GPIO as volume/pitch control

[coolcrab]

So I was wondering how I can setup a blockwave that will change pitch and volume when the sensor gets triggered.
I'm trying to make a alarm that buzzes when someone is near with a higher pich when he is closer.

So lets say 0-3.3v range for 0-100% audio and pitch from low to high. (Can't find any tutorials on doing this.)

Also is it smarter to use the GPIO pins to control the audio or should I use the audio jack port?

[davef21370]

It's either 0v or 3.3v, there's no in between. Look into PWM, that should do your audio. And I'd probably use an ultrasound sensor to measure the distance, pre-built, i2c.

Dave.

[coolcrab]

I got a adc, so its possible

[DougieLawson]

Also is it smarter to use the GPIO pins to control the audio or should I use the audio jack port?

If you can do it with the analog audio jack then that's clearly better. GPIO pins are digital (two states HIGH or LOW, no in betweens).

Most of the hits I found on Google use a Texas Instruments CD4067 analog mux/demux to do volume control