SO3 - Updated to 409, now problems

SO3, upgraded to 409, get an error when trying to connect to the SO3. Try to connect again and get a “Port already open” error and CM crashes.

Ticket submitted to .

I’ve read others brick their machines so I’m not touching anything until I hear back.

Could I use any other CAM software to make the SO3 work, or must I use CM?

Halp me, Obi Shapokenbi. You’re my only hope.

You can use pretty much anything to communicate with Grbl — the issue is that 1.1 uses different responses than Grbl 0.9 and before, so communication / control programs have to be updated to accept that.

List of them here:

Forgive me if I’m being super obvious, but in addition to updating to CM4.09 did you also reflash your board with Grbl 1.1, or is it still running the old Grbl 0.9? If so, please disregard, if not check here:


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I just followed the link on the website to download and install 409, I didn’t see anything about flashing the board. So I’m assuming it didn’t flash?

Forgot to add, when installing 409 I did see a warning about grbl 1.1, that I can’t go back, something, something.

You can go back.

See the first two (visible) posts in:

Ok, so it seems that I did flash and need to undo it.

For what it’s worth, I don’t recall seeing that long post with all the warnings, and being so used to the frequent “click here to update” habit, I assumed it would just be another update. Yes, I am responsible for my gear and knowing what I’m getting into and should read the fine print. I’m a novice and will learn from this. Maybe a clearer warning on the “beta” status of products, and if they are optional or not.

I do appreciate the hard work from the team on chasing problems.

Flashing Grbl 1.1 and installing Carbide Motion 4.09 are two different processes, but both need to completed in unison to have it all work. Carbide Motion is the software on your PC/Mac and Grbl is the software on your controller card. Carbide Motion 3 works with Grbl 0.9, Carbide Motion 4 onwards works with Grbl 1.1. Following the link I posted above will guide you through the whole process.

Also as Will stated you can go back to CM3 Grbl 0.9 if need be, I’ve done it several times now. Just a very little bit trickier than going forward to 1.1 and CM4.


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