Measuring PWM

Many people in the forum don’t own an oscilloscope when attempting to debug their driver. I came across this website via hackaday to measure the PWM characteristics of a driver without having a scope.

Sweet. Thanks for sharing.

nice - i will give it a try…

For those who don’t know a piezoelectric speaker can be found from those musical cards,cheap electronics etc. They are the flash disc’s that produce beep sounds.

What’s the limit before its a continuous tone and not individual beeps for the app to count?

You can build a DIY oscilloscope for <$10 using a sound card and some bit’s of wire.

I have a scope so I didn’t try this but theory says that there is never a tone since this is a piezo speaker. It only makes noise when the voltage abruptly changes. Also these things have a frequency response that goes well into 20 k I would guess that even at 90% you will still hear a click(really depends on pwn frequency).

Probably sound card will work just as good but really depends on what’s available on hand.