Simple PWM / beep generation library. Supports timed-duration beeps or infinite length tone generation.

Dependents:   PseudoTheremin NSDL_HelloWorld_WiFi UbloxModemNanoServiceClient IOT-NSDL_HelloWorld ... more

Revision:
0:3eb39e374fc3
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Beep.cpp	Wed Jul 31 23:05:44 2013 +0000
@@ -0,0 +1,29 @@
+#include "mbed.h"
+#include "Beep.h"
+
+/** 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 instantaneously.
+  */
+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, 0 runs indefinitely
+ */     
+void Beep::beep(float freq, float time) {
+
+    _pwm.period(1.0/freq);
+    _pwm.write(0.5);            // 50% duty cycle - beep on
+    if (time > 0)
+        toff.attach(this,&Beep::nobeep, time);   // time to off
+}