PWM speaker

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1

I got this little 2w speaker Pololu - 18mm Speaker: 4 Ohm, 2.0 W

Using the Tone Buzzer fezzer code here http://code.tinyclr.com/project/149/tone-buzzer-driver/

When just connecting speaker to Di5 and gnd, works fine. Just can’t hear it because of low power.

So I tried to connect to straight 3.3v line via Mosfet breakout http://www.sparkfun.com/products/10256 like below.

However it only clicks a few times and domino reboots in a loop. What am I connecting wrong here? tia

2

Can you try using an external power supply for the MosFet ?
Or adding a big capacitor (220uF ?) between GND and +3V3 ?

3

Forgot my Maf. Added a 6ohm resistor to limit watts <2W and 550mA max draw. Works good.
Writeup here [url]http://staceyw1.wordpress.com/2011/04/02/add-some-sound-to-your-fez/[/url]