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PWM Audio / Config.txt File Question

Posted: Mon Jul 25, 2016 3:10 pm
by MacBean
Hey Everyone,

My build is completely done except for one lingering problem I can't seem to figure out. I'm not being able to get audio out of my Zero. I have double checked my wiring several times and when I plug in headphones I hear static/fuzz or whatever you wanna call it. I think my problem might have to do with my config.txt file.

I'm new to all of this so can someone please clear this up for me... when I add the line dtoverlay=pwm,pin=18,func=2 to the end of your config.txt file does it replace something? Should I be adding a # first? Should there be no #? If the is supposed to be a # do you put a space between the # and dtoverlay=pwm,pin=18,func=2 ?

If someone could explain this to me that would be great... or if someone wants to simply copy and paste their complete funtional config.txt file copy for me I would be so grateful.

Thanks! :D

Re: PWM Audio / Config.txt File Question

Posted: Tue Jul 26, 2016 7:39 am
by Ganreizu
There is already a dtoverlay line in config by default. Find it and replace it with that line to get audio so long as the wiring is correct.

# is what it uses to comment out code. If there's a hashtag in front of a line, that means the pi will IGNORE that line and those settings.

Re: PWM Audio / Config.txt File Question

Posted: Wed Jul 27, 2016 4:12 pm
by PotaTox
Bumping this, the same thing is happening to me

Re: PWM Audio / Config.txt File Question

Posted: Wed Jul 27, 2016 4:38 pm
by Ganreizu
...but i already answered it...?

Re: PWM Audio / Config.txt File Question

Posted: Wed Jul 27, 2016 5:50 pm
by statikeffeck
You get no sound at all? You have the low pass filter installed and are connected to the correct pins?

Check all your connections, and try first without hooking up your amp, just the headphones to the filter, which then goes to the pi.

Re: PWM Audio / Config.txt File Question

Posted: Wed Jul 27, 2016 8:01 pm
by PotaTox
statikeffeck wrote:You get no sound at all? You have the low pass filter installed and are connected to the correct pins?

Check all your connections, and try first without hooking up your amp, just the headphones to the filter, which then goes to the pi.
I have Helders all in one board, so I can't do that.

Re: PWM Audio / Config.txt File Question

Posted: Wed Jul 27, 2016 10:53 pm
by Ganreizu
PotaTox wrote:I have Helders all in one board, so I can't do that.
Can you and macbean post your config file? Then we can see if the settings are off and try to fix it.

Re: PWM Audio / Config.txt File Question

Posted: Mon Oct 03, 2016 11:22 am
by laluva
Have added this line to the config txt: dtoverlay=pwm,pin=18,func=2

Line out is taken from gpio 18 and ground from the nearby groundpoint, goes through homemade filter a amp and to speaker.
Ofcourse with my luck/experience no sound, only very low hizz noise from speaker when i connect power to the amp.

Can i connect speaker directly to gpio 18 and ground to hear some sound from retropie?

Just to confirm that sound out from zero is okay?