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Sound output pwm wont work(SOLVED)
Posted: Tue May 16, 2017 3:27 pm
by TilenB

- testb_bb.png (184.71 KiB) Viewed 9455 times
the sound wont work... now let me explain my wiring(pi to amp)
-I am doing only mono, this is why only one half of the low pass filter
-yellow wire out of low pass filter goes to the potentiometer
-I accidently bought a stereo amp, this is why I bridged the connection that comes out of the potentiometer to L+ and R+
-same goes for R- and L- which are connected to ground
amp out:
L- & R- = headphone ground
L+ =Left in
R+=Right in
Speaker + = Left out
Speaker - = Headphone ground
what am I doing wrong?
Re: Sound output pwm wont work
Posted: Tue May 16, 2017 3:32 pm
by moosepr
Have you added the command into the config file to activate the sound?
https://learn.adafruit.com/adding-basic ... -pwm-audio
Re: Sound output pwm wont work
Posted: Tue May 16, 2017 3:40 pm
by TilenB
yes I have.
Re: Sound output pwm wont work
Posted: Wed May 17, 2017 1:30 am
by Lphillimore
That doesn't look like the right PWM pin you're using on the Pi.
PWM audio on the Pi uses pins 13 and 18 by default and as per config change.
See purple and blue as below.

- 20170517_152756.png (1.12 MiB) Viewed 9437 times
Re: Sound output pwm wont work
Posted: Wed May 17, 2017 3:43 am
by TilenB
this is my wiring on the rpi red cable is pin 18 i think or have I counted wrong?
Re: Sound output pwm wont work
Posted: Wed May 17, 2017 4:04 am
by moosepr
yeah your in pin 24
just dont forget to mirror it, as the diagram is from the top, and your photo is from the bottom
Re: Sound output pwm wont work
Posted: Thu May 18, 2017 2:57 pm
by Lphillimore
@TilenB - how did you get on?
Re: Sound output pwm wont work
Posted: Fri May 19, 2017 12:30 pm
by TilenB
Lphillimore wrote: ↑Thu May 18, 2017 2:57 pm
@TilenB - how did you get on?
I resoldered it now I'm gonna do the programming again I'll tell you if it works when I'm done
Re: Sound output pwm wont work
Posted: Fri May 19, 2017 1:10 pm
by TilenB
nah still cant get it to work I really dont know what the problem is
Re: Sound output pwm wont work
Posted: Fri May 19, 2017 1:21 pm
by TilenB
could the volume wheel be the problem?..
Pins from left to right:
1- empty
2- R out
3- R in
4- empty
5-ground