A class to control a model R/C servo, using a PwmOut
Servo.cpp
- Committer:
- b28nguye
- Date:
- 2019-09-27
- Revision:
- 4:22b2abaa0f44
- Parent:
- 2:8995c167f399
File content as of revision 4:22b2abaa0f44:
/* mbed R/C Servo Library * * Copyright (c) 2007-2010 sford, cstyles * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "Servo.h" #include "mbed.h" static float clamp(float value, float min, float max) { if(value < min) { return min; } else if(value > max) { return max; } else { return value; } } Servo::Servo(PinName pin) : _pwm(pin) { calibrate(); write(0.5); } void Servo::write(float percent) { float offset = _range * 2.0 * (percent - 0.5); _pwm.pulsewidth(0.0015 + clamp(offset, -_range, _range)); _p = clamp(percent, 0.0, 1.0); } void Servo::position(float degrees) { float offset = _range * (degrees / _degrees); _pwm.pulsewidth(0.0015 + clamp(offset, -_range, _range)); } void Servo::calibrate(float range, float degrees) { _range = range; _degrees = degrees; } float Servo::read() { return _p; } Servo& Servo::operator= (float percent) { write(percent); return *this; } Servo& Servo::operator= (Servo& rhs) { write(rhs.read()); return *this; } Servo::operator float() { return read(); }