Initial commit

Using TMC2208 in standalone mode, I've inverted the stepper direction to match Anycubics pin layout. M110 memory watcher was removed due to redundancy and - ironically - to save memory.

buildroot/bin/opt_set_adv

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+SED=$(which gsed || which sed)
+
+eval "${SED} -i 's/\(#define \b${1}\b\).*$/\1 ${2}/g' Marlin/Configuration_adv.h"