Problems with the SX/B Sound Command setup.

DWinchell

Hi All :-)
·
I have been playing with the sound command. I used the Piezo speaker and two 10uF caps from the "What is a Microprocessor" development set. According to the information in the SX/B Help file under Commands/Sound the schematic calls for a cap to the SX chip port pin and to the + on the Piezo speaker. Then also a cap across the Piezo speaker. The sound was so faint I could not hear it. After advice from Parallax I removed the cap across the Piezo speaker and the sound level was loud enough to hear from 20 feet away in a quiet space. What worked was the + pin on the 10Uf cap to a SX port pin. The – pin on the 10uF cap to the + pin on the Piezo speaker. The – pin on the Piezo speaker to ground.
·
Thank You
David Winchell

Jon Williams

I changed the parallel cap to 0.1 after some experiments. While my experiments (using a piezo and an amp) weren't as dramatic as yours, there was a noticable difference when using 10 uF to ground. That said, the sound was smoother, probably due to the early HF roll-off.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax
Dallas Office