[Solved] PWM Audio problems

[xaman]

Hi guys!

I'm building my first GBZ. Almost everything is working, I have been playing for hours, but I can't fix the PWM audio.
First of all, some info:
-I'm using the last version of Recalbox
-I decided not to use a Teensy, all the buttons are wired to the GPIO pins.
-The GPIO18 (usually PWM0) is used by the Y button. I followed this scheme:

547808GPIO.jpg (197.87 KiB) Viewed 2519 times

-I built a low-pass filter following this design:

gYXyuT1.png (34.28 KiB) Viewed 2519 times

-I tried different PWM configurations using these references:

Screen Shot 2017-03-01 at 23.59.54.png (517.12 KiB) Viewed 2519 times

-I'm using a PAM8403 amplifier. I followed this scheme to wire it:

Screen Shot 2017-03-01 at 23.58.56.png (570.14 KiB) Viewed 2519 times

-The speaker is rusty, I know, but I'm using earphones to test the audio output.

The output is just noise (like an old modem sound). I tried to use GPIO13 and GPIO19 as PWM audio outputs with the following configuration:

Code: Select all

dtoverlay=pwm,pin=13,func=4
// OR
dtoverlay=pwm,pin=19,func=5

Some pictures:

20170228_022653.png (1.39 MiB) Viewed 2519 times

20170301_230512.png (1.36 MiB) Viewed 2519 times

20170301_230445.png (1.23 MiB) Viewed 2519 times

Please, help me, I don't know where is the problem