I've set up an Arduino Uno some time ago with an older release of grbl just to poke around and see what all the fuss was about. Here is what I learned and saw at that time:
The pulse trains and ultimately the motion itself appeared to be adequate for a small machine.
I/O was limited to the very basic and typical needs, again, well suited for a small machine.
Available GUI's were equally targeted towards simple environments.
Installation of many of the GUI's were unnecessarily difficult.
Decent documentation... sometimes any documentation at all was non-existent.
User "ergonomics" of the necessary windows, tabs and buttons was for the most part pathetic.
I had some time to play around the last few days and thought I would look into whether the GUI world for grbl has advanced to the point where anyone familiar with other popular hobby cnc controls could use or understand them. Just to be clear, I would be basing my judgements on what I have already seen and experienced in hobby controls like that of Flashcut, Mach, LinuxCNC, Eding, DeskCNC, Etc. These are all programs that the majority of users could walk up to and semi understand what they were looking at, and obtain results they expected.
My first step was to seek out what was out there, then download them all. Before installing, I went back and reviewed their related web pages to see if I wanted to bother installing them, based on the fact that I wanted to specifically look at how they would apply to a simple 3 axis router or mill. I loaded grbl 1.1 on a new Nano and connected it to some drivers and motors I had laying around. In no particular order, I so far have either played with or attempted to play with the following:
UGS - Rather useless for anything more than just sending it seems. I was able to home the system, set zero's etc and run some g-code. I never could learn much from the "dro's" as they never reflected anything that made sense location wise, but at least I knew grbl was installed and my limit and I/O switches were working as well as my outputs. I need to come back to it to see if I can find the thrill others must have.
Denvi/Candle Interface - Easily connected, probably one of the best looking screens I have come across. Ergonomic and visually makes sense. Has a stunning display of the tool path that updates tool position while the machine is running. I have not seen anything like this in any others I have tried so far. This would be my hands down favorite if it were not for a few things I can not get my head around. For one, when you jog in the X+, Y+ direction, the DRO's go negative ! (Z- goes Positive). Now one would think there is a reason for this AND a SETTING to adjust it, but I can not find anything. This alone almost makes me think the program is not useable for a small mill. Another thing is that jog "step" adjustments appear to actually be " motor steps" and not actual dimensions (I have to stop long enough to fully analyze though). In other words, if you set the step to "1", one would think it would move 1 INCH. But that is not the case. Sadly, it looks like the program has not been updated for a year which is a real source of agony as THIS IS THE ONE I GRAVITATE TO the most so far. Crisp, clean, multiple tool path views, zoom, pan, Iso, etc. WHERE IS THIS DEVELOPER ? They should finish this one !
109JB's Interface - Very simple appearance, but could not explore it because it would just crash when I would attempt to connect to the Nano I set up with grbl 1.1.
bCNC Interface - I've never been a big fan of the "windows ribbon" look, but I could see that the screen looked to reasonably separate the 'geek junk' from the machining stuff most of us actually care about. Sure, seeing the verbose communication with the arduino is handy for troubleshooting, and I am glad bCnc does not burden the user with it on the main machine control screen. It installed easily on my Linux Mint laptop, but unfortunately, I could not for the life of me figure out what PORT I was supposed to use to connect with. I thought it might be a simple matter to install bCnc on a windows laptop where the PORT might be more obvious... But a windows install is rather painful, so I did not test it yet. Why do things need to be this difficult ?
source rabbit interface - on Windows - super easy connection, understandable window, dro's that updated, decent window for very basic operation. But, I did not see an easy way to make it RETAIN that I wanted inches as a default thru out and while it has a "visualization" of the tool path, you only pop up an image of what the path looks like and no actual tool indicator following any path. It was very basic, better I thought than UGS, but certainly not enough to make an old hobby control user happy.
grbl panel interface - easily connected, looked to be quite useable as a hobby router or mill control. Setting Machine zero as well as program zero made sense once you understood what to do (note that I edited the HOMING_FORCE_SET_OPTION so that homing set machine zero at zero and not some freaky negative meaningless drivel). What I did not like is that the verbose communication with the board is on the main page (users running a machine dont care!) and there are buttons on screen that should say things that makes sense. Instead of saying "go to specl Posn1", users should be able to label the button with things that they are familiar with like "go to machine zero" or "go to program zero". Some buttons should have a second chance... unfortunately, if you hit the home button, its going to home...... if you hit the zero button... it immediately zeros... no confirmation that you may have accidentally hit the button.
grblgru - Awful busy display... the many colors scares me into that kiddie crayon look of default Mach3. While I can connect, I could not yet fully explore this gui simply because it seems to lock up after the first jog move. The verbose communication shows continued communication, but the Nano does not send any pulses to the drivers. Not sure what is up with that.
chilipepper - I did have it connected on a windows installation, but it sure is not plain and simple as to how and where... So much so, that when I returned to it a second time, I had no clue how to get the connection actually made this second time. Sure.. there were "messages" telling me I was not connected, and to "simply pull down the connection from the 'menu'"... WHAT MENU ? WHERE MENU ?.... Oh, I will return to look at it, but frankly, the whole web based/but uses all web libraries leaves me less than tickled. I would never recommend it for anyone with priority or secure prototype work because there is no good way to really be secure in any SaaS environment with people you do not even know running it.
tgFX interface - looked promising... but they bailed and pushed for chilipepper.
Well, thats what I saw so far. I have more to explore, but I think what is left are ones that did not make an impression on me at their webpage or github page.
But, Candle.... that is my favorite so far for ergonomics and layout, but it looks dead. Anyone with other grbl gui opinions out there ?