Beep using PWM and speaker

Dependents:   Hangman Weather_Station Ultrasonic Ultrasonicdistancesensor ... more

Files at this revision

API Documentation at this revision

Comitter:
pprasad7
Date:
Thu Oct 11 20:14:49 2012 +0000
Commit message:
beep;

Changed in this revision

beep.cpp Show annotated file Show diff for this revision Revisions of this file
beep.h Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r 080ef5594cce beep.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/beep.cpp	Thu Oct 11 20:14:49 2012 +0000
@@ -0,0 +1,56 @@
+#include "beep.h"
+#include "mbed.h"
+
+/** class to make sound with a buzzer, based on a PwmOut
+ *   The class use a timeout to switch off the sound  - it is not blocking while making noise
+ *
+ * Example:
+ * @code
+ * // Beep with 1Khz for 0.5 seconds
+ * #include "mbed.h"
+ * #include "beep.h"
+ * 
+ * Beep buzzer(p21);
+ * 
+ * int main() {
+ *       ...
+ *   buzzer.beep(1000,0.5);    
+ *       ...
+ * }
+ * @endcode
+ */
+
+using namespace mbed;
+ // constructor
+ /** Create a Beep object connected to the specified PwmOut pin
+  *
+  * @param pin PwmOut pin to connect to 
+  */
+    
+Beep::Beep(PinName pin) : _pwm(pin) {
+    _pwm.write(0.0);     // after creating it have to be off
+}
+
+ /** stop the beep instantaneous 
+  * usually not used 
+  */
+void Beep::nobeep() {
+    _pwm.write(0.0);
+}
+
+/** Beep with given frequency and duration.
+ *
+ * @param frequency - the frequency of the tone in Hz
+ * @param time - the duration of the tone in seconds
+ */
+     
+void Beep::beep(float freq, float time) {
+
+    _pwm.period(1.0/freq);
+    _pwm.write(0.5);            // 50% duty cycle - beep on
+    toff.attach(this,&Beep::nobeep, time);   // time to off
+}
+
+
+
+
diff -r 000000000000 -r 080ef5594cce beep.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/beep.h	Thu Oct 11 20:14:49 2012 +0000
@@ -0,0 +1,59 @@
+#ifndef MBED_BEEP_H
+#define MBED_BEEP_H
+
+#include "mbed.h"
+
+/** class to make sound with a buzzer, based on a PwmOut
+ *   The class use a timeout to switch off the sound  - it is not blocking while making noise
+ *
+ * Example:
+ * @code
+ * // Beep with 1Khz for 0.5 seconds
+ * #include "mbed.h"
+ * #include "beep.h"
+ * 
+ * Beep buzzer(p21);
+ * 
+ * int main() {
+ *        ...
+ *   buzzer.beep(1000,0.5);    
+ *       ...
+ * }
+ * @endcode
+ */
+
+
+namespace mbed {
+
+/* Class: Beep
+ *  A class witch uses pwm to controle a beeper to generate sounds.
+ */
+class Beep {
+
+public:
+
+/** Create a Beep object connected to the specified PwmOut pin
+ *
+ * @param pin PwmOut pin to connect to 
+ */
+    Beep (PinName pin);
+
+/** Beep with given frequency and duration.
+ *
+ * @param frequency - the frequency of the tone in Hz
+ * @param time - the duration of the tone in seconds
+ */
+    void beep (float frequency, float time);
+
+/** stop the beep instantaneous 
+ * usually not used 
+ */
+    void nobeep();
+
+private :
+    PwmOut _pwm;
+    Timeout toff;
+};
+
+}
+#endif