Make noise with a piezo buzzer. Use a digital out pin.
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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.
Revision 2:a34405c20cf5, committed 2011-02-01
- Comitter:
- dreschpe
- Date:
- Tue Feb 01 19:17:44 2011 +0000
- Parent:
- 1:ddccf0a4a414
- Child:
- 3:5a8242af60ba
- Commit message:
- 0.3
Changed in this revision
beep.c | Show annotated file Show diff for this revision Revisions of this file |
--- a/beep.c Tue Feb 01 19:08:44 2011 +0000 +++ b/beep.c Tue Feb 01 19:17:44 2011 +0000 @@ -1,19 +1,49 @@ #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 } -// switch off + /** stop the beep instantaneous + * usually not used + */ void Beep::nobeep() { _pwm.write(0.0); } - -// beep +/** 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);