A class to control a model R/C servo, using a PwmOut
Diff: Servo.cpp
- Revision:
- 0:24148c673250
- Child:
- 2:8995c167f399
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Servo.cpp Mon Nov 16 18:24:16 2009 +0000 @@ -0,0 +1,56 @@ +/* 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(); +}