marlin/Marlin/src/HAL/STM32F1/Servo.h

/**
 * 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
 * Copyright (c) 2017 Victor Perez
 *
 * 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 <https://www.gnu.org/licenses/>.
 *
 */
#pragma once

// Pin number of unattached pins
#define NOT_ATTACHED                    (-1)
#define INVALID_SERVO                   255

#ifndef MAX_SERVOS
  #define MAX_SERVOS 3
#endif

#define SERVO_DEFAULT_MIN_PW            544
#define SERVO_DEFAULT_MAX_PW            2400
#define SERVO_DEFAULT_MIN_ANGLE         0
#define SERVO_DEFAULT_MAX_ANGLE         180

#define HAL_SERVO_LIB libServo

class libServo {
  public:
    libServo();
    bool attach(const int32_t pin, const int32_t minAngle=SERVO_DEFAULT_MIN_ANGLE, const int32_t maxAngle=SERVO_DEFAULT_MAX_ANGLE);
    bool attached() const { return pin != NOT_ATTACHED; }
    bool detach();
    void move(const int32_t value);
    int32_t read() const;
  private:
    void servoWrite(uint8_t pin, const uint16_t duty_cycle);

    uint8_t servoIndex;               // index into the channel data for this servo
    int32_t pin = NOT_ATTACHED;
    int32_t minAngle;
    int32_t maxAngle;
    int32_t angle;

    bool setupSoftPWM(const int32_t pin);
    void pauseSoftPWM();
    void pwmSetDuty(const uint16_t duty_cycle);
};