Total rework of simulator for dev branch. Create separate thread for interrupt processes. Tick-accurate simulation of timers. Non-blocking character input for running in realtime mode. Decouple hardware sim from grbl code as much as possible. Expanded command line options. Provisions for cross-platform solution.

sim/kbhit.h

@@ -0,0 +1,39 @@
+/*
+  kbhit.h - keyboard hit detection - used in serial port replacement for grbl sim
+
+  linux kbhit taken from http://cboard.cprogramming.com/c-programming/63166-kbhit-linux.html. 
+  By 'thanatos':http://cboard.cprogramming.com/member.php?u=380
+
+  Part of Grbl Simulator
+
+  Copyright (c) 2014 Adam Shelly
+
+  Grbl is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Grbl is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+//if linux
+#include <stdio.h>
+#include <termios.h>
+#include <unistd.h>
+
+int  kbhit(void);
+void enable_kbhit(int);
+
+
+//else
+//#include <conio.h>
+//#define enable_kbhit(e) 
+//#define kbhit _kbhit
+//endif
+