Simon Anthony
Create a beeping alarm that starts and stops when you want it to. Created for OspreyQuad project and intended for use with a piezo buzzer.
Diff: alarm.cpp
- Revision:
- 0:60cd02d169ea
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/alarm.cpp Sun Jan 19 13:03:30 2014 +0000
@@ -0,0 +1,35 @@
+#include "mbed.h"
+#include "alarm.h"
+
+using namespace mbed;
+
+Alarm :: Alarm(PinName pin) : _pwm(pin)
+{
+ _pwm.period(1.0/1000);
+ _pwm.write(0.0);
+ active = false;
+}
+
+void Alarm :: startBeep(void)
+{
+ active = true;
+ beepOn();
+}
+
+void Alarm :: stopBeep(void)
+{
+ active = false;
+}
+
+void Alarm :: beepOn(void)
+{
+ _pwm.write(0.5);
+ beepTimer.attach(this, &Alarm::beepOff, 0.1);
+}
+
+void Alarm :: beepOff(void)
+{
+ _pwm.write(0.0);
+ if(active)
+ beepTimer.attach(this,&Alarm::beepOn, 0.05);
+}
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