feat: Add option "nom6" to avoid emitting M6 on tool changes.

[olawlor]

When combined with the existing "nog64" and "nog81", this allows GRBL
to cut the resulting gcode successfully.

[eyal0]

MY is the tool change code, right? How can removing M6 help you?

[olawlor]

Currently, pcb2gcode emits an M6 gcode before cutting traces or drilling holes. The common no frills open-source GRBL firmware doesn't support M6 at all (issuing it literally locks up the firmware), but you do the tool changes by hand anyway, and there's an M0 (pause) right afterwards, so you can still change the cutter if the M6 is not there.

GRBL is the factory firmware on many entry-level CNC routers, including 3018 machines that are ideal for PCB milling. This change seems cleaner than manually removing M6 calls after running pcb2gcode.

[eyal0]

I also used a CNC with grbl installed. The bCNC that I ran on Linux was giving instructions to grbl and it intercepted the M6 and did a routine to change bits. I would hope that your software can also do that but maybe it cannot?

What is the program that you are using to send commands to GRBL?

[olawlor]

I've been using either Universal G-Code Sender ( https://github.com/winder/Universal-G-Code-Sender ) or Pronterface, both of which pass pcb2gcode's M6 through unmodified, locking up GRBL. (bCNC looks neat, I like the probe features, though it doesn't seem to understand GRBL $H homing.)

…

On Wed, Mar 2, 2022 at 12:38 PM Eyal ***@***.***> wrote: I also used a CNC with grbl installed. The bCNC that I ran on Linux was giving instructions to grbl and it intercepted the M6 and did a routine to change bits. I would hope that your software can also do that but maybe it cannot? What is the program that you are using to send commands to GRBL? — Reply to this email directly, view it on GitHub <#620 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAN6NURIFMCZY6VN2XV2VODU57NWLANCNFSM5PNT7TMQ> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you authored the thread.Message ID: ***@***.***>

-- Dr. Orion Sky Lawlor ***@***.*** http://www.cs.uaf.edu/~olawlor/

[coveralls]

Coverage remained the same at 69.259% when pulling b5e4705 on olawlor:master into 14e0f17 on pcb2gcode:master.