All in One PCB Support Thread

[Tomatoflames]

I'm experiencing something similar to the issue reported by @xfcrowman, figured I'd chime in case it helps with troubleshooting:

Issue -
game music through speaker is almost inaudible and cuts out intermittently between random clicks - approximately 2 per second.
Switching to headphones in jack, the game music plays relatively loudly without interruption and moderate static.

Background info -
Tested 2 different speakers with exact same result;
Fresh RP installs, change out wires, and pot have no effect.
Reversing the +/- speaker wires eliminates the game music but the clicking effect continues just the same.

Setup:
PiZero v1.3
Audio parts per Wermy's guide
AIO 2.2a with included audio jack
Retropie 4.1 running with Helder's config.txt file from page 1.

[noebl1]

This has got me wondering too... I am using an external USB sound card and feeding thru instead of the GPIO, and I'm experiencing I think the same thing. The headphone jack is QUITE loud, however the speaker is barely audible, even at max setting. I put an inline amp in, and it works for the speaker, but adds quite a power drop and noise to audio output.

EDIT: The headphones are so loud, that at max volume, their audio output is actually higher than the speaker, and I'm not wearing the head phones but sitting on the desk. I have tried 3 totally different types of speakers as well.

[xfcrowman]

I'm experiencing something similar to the issue reported by @xfcrowman, figured I'd chime in case it helps with troubleshooting:

Issue -
game music through speaker is almost inaudible and cuts out intermittently between random clicks - approximately 2 per second.
Switching to headphones in jack, the game music plays relatively loudly without interruption and moderate static.

Background info -
Tested 2 different speakers with exact same result;
Fresh RP installs, change out wires, and pot have no effect.
Reversing the +/- speaker wires eliminates the game music but the clicking effect continues just the same.

Setup:
PiZero v1.3
Audio parts per Wermy's guide
AIO 2.2a with included audio jack
Retropie 4.1 running with Helder's config.txt file from page 1.

This sounds basically like the same problem I'm having. I was wondering if it is related to the mixing of left and right channels somehow, as the sound cuts in and out quickly as you described. But this is just speculation, I'm really not sure why this problem is occurring.

[enemone]

@helder I unfortunately stripped 2 pads from the channel inputs on the volume wheel pads on the board, and I also stripped the positive pad for the speaker. Do you know of any way that I can regain sound?

[Helder]

This sounds basically like the same problem I'm having. I was wondering if it is related to the mixing of left and right channels somehow, as the sound cuts in and out quickly as you described. But this is just speculation, I'm really not sure why this problem is occurring.

It could be the resistors but they have been used in the past and the value worked fine, you can try maybe 75ohm resistors in place of those 10ohm to the right of the socket and see if that helps or changes anything.

One thing people need to understand is that PWM is not crystal clear digital audio it's analog and therefore has some hiss and pops and is very susceptible to interference from other circuits or power/data lines. So it's best to keep these lines away from the amp and also the volume wheel wires.

@helder I unfortunately stripped 2 pads from the channel inputs on the volume wheel pads on the board, and I also stripped the positive pad for the speaker. Do you know of any way that I can regain sound?

Post a picture of the damage and I'll indicate some alternate points.

[Tomatoflames]

This sounds basically like the same problem I'm having. I was wondering if it is related to the mixing of left and right channels somehow, as the sound cuts in and out quickly as you described. But this is just speculation, I'm really not sure why this problem is occurring.

It could be the resistors but they have been used in the past and the value worked fine, you can try maybe 75ohm resistors in place of those 10ohm to the right of the socket and see if that helps or changes anything.

One thing people need to understand is that PWM is not crystal clear digital audio it's analog and therefore has some hiss and pops and is very susceptible to interference from other circuits or power/data lines. So it's best to keep these lines away from the amp and also the volume wheel wires.



The problem pertains only to the speaker - the sound is almost imperceptible in the speaker and seems to be receiving insufficient power from the amp. As Noebl mentioned, by contrast I can hear game music from the headphone with no problem even when they are just lying on my desk.

[Helder]

What are the specs on the speaker?

[xfcrowman]

What are the specs on the speaker?

Thanks for the suggestion Helder, I will go purchase some 75 ohm resistors. However, I'm not clear on where they need to be connected, or how many are needed.

Using the photo from the first page of your thread, are the relevant points R15 and R16 (highlighted in blue and orange, respectively)? Do I connect the resistors between the color coded points?

The speaker is from Adafruit (Wermy's guide)
https://www.adafruit.com/products/1890



EDIT: Some progress! I had some resistors from another project at home, so I decided to solder them in between the speaker and R16 and R17. It's improved the situation - I still have choppy sound, but the breaks in the sound are not as rapid as before so that you can get most of the game sound. The volume on the speaker has also gone up - it's comparable to the sound I get on the headphone jack.

Any other suggestions to eliminate the problem for good? Maybe I need to connect them to a point before the 10 ohm resistors...

[144TECH]

Your wires from the pi audio are a mile long, and have no shielding at all.. try to use separated wired not 2 wires in one, you could use the grounding from the pi audio, wich is next to the pwm wires. now touch the + audio wire and move it you will hear it getting better or worse. the powerboost also makes alot interference with the audio. just try a shielded audio wire from speakers or anyting what is made for that purpose. the things you described i had them all but was just interference, also a good thing is to make a filter for when there is no audio, this will reduce or remove the interference sounds from the pi and powerboost and so on, as for the speaker i've used a single speaker from minilaptop asus eeepc, and it is LOUD i tell you and clear also it fits in the case also but you need to chop a little plastic away in the middle of the circle. here's a good informative link https://www.youtube.com/watch?v=ENUb4leJ_rM (you need to watch the whole video and take your time, thus not skipping parts)

[144TECH]

@ Helder

I've been testing and testing here like a $%#$@#
It works gamepad detected, settings saved, ok.
Now when i add ( dtoverlay=pwm-2chan,pin=18,func=2,pin2=13,func2=4
disable_audio_dither=1) to the config, thus activating the pwm, and getting input on the PAM chip, it says NO GAMEPAD detected, when removing that what i've added to the config, it starts up and gamepad works.
Could this be that the PAM dragged away this power ? thus leaving not enough energy for everything?
But opposite from this, when i use the cmd and config from the first post it works,(audio is clear no hissing crackling or interference!! ) but sometimes when switching the gbz on it says no gamepad detected... not everytime but it's frustrating i tell you.
I tried this because the cfg and cmd from the first post, makes it boot slower, showing alot more text, and i see LOGIN evertime, it does autologin and goes ahead but i just want to make a clean bootup with some pictures or black screen in between, also the standard retropie joystick image dissapeared.
please gimme some feedback

P.s for others, wiggling with the audio wire(S) can make the pi crash, or reboot and messup the settings. beware
Using another monitor, or adapters will cause a hum from the wall contact, this is not the case when you use a battery

Edit, for as long as there's no solution i'm fine with the cmd and cfg from he first post, it just works fine.

@ Tomatoflames, thanks for pm

your wiring seems to be ok.. but i notice that your 5v wires are hanging over the audio wires this causes the power to interfere with the speaker wires, try regular speaker wire wich is insulated and isolated (just one wire with metal shielding around in insulated wire)
But you really have to get away from the power wires. and keep everything as short as possible.
Also if your powerboost is whistling, place a piece of tape ontop of it this keeps the thing from whistling, mine did too.