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USB Wifi stops after Stereopi is accessed from Android

Posted: Wed Jul 08, 2020 12:41 pm
by samir_sogay
Hi,

I am using an Alfa AWUS036NHA usb wifi adapter with Stereopi and I am able to ssh stereopi with it and access web interface. As soon as I access stereopi from android and the live stream starts, the wifi stops and also the usb led on the wifi adapter goes away. Is there any power limitation on the usb port as it works perfectly well when I use a powered usb hub for connecting usb wifi adapter? Also, are there any logs generated on the stereopi which I can check as there are no logs on /var/log/syslog, just dmesg which get lost after power cycle.

Thanks

Re: USB Wifi stops after Stereopi is accessed from Android

Posted: Wed Jul 08, 2020 1:15 pm
by Realizator
Hi Samir_sogay,
Power lines to USB ports goes directly from the power source. We did it specially for cases like yours, when you need to connect high-power USB device.
Your Alfa is really hungry for power. Just use more powerful power source, and it should work.
Actually, when you start a livestream, system rise power consumption (cameras are capturing video, GPU encodes videos, and WiFi needs to transmit data).
What kind of power adaptor do you use?

Re: USB Wifi stops after Stereopi is accessed from Android

Posted: Wed Jul 08, 2020 4:04 pm
by samir_sogay
Thanks for your input. Initially I was using a 1Amp power supply. Then I changed to Dlink Hub which has 2.4A output. Even with this it was not working, so I suspected usb port issue. After your reply, I tried another charger with 2.4A output and it worked. This most likely means Dlink was not giving proper output. Thanks for your assistance. Can you tell me if it is possible to take serial console of stereopi as I tried and it didn't work.

Re: USB Wifi stops after Stereopi is accessed from Android

Posted: Wed Jul 08, 2020 5:11 pm
by Realizator
I'm glad it works for you! :-)
As for the UART - we have "enable_uart=1" in /boot/config.txt by default. But we reconfigured UART as a serial com-port for the telemetry data flow. But you can assign UART back to Console using "raspi-config".

Re: USB Wifi stops after Stereopi is accessed from Android

Posted: Wed Jul 08, 2020 5:43 pm
by samir_sogay
I had tried enabling it before via raspi-config and now as well. The settings doesn't seem to persist. After reboot, it gives the option to enable serial via raspi-config. Also, I am getting this error if I exist raspi-config without reboot.

sed: couldn't open temporary file /boot/sedKrLmEO: Read-only file system
/usr/bin/raspi-config: 194: /usr/bin/raspi-config: cannot create /boot/config.txt.bak: Read-only file system
mv: cannot stat '/boot/config.txt.bak': No such file or directory

Re: USB Wifi stops after Stereopi is accessed from Android

Posted: Thu Jul 09, 2020 10:49 am
by Realizator
Ah, raspi-config try to save updated config files, but our filesystem is read-only.
Try to unlock both "/" and "/boot" before the raspi-config:
sudo mount -o rw,remount /
sudo mount -o rw,remount /boot

As for logs - all of them are disabled, as we have a consumer-like approach and read-only filesystem.
If you want to see all output on HDMI, you can turn off the displaying of the video intro and the desktop wallpaper, following steps I mentioned here.

Re: USB Wifi stops after Stereopi is accessed from Android

Posted: Thu Jul 09, 2020 8:53 pm
by samir_sogay
Thanks for the input. Serial console worked.