- GRBL Breakout Shield
GRBL Breakout Shield
3DTek.xyz's 'GRBL Breakout Shield'
To the extent possible under law, 3DTek.xyz has waived all copyright and related or neighbouring rights to GRBL Breakout Shield. This work is published from: Australia.
With the well know G-shield only having 3 drivers, a breakout shield is needed to allow 4 motors to each have their own driver, as well as to provide convenient connection to all the peripheral controls.
The CNC Shield from protoneer was doing the trick until GRBL V.9 changed some pinouts. It also didn't have Limit switch filters, used pin headers for all connections, and has gone closed source - all things which are inconvenient and so...3DTek.xyz have made and released to public domain the 'GRBL Breakout Shield'
We hope that alibaba merchants will jump into action with these Gerber Files and flood out very cheap pre populated boards so we don't have to make them ourselves!
How It works:
It sits atop and Arduino uno (or clone) running GRBL and takes care of breaking out all the pins required for your machine peripheral controls (Estop, Feed hold, limit switches...etc)
Your 4 DRV8825 or A4988 based drivers sit on the GRBL Breakout Shield.
3 x 0.47 uf caps filter the limit switch lines to prevent all the limit switch false trigger issues which plague G-shield and CNC setups and there are through holes for a 20 or 40mm fan to be placed on standoffs to sit up above and cool the drivers.
Not below the positions of the blue jumpers, these are the standard settings for most CNC's using GRBL.
Wire up the steppers wires to the shields motor outputs not concerning with left to right or right to left - so long as when looking from either way you can see the wires are in this colour order.
Limit Switch Connections
GRBL Defaults to Normally Open as per the diagram on the right below (for some unknown reason) however can be set to operate normally closed (if wired as per diagram on left) by changing GRBL parameter $5 =1.
Omron Lever Switch Pinout
Common is our GND NC is Normally Closed and NO normally open
GRBL Breakout Shield has been tested to work well with both DRV8825 and A4988 based stepper drivers.
GRBL Breakout Shield is Public Domain, not licensed, no rights are reserved. Other than the GRBR files, other links in this page forward to projects and systems which may have rights reserved.