CNC3018 Woodpecker Grbl Firmware Notes

The Woodpecker boards shares the USB 5VDC line with the power input. I use a non-powered USB hub between my computer and the CNC machine. Honestly I'm not sure if it actually does anything to isolate or perhaps I'm just lucky. (probably the latter) TODO: find and buy a good isolated USB, such as the Adafruit USB Isolator - 100mA Isolated Low/Full Speed USB.

For reference, my current firmware version is Grbl 1.1f, or more specifically $I result:

[VER:1.1f.20170801:]
[OPT:V,15,128]

The Woodpecker board has a CH340 serial chip and is accessible via the usual putty 8N1/115200:

"Help" $$ is simply this one line:

[HLP:$$ $# $G $I $N $x=val $Nx=line $J=line $SLP $C $X $H ~ ! ? ctrl-x]

That's not very helpful, but according to the documentation, newer versions will apparently provide more details:

$$ (view Grbl settings)
$# (view # parameters)
$G (view parser state)
$I (view build info)
$N (view startup blocks)
$x=value (save Grbl setting)
$Nx=line (save startup block)
$C (check gcode mode)
$X (kill alarm lock)
$H (run homing cycle)
~ (cycle start)
! (feed hold)
? (current status)
ctrl-x (reset Grbl)

My settings via $$ (always a good idea to save these BEFORE upgrading firmware):

$0=10                                                           
$1=25
$2=0
$3=5
$4=0
$5=0
$6=0
$10=1
$11=0.010
$12=0.002
$13=0
$20=0
$21=0
$22=0
$23=0
$24=25.000
$25=500.000
$26=250
$27=1.000
$30=1000
$31=0
$32=0
$100=800.000
$101=800.000
$102=800.000
$110=800.000
$111=800.000
$112=600.000
$120=10.000
$121=10.000
$122=10.000
$130=200.000
$131=200.000
$132=200.000

The Grbl Default Settings:

$0=10 (step pulse, usec)                                          
$1=25 (step idle delay, msec)
$2=0 (step port invert mask:00000000)
$3=6 (dir port invert mask:00000110)
$4=0 (step enable invert, bool)
$5=0 (limit pins invert, bool)
$6=0 (probe pin invert, bool)
$10=3 (status report mask:00000011)
$11=0.020 (junction deviation, mm)
$12=0.002 (arc tolerance, mm)
$13=0 (report inches, bool)
$20=0 (soft limits, bool)
$21=0 (hard limits, bool)
$22=0 (homing cycle, bool)
$23=1 (homing dir invert mask:00000001)
$24=50.000 (homing feed, mm/min)
$25=635.000 (homing seek, mm/min)
$26=250 (homing debounce, msec)
$27=1.000 (homing pull-off, mm)
$100=314.961 (x, step/mm)
$101=314.961 (y, step/mm)
$102=314.961 (z, step/mm)
$110=635.000 (x max rate, mm/min)
$111=635.000 (y max rate, mm/min)
$112=635.000 (z max rate, mm/min)
$120=50.000 (x accel, mm/sec^2)
$121=50.000 (y accel, mm/sec^2)
$122=50.000 (z accel, mm/sec^2)
$130=225.000 (x max travel, mm)
$131=125.000 (y max travel, mm)
$132=170.000 (z max travel, mm)

See also the settings reported by Brandon2255p

My $# result:

[G54:0.000,0.000,0.000]                                          
[G55:0.000,0.000,0.000]
[G56:0.000,0.000,0.000]
[G57:0.000,0.000,0.000]
[G58:0.000,0.000,0.000]
[G59:0.000,0.000,0.000]
[G28:0.000,0.000,0.000]
[G30:0.000,0.000,0.000]
[G92:0.000,0.000,0.000]
[TLO:0.000]
[PRB:0.000,0.000,0.000:0]

Whistling sound? Thanks chamnit:

The PWM frequency changed from 7.8 kHz to 1kHz in Grbl v1.1. To change back, edit the cpu_map.h file and look for the SPINDLE_TCCRB_INIT_MASK macros. There are several commented, including the one for 1kHz. Just swap them and recompile

If for some reason I ever need to replace the controller board, I'll probably try the SAINSMART Controller Board for Genmtisu CNC Router 3018, 3018-PRO, 1810-RP and the Offline Controller Module (although need to determine if there's anything hardware specific to their Genmtisu)

Resources, Inspiration, Credits, and Other Links:

• Beware of upgrade mishaps: gnea/grbl/issues/336
  
  
• gnea/grbl/releases on GitHub 
  
  
• Flashing Grbl to an Arduino
  
  
• Better Grbl Support: octoprint plugin "Provides core functionality and UI integration for GRBL based engravers and CNC machines"
  
  
•  mic159/octoprint-grbl-plugin
  
  
• OpenBuilds - controller board forum
  
  
• my Visual Studio Extension for G-Code syntax highlighting (not VS Code)