GRBL Upgrade via avrdude

Hi Folks,

For those interested, this is how I upgraded from GRBL version 1.1f to 1.1h. I am not sure there is any real need to do this, but the machine can always be flashed back to normal with the Carbide software or with the process I used.

You could use this process to add your own functionality to GRBL if you wish, but that’s another thing entirely.

I was able to backup my existing GRBL 1.1f firmware and then flash GRBL 1.1h on my Shapeoko 4.

This guy did it for his 3018 Pro CNC but the process is the same. You have to install avrdude but that is part of the Arduino IDE and should be available for all platforms. I use Linux and I ran it from a terminal.

Update GRBL firmware on CNC 3018 Pro · One Transistor

Be sure to do the backup first! Also, make a note of all of your settings with the $$ command in the GRBL console. I saved those settings to a text file.

Going from 1.1f to 1.1h, my settings did not change, but your situation may be different! You can reenter them if they change.

I used the pre-compiled GRBL 1.1h .hex file found on the GitHub page:

The only thing that threw me for a loop was having to hold / activate the Z limit switch on the Shapeoko 4. I was able to slip a metal nail in the gap by my Z limit switch as it triggers with metal. I suppose those with other types of limit switches would have to hold the triggers some other way.

Like I said, I’m not sure how much different things are with version 1.1h, but it has been the latest version since 2019, so I think it is fairly stable at this point. Perhaps there have been some bug fixes.

I did this upgrade with my 3018 last year and I didn’t notice a thing. :slight_smile:


I think the only time EEPROM will be overwritten is if you’re upgrading from 0.9 or earlier. That version was early SO3 days.

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