Diff: PwmOut.h

Revision:

0:a8fa94490a0a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PwmOut.h	Sat Sep 22 10:32:07 2012 +0000
@@ -0,0 +1,148 @@
+/* mbed Microcontroller Library - PwmOut
+ * Copyright (c) 2007-2011 ARM Limited. All rights reserved.
+ */ 
+ 
+#ifndef MBED_PWMOUT_H
+#define MBED_PWMOUT_H
+
+#include "device.h"
+
+#if DEVICE_PWMOUT
+
+#include "platform.h"
+#include "PinNames.h"
+#include "PeripheralNames.h"
+#include "Base.h"
+
+namespace mbed {
+
+/* Class: PwmOut
+ *  A pulse-width modulation digital output
+ *
+ * Example
+ * > // Fade a led on.
+ * > #include "mbed.h"
+ * >
+ * > PwmOut led(LED1);
+ * > 
+ * > int main() {
+ * >     while(1) {
+ * >         led = led + 0.01;
+ * >         wait(0.2);
+ * >         if(led == 1.0) {
+ * >             led = 0;
+ * >         }
+ * >     }
+ * > }
+ *
+ *  Note that on the LPC1768 and LPC2368, the PWMs all share the same
+ *  period - if you change the period for one, you change it for all.
+ *  Although routines that change the period maintain the duty cycle
+ *  for its PWM, all other PWMs will require their duty cycle to be
+ *  refreshed.
+ */
+class PwmOut : public Base {
+
+public:
+
+    /* Constructor: PwmOut
+     *  Create a PwmOut connected to the specified pin
+     *
+     * Variables:
+     *  pin - PwmOut pin to connect to
+     */
+    PwmOut(PinName pin, const char *name = NULL);
+
+    /* Function: write
+     *  Set the ouput duty-cycle, specified as a percentage (float)
+     *
+     * Variables:
+     *  value - A floating-point value representing the output duty-cycle, 
+     *    specified as a percentage. The value should lie between
+     *    0.0f (representing on 0%) and 1.0f (representing on 100%).
+     *    Values outside this range will be saturated to 0.0f or 1.0f.	 
+     */
+    void write(float value);
+
+    /* Function: read
+     *  Return the current output duty-cycle setting, measured as a percentage (float)
+     *
+     * Variables:
+     *  returns - A floating-point value representing the current duty-cycle being output on the pin, 
+     *    measured as a percentage. The returned value will lie between
+     *    0.0f (representing on 0%) and 1.0f (representing on 100%).
+     *
+     * Note:
+     *  This value may not match exactly the value set by a previous <write>.
+     */
+    float read();
+    
+    /* Function: period
+     *  Set the PWM period, specified in seconds (float), keeping the
+     *  duty cycle the same.
+     *
+     *  Note:
+     *   The resolution is currently in microseconds; periods smaller than this
+     *   will be set to zero.
+     */
+    void period(float seconds);
+
+    /* Function: period_ms
+     *  Set the PWM period, specified in milli-seconds (int), keeping the
+     *  duty cycle the same.
+     */
+    void period_ms(int ms);
+
+    /* Function: period_us
+     *  Set the PWM period, specified in micro-seconds (int), keeping the
+     *  duty cycle the same.
+     */
+    void period_us(int us);
+
+    /* Function: pulsewidth
+     *  Set the PWM pulsewidth, specified in seconds (float), keeping the
+     *  period the same.
+     */
+    void pulsewidth(float seconds);
+
+    /* Function: pulsewidth_ms
+     *  Set the PWM pulsewidth, specified in milli-seconds (int), keeping
+     *  the period the same.
+     */
+    void pulsewidth_ms(int ms);
+
+    /* Function: pulsewidth_us
+     *  Set the PWM pulsewidth, specified in micro-seconds (int), keeping
+     *  the period the same.
+     */
+    void pulsewidth_us(int us);
+
+#ifdef MBED_OPERATORS
+    /* Function: operator=
+     *  A operator shorthand for <write()>
+     */
+    PwmOut& operator= (float value);
+    PwmOut& operator= (PwmOut& rhs);
+
+    /* Function: operator float()
+     *  An operator shorthand for <read()>
+     */
+    operator float();
+#endif
+
+#ifdef MBED_RPC
+    virtual const struct rpc_method *get_rpc_methods();
+    static struct rpc_class *get_rpc_class();
+#endif
+
+protected:
+
+    PWMName _pwm;
+
+};
+
+} // namespace mbed
+
+#endif
+
+#endif