Wifi troubles with Rpi3 & 2.114


I’ve upgraded to 2.114 recently and have trouble with my wifi connection on my RPi3. I’m using a EW-7612UAN V2 WiFI dongle because of the imcompatibility of the HifiBerry and the on-board wifi module. The reception is usually quite good as the wifi router is in the room next door.

2.041 ran for a couple of months with ok’ish wifi stability. Maybe once in every 2 weeks the connection would be lost and I had to manually connect to the volumio hotspot and switch back to my network. Also, after a reboot, it would not connect to my network but end up in hotspot mode. While this was not ideal, it was manageable.

Now, with 2.114, things are similar but way worse. When I upgraded to the latest dev version last weekend or so I noticed it already but the problem went away during the week. A couple of hours ago it happened again. Now, it is in the situation where manually switching to my wifi network does not work at all. It connects for what seem to be a couple of seconds but immediately goes back to hotspot mode. Also, my network is sometimes not even listed in the UI. Only after a couple of refreshs it is there. Eventually after waiting a couple of hours and reboots it works again.

I have the suspicion that it might be the case that volumio is not waiting long enough for the network discovery. From the the pi stands, it receives ~10 networks sometimes and the discovery seems to be only gradually populating the list until all of them are available. So, if there are 10 networks it takes longer for the full scan. Maybe on weekends there are more wifi networks than on weekdays…

When I execute

sudo iwlist wlan0 scan

my network sometimes shows up immediately and sometimes after a couple of calls. Not sure whether the wifi dongle is doing the scan in the background or the scan command is just randomly waiting for broadcasts for a while.

What can I do to improve this situation?

Can I hardcode my wifi ssid somewhere so that the system always tries to connect there?
Can I increase the network scan timeouts?