View Full Version : Using BS2 to emulate "ding-dong" sound of a door bell

09-11-2008, 10:52 AM
Hello everyone,

Does anyone know how to emulate the "ding-dong" sound of a door bell using a BS2. I think I've seen some examples using the SEROUT command to generate tones.


Phil Pilgrim (PhiPi)
09-11-2008, 12:00 PM
Try this:

FREQOUT Speaker, 500, 600, 601
FREQOUT Speaker, 500, 500, 501

Each FREQOUT blends two tones that are 1 Hz apart in frequency. They start out in phase, which means their amplitudes add. By 1/2 second (500 ms) later, they are 180 out of phase, which means their amplitudes cancel. What this yields is a tone with a fast attack and a 1/2-second decay, rather like a bell. It's not perfect, but it's about the best you'll get with the Stamp. Unfortunately, you can't extend the tone beyond 1/2 second, wihout it increasing in amplitude again. Doing so produces a "wow" effect instead of a continued decay.


'Still some PropSTICK Kit bare PCBs (http://forums.parallax.com/showthread.php?p=729096) left!

09-12-2008, 07:55 AM
That's close enough. Thanks, Phil!