Shorter paths to HAL, ExtUI (#17156)

Marlin/src/HAL/ESP32/Servo.h

@@ -0,0 +1,49 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 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/>.
+ *
+ */
+#pragma once
+
+#include <Arduino.h>
+
+class Servo {
+  static const int MIN_ANGLE =   0,
+                   MAX_ANGLE = 180,
+                   MIN_PULSE_WIDTH =  544,  // Shortest pulse sent to a servo
+                   MAX_PULSE_WIDTH = 2400,  // Longest pulse sent to a servo
+                   TAU_MSEC = 20,
+                   TAU_USEC = (TAU_MSEC * 1000),
+                   MAX_COMPARE = ((1 << 16) - 1), // 65535
+                   CHANNEL_MAX_NUM = 16;
+
+public:
+  Servo();
+  int8_t attach(const int pin);   // attach the given pin to the next free channel, set pinMode, return channel number (-1 on fail)
+  void detach();
+  void write(int degrees);        // set angle
+  void move(const int degrees);   // attach the servo, then move to value
+  int read();                     // returns current pulse width as an angle between 0 and 180 degrees
+
+private:
+  static int channel_next_free;
+  int channel;
+  int pin;
+  int degrees;
+};