--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/motion_control.h	Sat Nov 07 13:23:07 2015 +0100
@@ -0,0 +1,32 @@
+/*
+  motion_control.h - high level interface for issuing motion commands
+  Part of Grbl
+
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
+  Copyright (c) 2011 Sungeun K. Jeon
+  
+  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/>.
+*/
+
+#ifndef motion_control_h
+#define motion_control_h
+
+// Execute an arc in offset mode format. position == current xyz, target == target xyz, 
+// offset == offset from current xyz, axis_XXX defines circle plane in tool space, axis_linear is
+// the direction of helical travel, radius == circle radius, isclockwise boolean. Used
+// for vector transformation direction.
+void mc_arc(float *position, float *target, float *offset, unsigned char axis_0, unsigned char axis_1,
+  unsigned char axis_linear, float feed_rate, float radius, unsigned char isclockwise, uint8_t extruder);
+  
+#endif