A class to control a model R/C servo, using a PwmOut
Servo.cpp
- Committer:
- simon
- Date:
- 2009-11-16
- Revision:
- 0:24148c673250
- Child:
- 2:8995c167f399
File content as of revision 0:24148c673250:
/* mbed R/C Servo * Copyright (c) 2007-2009 sford, cstyles * Released under the MIT License: http://mbed.org/license/mit */ #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(); }