Audio noise w/ WaveShare 1.3 IPS HAT (SOLVED)
Posted: Sat Sep 15, 2018 9:14 am
I'm working on a Pi0cket style mni Raspberry Pi 0 (non-wifi) build to run retropie on.
Originally I was testing out the WaveShare 1.44inch TFT LCD/Button hat and I wired audio up to GPIO 18 with out issue.
I then swapped the display to the WaveShare 1.3inch ISP LCD/Button hat and began getting horrible whine in the audio. (Same exact wiring).
Below is my setup
Raspberry Pi Zero
WaveShare 1.33 IPS Hat https://www.waveshare.com/w/upload/6/6b ... ual_en.pdf
B103 10k Pot https://www.amazon.com/gp/product/B00O9 ... UTF8&psc=1
PAM8403 2channel amp https://www.amazon.com/gp/product/B00XA ... UTF8&psc=1
I'm only concerned with single channel audio as I will pretty much only be playing NES on this device ( and GPIOs 13 and 19 are taken up by the buttons on the hat)
I've added the following lines to my /boot/config.txt
dtoverlay=pwm,pin=18,func=2
disable_audio_dither=1
force_pwm_open=0
With force_pwm_open=0 set, the hiss/whine only occurs while a game is loaded, with out that option the hiss/whine starts at first game load and continues to reboot.
I've tried several wiring options, and even pulling audio from GPIO12 (its been such a train wreck the past 2 days trying to rid the whine noise, I'm fairly sure I got no audio out of GPIO12, even when assuring my settings are correct)
Lastly I've tried powering the AMP from an external power supply, but the whine persisted.
Below is my current wiring diagram. Be gentle, I spent 32 hours in MSPaint on it
Originally I was testing out the WaveShare 1.44inch TFT LCD/Button hat and I wired audio up to GPIO 18 with out issue.
I then swapped the display to the WaveShare 1.3inch ISP LCD/Button hat and began getting horrible whine in the audio. (Same exact wiring).
Below is my setup
Raspberry Pi Zero
WaveShare 1.33 IPS Hat https://www.waveshare.com/w/upload/6/6b ... ual_en.pdf
B103 10k Pot https://www.amazon.com/gp/product/B00O9 ... UTF8&psc=1
PAM8403 2channel amp https://www.amazon.com/gp/product/B00XA ... UTF8&psc=1
I'm only concerned with single channel audio as I will pretty much only be playing NES on this device ( and GPIOs 13 and 19 are taken up by the buttons on the hat)
I've added the following lines to my /boot/config.txt
dtoverlay=pwm,pin=18,func=2
disable_audio_dither=1
force_pwm_open=0
With force_pwm_open=0 set, the hiss/whine only occurs while a game is loaded, with out that option the hiss/whine starts at first game load and continues to reboot.
I've tried several wiring options, and even pulling audio from GPIO12 (its been such a train wreck the past 2 days trying to rid the whine noise, I'm fairly sure I got no audio out of GPIO12, even when assuring my settings are correct)
Lastly I've tried powering the AMP from an external power supply, but the whine persisted.
Below is my current wiring diagram. Be gentle, I spent 32 hours in MSPaint on it