Page 1 of 1

Help no sound through GPIO

Posted: Thu Aug 20, 2020 8:26 am
by tstevens
Hello
First GBZ build. Stuck on sound, tried everthing I can find on sudomod. Wermy's guide, forum searches. Pulling my hair out, hope you can help.
Background:
-Using BW screen modified, working
-Using GPIO pins for buttons from button pcb, retrogame installed to map, working
-Powerboost 1000c (and attached 2500mah lipo) hooked up to DIY powerstrip- powers pi, amp, screen, USB A (also connected to Pi data pads, which is working), working
-Have setup ssh over USB (created ssh file, edited config.txt and cmdline according to https://desertbot.io/blog/headless-pi-z ... sb-windows), working
-Adafruit PAM8302a, 2.5W speaker, 10k ohm vol wheel pot, headphone jack, DIY low pass filter (following guides), NOT WORKING!!!

Audio circuit currently setup according to Rodocop (except headphone Jack) see images:
dezoRtd.jpg
dezoRtd.jpg (96.66 KiB) Viewed 5015 times
InkedIMG_20200820_142404044[95]_LI.jpg
InkedIMG_20200820_142404044[95]_LI.jpg (4.44 MiB) Viewed 5015 times
InkedIMG_20200820_142345869[96]_LI.jpg
InkedIMG_20200820_142345869[96]_LI.jpg (4.09 MiB) Viewed 5015 times
InkedIMG_20200820_142254202[101]_LI.jpg
InkedIMG_20200820_142254202[101]_LI.jpg (4.17 MiB) Viewed 5015 times

Have tried disconnecting/adding parts eg low pass filter, headphone jack, vol wheel. Also swapping different speaker.

Currently on GPIO pin 18 (12th?)
Edited config:
Capture.PNG
Capture.PNG (11.55 KiB) Viewed 5015 times
Is it some software setting I'm missing? In emulationstation? Do I have a conflict with using Retrogame?

Really wanna get audio fixed as I have come so far, its the last piece of the puzzle.
Any help will be greatfully recieved.
Please let me know if you need more details

Re: Help no sound through GPIO

Posted: Fri Aug 21, 2020 9:37 pm
by rodocop
The amp has a small screw pot on it. Which can be used to adjust volume. Maybe that's it? Easiest solution.

As for retrogame. Check is gpio 18 is referenced in it at all...

You could also swap to gpio 13, which is also a pwm pin. You would need to change the config.txt line as well.

Re: Help no sound through GPIO

Posted: Fri Aug 21, 2020 9:46 pm
by rodocop
It's also been a long time since I've done a gbz...but one thing to try is to flip the wiring on the
volume wheel. (If that makes sense, flip it over and wire according to the diagram).

Re: Help no sound through GPIO

Posted: Thu Feb 10, 2022 7:58 am
by hutch78uk
Was any solution found to this issue? Think I'm experiencing something similar :(