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GBZ Audio Support

Posted: Fri Sep 14, 2018 6:44 am
by Chris21788
Hey everyone. Started building my first GBZ a few days ago, and am stuck on audio...everything is working as expected. I'm planning on creating a wiring diagram for my entire build once it's complete, and I'll share with the forums (you can never have too many!), but I can't get audio to work.

I'm using a generic PRS-TECH.com PCB board (only for controls), so I need to do everything outside from that.

The end goal for me is to wire up a few things for audio:
  • Raspberry Pi Zero
    Adafruit PAM8302
    8O 1W speaker
    5 pin Potentiometer
    PJ-325 Headphone Jack
For now, I'd like to know that just audio works, so I'm trying to wire up just the speaker. I've tried the following, but am not getting anything but noise/static out of the speaker:
Image

The following is in my /boot/config.txt as the very last line:

Code: Select all

dtoverlay=pwm,pin=13,func=2
I've searched all over, but can't find anything specific to the above setup...Suggestions or anything else I can look at?

Re: GBZ Audio Support

Posted: Fri Sep 14, 2018 10:19 am
by tinkerBOY
Try using gpio18 instead.

Re: GBZ Audio Support

Posted: Fri Sep 14, 2018 10:26 am
by KonnorJ

Re: GBZ Audio Support

Posted: Fri Sep 14, 2018 6:17 pm
by Chris21788
GPIO18 fixed it for me. I don't know why I thought that pin was already in use, but it wasn't.

But now, I believe I fried my display. It only displays white now (Pi works via HDMI)...screen is always white.

EDIT: Correction... There's actually the console there. I don't know what's going on. Straight on, it's white. Angle it a bit, and you see the BIOS startup text.

Image
Image

I've disconnected everything from the PI (even tried a 2nd one). Here's the pinouts:
Image

Thanks in advance

Re: GBZ Audio Support

Posted: Mon Sep 17, 2018 6:52 am
by Ely
Maybe you forgot the GND of your screen.
From your screen to the Pi, I can see TV1 and 2 used (yellow and black wire), a red wire for the 5V but no wire for your GND.