I use estlcam with an Arduino uno, but I did not use the shield. If you want to use the shield, get the real one from Protoneer. The cheap crappy Chinese version does not have the current grbl version pin out. It tried one once and it would overheat and shut down while having a household box fan blowing directly on the board. If you do attempt it, get real CNC mill drivers, not the cheap ones designed for 3D printers.
Also consider a real controller, like a https://docs.openbuilds.com/blackbox - the CNC shields are very bare, tiny little drivers barely enough for NEMA17s, and none of the other filtering, peripherals, outputs etc needed for a CNC
I started out with an Uno and dq542ma drivers (worked perfectly well) but now I'm using a Backbox with Estlcam and using the firmware flash as well, so basically a Blackbox NOT running grbl. Works great, yes have to be careful with the pinouts. Cheers Gary
I have the Uno with the DQ542MA drivers OpenBuilds used to sell on one machine and use Estlcam on that one. I went with the Backbox on my rotary because it costs about the same as buying a real Uno and quality drivers but the Blackbox, being plug and play, made the entire build so much easier. I wish it would have been around at the time of my first build.