Michael Shimniok / Beep

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

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

Beep.cpp

Committer:
shimniok
Date:
2013-07-31
Revision:
0:3eb39e374fc3

File content as of revision 0:3eb39e374fc3:

#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
}