Joseph Roberts
Make noise with a piezo buzzer. Use a digital out pin.
Fork of
beep
by 
Peter Drescher
This is a simple non blocking library to turn on the pin passed into the constructor for the amount of time specified when calling the beep(float time) function.
I use it to turn on a buzzer but it could be used for anything you need to turn on for a set time.
Diff: beep.cpp
- Revision:
- 4:d8e14429a95f
- Parent:
- 3:5a8242af60ba
- Child:
- 5:372aa7360db7
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/beep.cpp Tue Sep 11 08:21:45 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
+}
+
+
+
+