Servo & PWM support for LPC1768 (#7500)

Marlin/src/HAL/HAL_LPC1768/LPC1768_Servo.h

@@ -0,0 +1,69 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2017 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program 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.
+ *
+ * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * The class Servo uses the PWM class to implement it's functions
+ *
+ * The PWM1 module is only used to generate interrups at specified times. It
+ * is NOT used to directly toggle pins. The ISR writes to the pin assigned to
+ * that interrupt
+ *
+ * All PWMs use the same repetition rate - 20mS because that's the normal servo rate
+ *
+ */
+
+#ifndef LPC1768_SERVO_h
+  #define LPC1768_SERVO_h
+
+  #ifdef TARGET_LPC1768
+    #include <inttypes.h>
+
+
+    class Servo {
+      public:
+        Servo();
+        int8_t attach(int pin);            // attach the given pin to the next free channel, set pinMode, return channel number (-1 on fail)
+        int8_t attach(int pin, int min, int max); // as above but also sets min and max values for writes.
+        void detach();
+        void write(int value);             // if value is < 200 it is treated as an angle, otherwise as pulse width in microseconds
+        void writeMicroseconds(int value); // write pulse width in microseconds
+        void move(int value);              // attach the servo, then move to value
+                                           // if value is < 200 it is treated as an angle, otherwise as pulse width in microseconds
+                                           // if DEACTIVATE_SERVOS_AFTER_MOVE wait SERVO_DELAY, then detach
+        int read();                        // returns current pulse width as an angle between 0 and 180 degrees
+        int readMicroseconds();            // returns current pulse width in microseconds for this servo (was read_us() in first release)
+        bool attached();                   // return true if this servo is attached, otherwise false
+
+      private:
+        uint8_t servoIndex;               // index into the channel data for this servo
+        int min;
+        int max;
+    };
+
+
+    #define HAL_SERVO_LIB Servo
+
+  #endif
+#endif
+
+
+