced variables.
Parameters
M205 [Bnnn] [Ennn] [Snnn] [Tnnn] [Xnnn] [Ynnn] [Znnn]
[Bnnn] where nnn is the minimum allowable print segment time in microseconds.
[Ennn] where nnn is the allowable instantaneous change in velocity for the Extruder in mm/s.
[Snnn] where nnn is the minimum allowable travel rate for printing moves in mm/min.
[Tnnn] where nnn is the minimum allowable travel rate for travel moves in mm/min.
[Xnnn] where nnn is the allowable instantaneous change in velocity for the X axis in mm/s.
[Ynnn] where nnn is the allowable instantaneous change in velocity for the Y axis in mm/s.
[Znnn] where nnn is the allowable instantaneous change in velocity for the Z axis in mm/s.
M206 Set Home Offsets
Applies an offset to the homed zero positions to effectively shift the build area in co-ordinate space.
Parameters
M206 [Xnnn] [Ynnn] [Znnn]
[Xnnn] where nnn is a value in mm.
[Ynnn] where nnn is a value in mm.
[Znnn] where nnn is a value in mm.
Examples
M206 X10 shifts the build area 10mm to the left.
M206 Z0.1 increases gap between nozzle and bed by 0.1mm.
M218 Set Toolhead Offsets
Adjusts the dual extruder offset calibration.
Parameters
M218 [T1] [Xnnn] [Ynnn] [Znnn]
[Xnnn] where nnn is the X offset of T1 relative to T0 in mm. Default is 615.
[Ynnn] where nnn is the Y offset of T1 relative to T0 in mm. Default is 0.
[Znnn] where nnn is the Z offset of T1 relative to T0 in mm. Default is 0.
Examples
M218 T1 X605 Y-0.2 Z0.1 compensates for T1 that prints 10mm too far to the left, 0.2mm too close towards the front, and 0.1mm too far from the bed.
M220 Feedrate Override
During a print, overrides the XYZ axes movement speed by a percentage value.
Parameters
M220 [Snnn]
[Snnn] where nnn is a percentage value between 0-200%
Examples
M220 S125 increases print speed by 25%.
M221 Flowrate Override
During a print, overrides the extruder flow rate by a percentage value.
Parameters
M221 [Snnn]
[Snnn] where nnn is a percentage value between 0-200%
Examples
M221 S95 decreases material flow rate by 5%.
M290 Z Offset Adjustment
Allows for micro-adjustments of toolhead Z offset position. This should be used to calibrate the tool position after probing the bed and is equivalent to "touching off" in machining processes.
Parameters
M290 [Znnn]
[Znnn] where nnn is a value in mm to shift the toolhead location by in the Z axis.
Examples
M290 Z-0.1 decreases the nozzle-to-bed distance by 0.1mm.
M301 Set Hotend PID
Sets PID values for the hot ends and chamber heater. Obtain PID values from M303 and
set using this command. Save with M500.
Parameters
M301 [Ex] [Pnnn] [Innn] [Dnnn]
[Ex] where x is an index of 0 (T0), 1 (T1), or 2 (chamber heater)
[Pnnn] where nnn is the proportional term of the PID.
[Innn] where nnn is the integral term of the PID.
[Dnnn] where nnn is the derivative term of the PID.
Examples
M301 E0 P15 I1 D50 sets the T0 PID to 15, 1, 50.
M303 PID Autotune
Automatically determines the appropriate PID values using the Ziegler-Nichols tuning
method. Optionally, automatically applies PID values without the use of M301.
Parameters
M303 [Cnnn] [Ex] [Snnn] [U]
[Cnn] where nnn is an integer value denoting the number of heating/cooling cycles
[Ex] where x is an index of -1 (Bed), 0 (T0), 1 (T1), or 2 (Chamber)
[Snnn] where nnn is the set point around which to perform the tuning.
[U] optional - automatically applies the PID values to the heater indexed by [Ex]. Save with M500.
Examples
M303 C5 E0 S300 U run PID tuning on T0 around 300°C cycling 5 times and apply PID values immediately.
M304 Set Bed PID
The counterpart to M301 to set PID values for the bed determined by M303.
Parameters
M304 [Pnnn] [Innn] [Dnnn]
[Pnnn] where nnn is the proportional term of the PID.
[Innn] where nnn is the integral term of the PID.
[Dnnn] where nnn is the derivative term of the PID.
Examples
M304 P10 I0.1 D300 sets bed PID to 10, 0.1, 300.
M500 Save to EEPROM
Saves variables to EEPROM (programmable read-only memory)
Parameters
M500
M501 Restore from EEPROM
Restores variable values previously stored in EEPROM.
Parameters
M501
M502 Reset EEPROM
Clears EEPROM and restores default values from the firmware.
Parameters
M502
M503 Report EEPROM Values
Outputs all variables and values stored in EEPROM.
Parameters
M503
M605 Independent Dual Extruder Control
Switches control mode for the independent dual extruders.
Parameters
M605 [Sx]
[Sx] where x is an index of 1 (dual extrusion mode) or 2 (duplication mode)
Examples
M605 S2 sets the printer to print in duplication mode.
M666 Endstop Calibration
Sets the offset between two endstops on the same movement axes to account for skew/squarness.
Parameters
M666 [Ynnn] [Znnn]
[Ynnn] where nnn is a value in mm representing the offset of the second Y endstop (right hand side) relative to to the first.
[Znnn] where nnn is a value in mm representing the offset of the second Z endstop (right hand side) relative to to the first.
Examples
M666 Z0.1 after the Z axis homes, the right hand side Z motor will lower by 0.1mm.
last updated: 7/31/18