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Distinguish between BUZZER and SPEAKER (PR#2513)

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A speaker needs a AC or a pulsed DC to make a sound, a buzzer only needs a DC.
A buzzer has it's own resonator. It works in most cases to feed the buzzer with a pulsed DC, but the sound will not be as loud as with pure DC.

There seem to be boards where the BEEPER-pin is not able to handle a PWM. Obviously intended for a buzzer.
To make these board able to handle a speaker

* replace the PWM based tone()-function again with a on-delay-off-delay loop.

Hopefully the last time I touch the beeper code.
This commit is contained in:
AnHardt
2015-07-24 23:19:09 +02:00
committed by Richard Wackerbarth
parent 53d9c9ff23
commit fd0e81b0c7
18 changed files with 32 additions and 2 deletions
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17
Marlin/buzzer.cpp
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@@ -9,8 +9,21 @@
lcd_buzz(duration, freq);
#elif defined(BEEPER) && BEEPER >= 0 // on-board buzzers have no further condition
SET_OUTPUT(BEEPER);
tone(BEEPER, freq, duration);
delay(duration);
#ifdef SPEAKER // a speaker needs a AC ore a pulsed DC
//tone(BEEPER, freq, duration); // needs a PWMable pin
unsigned int delay = 1000000 / freq / 2;
int i = duration * freq / 1000;
while (i--) {
WRITE(BEEPER,HIGH);
delayMicroseconds(delay);
WRITE(BEEPER,LOW);
delayMicroseconds(delay);
}
#else // buzzer has its own resonator - needs a DC
WRITE(BEEPER, HIGH);
delay(duration);
WRITE(BEEPER, LOW);
#endif
#else
delay(duration);
#endif