/* Copyright (c) 2017 John K. Bennett. All right reserved. ESP32_Servo.h - Servo library for ESP32 - Version 1 Original Servo.h written by Michael Margolis in 2009 This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ /* A servo is activated by creating an instance of the Servo class, and passing the desired GPIO pin to the attach() method. The servos are pulsed in the background using the value most recently written using the write() method. The class methods are: Servo - Class for manipulating servo motors connected to ESP32 pins. int attach(pin ) - Attaches the given GPIO pin to the next free channel (channels that have previously been detached are used first), returns channel number or 0 if failure. All pin numbers are allowed, but only pins 2,4,12-19,21-23,25-27,32-33 are recommended. int attach(pin, min, max ) - Attaches to a pin setting min and max values in microseconds; enforced minimum min is 500, enforced max is 2500. Other semantics same as attach(). void write () - Sets the servo angle in degrees; a value below 500 is treated as a value in degrees (0 to 180). These limit are enforced, i.e., values are treated as follows: Value Becomes ----- ------- < 0 0 0 - 180 value (treated as degrees) 181 - 499 180 500 - (min-1) min min-max (from attach or default) value (treated as microseconds) (max+1) - 2500 max void writeMicroseconds() - Sets the servo pulse width in microseconds. min and max are enforced (see above). int read() - Gets the last written servo pulse width as an angle between 0 and 180. int readMicroseconds() - Gets the last written servo pulse width in microseconds. bool attached() - Returns true if this servo instance is attached. void detach() - Stops an the attached servo, frees its attached pin, and frees its channel for reuse). *** ESP32-specific functions ** setTimerWidth(value) - Sets the PWM timer width (must be 16-20) (ESP32 ONLY); as a side effect, the pulse width is recomputed. int readTimerWidth() - Gets the PWM timer width (ESP32 ONLY) */ #ifndef ESP32_Servo_h #define ESP32_Servo_h // Values for TowerPro MG995 large servos (and many other hobbyist servos) #define DEFAULT_uS_LOW 1000 // 1000us #define DEFAULT_uS_HIGH 2000 // 2000us // Values for TowerPro SG90 small servos //#define DEFAULT_uS_LOW 400 //#define DEFAULT_uS_HIGH 2400 #define DEFAULT_TIMER_WIDTH 16 #define DEFAULT_TIMER_WIDTH_TICKS 65536 #define ESP32_Servo_VERSION 1 // software version of this library #define MIN_PULSE_WIDTH 500 // the shortest pulse sent to a servo #define MAX_PULSE_WIDTH 2500 // the longest pulse sent to a servo #define DEFAULT_PULSE_WIDTH 1500 // default pulse width when servo is attached #define DEFAULT_PULSE_WIDTH_TICKS 4825 #define REFRESH_CPS 50 #define REFRESH_USEC 20000 #define MAX_SERVOS 16 // no. of PWM channels in ESP32 /* * This group/channel/timmer mapping is for information only; * the details are handled by lower-level code * * LEDC Chan to Group/Channel/Timer Mapping ** ledc: 0 => Group: 0, Channel: 0, Timer: 0 ** ledc: 1 => Group: 0, Channel: 1, Timer: 0 ** ledc: 2 => Group: 0, Channel: 2, Timer: 1 ** ledc: 3 => Group: 0, Channel: 3, Timer: 1 ** ledc: 4 => Group: 0, Channel: 4, Timer: 2 ** ledc: 5 => Group: 0, Channel: 5, Timer: 2 ** ledc: 6 => Group: 0, Channel: 6, Timer: 3 ** ledc: 7 => Group: 0, Channel: 7, Timer: 3 ** ledc: 8 => Group: 1, Channel: 0, Timer: 0 ** ledc: 9 => Group: 1, Channel: 1, Timer: 0 ** ledc: 10 => Group: 1, Channel: 2, Timer: 1 ** ledc: 11 => Group: 1, Channel: 3, Timer: 1 ** ledc: 12 => Group: 1, Channel: 4, Timer: 2 ** ledc: 13 => Group: 1, Channel: 5, Timer: 2 ** ledc: 14 => Group: 1, Channel: 6, Timer: 3 ** ledc: 15 => Group: 1, Channel: 7, Timer: 3 */ class Servo { public: Servo(); // Arduino Servo Library calls int attach(int pin); // attach the given pin to the next free channel, returns channel number or 0 if failure int 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 < MIN_PULSE_WIDTH its treated as an angle, otherwise as pulse width in microseconds void writeMicroseconds(int value); // Write pulse width in microseconds 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 bool attached(); // return true if this servo is attached, otherwise false // ESP32 only functions void setTimerWidth(int value); // set the PWM timer width (ESP32 ONLY) int readTimerWidth(); // get the PWM timer width (ESP32 ONLY) private: int usToTicks(int usec); int ticksToUs(int ticks); static int ServoCount; // the total number of attached servos static int ChannelUsed[]; // used to track whether a channel is in service int servoChannel = 0; // channel number for this servo int min = DEFAULT_uS_LOW; // minimum pulse width for this servo int max = DEFAULT_uS_HIGH; // maximum pulse width for this servo int pinNumber = 0; // GPIO pin assigned to this channel int timer_width = DEFAULT_TIMER_WIDTH; // ESP32 allows variable width PWM timers int ticks = DEFAULT_PULSE_WIDTH_TICKS; // current pulse width on this channel int timer_width_ticks = DEFAULT_TIMER_WIDTH_TICKS; // no. of ticks at rollover; varies with width }; #endif