Arduino vs BOB

[Larsson55]

I try to understand the difference between Arduino and a BOB (breakout board).On my CNC mill I bought a BOB which has all the input/output connections to run my CNC so could I have bought an Arduino instead and why?

And what is GRBL? If I understand from what I read on the web GRBL is some kind of programming for the Arduino. And what happens if I don't know to do any programming?

Thank you

[brucehoult]

Arduino is an IDE / code editing environment.

Arduino is a code library providing standardised simple access to typical microcontroller facilities on many different architectures.

Arduino is a manufacturer of microcontroller boards using a variety of different ISAs.

Based on a couple of minutes examination GRBL is plain C code, NOT written for the Arduino environment / library, but directly controlling the hardware specifically on AVR microcontrollers.

As such it should work on almost any board with one of the supported AVR chips, whether labelled "Arduino" or not. Conversely, there are many Arduino boards (official and 3rd party) that it will NOT work on.

[xvr]

GRBL is a RS274 (aka G code) interpreter and stepper motors controller that runs this G code on these steppers. This is 'heart' of CNC milling machine, 3D printers etc.
Written in C language and oriented to particular platform (however there are a ports of GRBL exist for other platforms, not only AVR)

[Ian.M]

Original GRBL and Gnea GRBL are highly optimised 3 axis + non-synchronous spindle CNC motion controller firmware to run on an ATmega328P MCU.  They are extremely closely coupled to the MCU architecture and are limited to all the pins of a particular function for all the axes being on a single port. Their development was frozen several years ago because the MCU was close to 100% utilised, so no new features were practical.   See https://all3dp.com/2/grbl-software-guide/ for an overview.

Their main successor is grblHAL  which needs a more powerful (usually 32 bit) MCU, but has a hardware abstraction layer so is relatively easy to port to a new MCU.  Other improvents include far more axes  (up to 8 on some MCUs), more G-code commands, macros and a whole bunch of other features.  See  https://github.com/grblHAL

If you run GRBL or grblHAL on an all-in-one CNC controller board you are limited to whatever stepper drivers, it either has on board or if it supports plug-in stepper driver modules, whatever you can get in the required form factor.  You will also be limited by the max. stepper and spindle supply voltages and currents it supports.   OTOH if you use an Arduino (or other suitable MCU board) plugged into a screw terminal breakout board, you get free choice of stepper and spindle drivers and their supply voltages, the downside being the cost of seperate modules for each and the space it takes to mount them all and wire them up.

[Larsson55]

I can't say now that I'm an expert on Arduino but at least I understand what it is and what it can do. I also understand what GRBL is. With my limited experience in electronics it's best to stick to a BOB when I need one. The reason I opened this thread is that I'm thinking to add a laser to my cnc and many sites offering lasers are talking about Arduino so there a lot to learn before I decide my next step..

My thanks to all for your time