Diff: Servo.cpp

Revision:

0:39cd1e782d1e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Servo.cpp	Mon Oct 18 13:17:22 2010 +0000
@@ -0,0 +1,74 @@
+/* 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();
+}