I thought I read somewhere that the Yun will automatically fall back to AP mode if it can't connect to a previously configured wifi for a pre-defined amount of time.
Is that really true or did I imagine that ? The hardware page doens't say anything like that; it seems like the only way to fall-back to AP mode is to hit the wifi reset more than 5 seconds.
If the answer is yes, then is there a way to disable that behavior ? I want my Yun to keep trying to connect to the pre-configured wifi forever. This is because sometimes, my wifi may temporarily power down, or get restarted, or the Yun may get out of range of my wifi. If the Yun then switches to AP mode then how will my Arduino sketch gain internet access again (without me having to reconfigure the Yun) ???
I believe commenting wifi-live-or-reset by putting a # before it in /etc/rc.local (or the luci web interface) will disable that but Federico would be the authority on how this is best done.
Thanks for the hint.
I can't see this automatic fall back to AP mode. Here's what I did :
I picked the Xively example and modified it so that it reports the exitValue() of the Xively process; I load it on the Yun which has been configured to connect to my wifi. Then I watch it send data to Xively over and over (I upload every 15 seconds). At some point, I unplug my router. A few seconds later, I see the Yun trying to connect to Xively; it fails and fails repeatedly for the next three-four minutes. Then I power up my router again. A few seconds later the Yun reconnects to it and continues uploading data again successfully...
So I guess there is no "automatic fallback to AP mode" ; or (more likely) I don't understand under what circumstances that happens.
I'll wait to see what Federico says...
I confirm the fall back, but it's only activated at yun startup, when wifi starts.
If your wifi router fails (like when you powered it off) WHILE the yun was using it, the yun won't do anything. Since it's pretty common to have intermittent network outages (especially with wifis), the yun will just sit and wait forever.
If instead, your wifi router/hotspot is off (or broken, like the one we had in the office) while the yun is STARTING, the yun will wait for your router for 60 seconds. Only then, not having found a router to connect to, it will fall back to AP mode.
BTW, when back to AP mode, you don't need to reconfigure it. Just power back on your router and unplug/replug the yun. It will retry connecting to your router with the previous configuration.
Ok thanks for explaining !