Piezo volume too soft

[marknano]

I need the piezo speaker that came with the arduino starter kit to make a loud buzzer when called. The tone that comes out of it is very soft. I connected It to pin 9 in series with a 100ohm resistor to ground. The code that i use to call it is "tone(9, NOTE_C4, 1000)". First argument is the pin#, 2nd is the note, and the 3rd is the duration. I dont need a complicated sound. Just a basic loud buzzer enough to be heard from 20 feet. Please help.

[adafruit_support_mike]

First, try removing the 100ohm series resistor. A piezo element is roughly like a capacitor electrically, so you don't have to worry about current flowing through it. All the resistor does is slow down the current charging the piezo element, which means it moves slower, thus producing less volume.

If that doesn't do the job, try the reference circuit in the datasheet:

http://www.tdk.co.jp/tefe02/ef532_ps.pdf (last page)

An Arduino can only deliver about 40mA of current per pin, so it's not really an audio drive circuit. A good transistor can move a lot more current (the 2N7000 mosfet is rated for 500mA of pulsed current, and the SS8050 bipolar can swing 1.5A aound).

A transistor will also let you use a separate, higher voltage power supply for the piezo element. It's rated for up to 30v, so a 12v wall wart should give you plenty of power.

[marknano]

Removig the resistor did not do anything with the volume. I will try the transistor. Thanks.

[adafruit]

Try 4000 Hz - thats the loudest tone

[marknano]

Try 4000 Hz - thats the loudest tone

Please send me a code that will make me produce 4000hz. I am new o arduino and I do not know about sounds yet. Thanks.

[adafruit_support_bill]

There is a functin for that in the Arduino language:
http://arduino.cc/en/Reference/Tone