Import grbl v1.1h
diff --git a/grbl/nuts_bolts.h b/grbl/nuts_bolts.h
new file mode 100644
index 0000000..c936f2b
--- /dev/null
+++ b/grbl/nuts_bolts.h
@@ -0,0 +1,87 @@
+/*
+ nuts_bolts.h - Header file for shared definitions, variables, and functions
+ Part of Grbl
+
+ Copyright (c) 2011-2016 Sungeun K. Jeon for Gnea Research LLC
+ Copyright (c) 2009-2011 Simen Svale Skogsrud
+
+ 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 nuts_bolts_h
+#define nuts_bolts_h
+
+#define false 0
+#define true 1
+
+#define SOME_LARGE_VALUE 1.0E+38
+
+// Axis array index values. Must start with 0 and be continuous.
+#define N_AXIS 3 // Number of axes
+#define X_AXIS 0 // Axis indexing value.
+#define Y_AXIS 1
+#define Z_AXIS 2
+// #define A_AXIS 3
+
+// CoreXY motor assignments. DO NOT ALTER.
+// NOTE: If the A and B motor axis bindings are changed, this effects the CoreXY equations.
+#ifdef COREXY
+ #define A_MOTOR X_AXIS // Must be X_AXIS
+ #define B_MOTOR Y_AXIS // Must be Y_AXIS
+#endif
+
+// Conversions
+#define MM_PER_INCH (25.40)
+#define INCH_PER_MM (0.0393701)
+#define TICKS_PER_MICROSECOND (F_CPU/1000000)
+
+#define DELAY_MODE_DWELL 0
+#define DELAY_MODE_SYS_SUSPEND 1
+
+// Useful macros
+#define clear_vector(a) memset(a, 0, sizeof(a))
+#define clear_vector_float(a) memset(a, 0.0, sizeof(float)*N_AXIS)
+// #define clear_vector_long(a) memset(a, 0.0, sizeof(long)*N_AXIS)
+#define max(a,b) (((a) > (b)) ? (a) : (b))
+#define min(a,b) (((a) < (b)) ? (a) : (b))
+#define isequal_position_vector(a,b) !(memcmp(a, b, sizeof(float)*N_AXIS))
+
+// Bit field and masking macros
+#define bit(n) (1 << n)
+#define bit_true(x,mask) (x) |= (mask)
+#define bit_false(x,mask) (x) &= ~(mask)
+#define bit_istrue(x,mask) ((x & mask) != 0)
+#define bit_isfalse(x,mask) ((x & mask) == 0)
+
+// Read a floating point value from a string. Line points to the input buffer, char_counter
+// is the indexer pointing to the current character of the line, while float_ptr is
+// a pointer to the result variable. Returns true when it succeeds
+uint8_t read_float(char *line, uint8_t *char_counter, float *float_ptr);
+
+// Non-blocking delay function used for general operation and suspend features.
+void delay_sec(float seconds, uint8_t mode);
+
+// Delays variable-defined milliseconds. Compiler compatibility fix for _delay_ms().
+void delay_ms(uint16_t ms);
+
+// Delays variable-defined microseconds. Compiler compatibility fix for _delay_us().
+void delay_us(uint32_t us);
+
+// Computes hypotenuse, avoiding avr-gcc's bloated version and the extra error checking.
+float hypot_f(float x, float y);
+
+float convert_delta_vector_to_unit_vector(float *vector);
+float limit_value_by_axis_maximum(float *max_value, float *unit_vec);
+
+#endif