configuring the Yun wifi access

To change/select which WLAN access point the Yun should use you can just edit the following file:

     /etc/config/wireless

Just change the SSID and key.

Getting the status of the wifi:

      iwconfig wlan0

wifi monitor to troubleshoot Yun wifi - Results

RESTART_... = true,
sketch: simple LED blink
2014-07-25 08:11 : wifi OK, uptime=6:59:04.868013, ok/nok: 2310/3
no particular pattern

wifi monitor to troubleshoot Yun wifi

My Yun's wifi seems to be very unstable.

I created a python script to monitor the Yun's wifi connection.

This script can be downloaded here.

The main script is wifiMonitor.py

There are 4 things that are supposed to be configured (see wifiMonitor.py):

LOGFILE="/tmp/wifiMonitor"
LOGFILESD="/mnt/sda1/arduino/wifiMonitor_"
RESTART_WIFI_WHEN_LOST = True
TO_PING = "192.168.1.1"

The first 2 give the location of where the logs are stored: LOGFILE is the main destination, with now and then a backup to LOGFILESD.
When it sees the wifi coonection is lost, it will either:
- do nothing (just wait and hope it gets restored)
- restart the Yun's wifi
This is configured by the RESTART_WIFI_WHEN_LOST option.
To determine if the Wifi is ok, it will ping a particular site or IP address. This is set by the TO_PING option. In my case I just ping my router.

In short the script will now and then ping to TO_PING site to determine if Wifi is ok and do the appropriate action if not. It logs the ratio of ok/not_ok and the current uptime.

Arduino Yun Wifi stuff (reset, access point mode, ...)

The Yun has 3 reset buttons: one of those is a Wifi reset button (WLAN Rst)

Depending on how long you press the button the following will happen (I think):

• Pressing the WLAN Rst button for <5 sec does not do any reset at all, correct (it just lets a LED blink)
• Pressing the Wifi Rst button for >=5 but <30 sec will run the wifi-reset-and-reboot script. This script will return the Yun in access point (AP) mode and will reboot the Yun. The Yun should then present its network SSID.
• Pressing for >= 30 sec will restore some factory settings

If you just want to reset the Wifi, you can do this with the wifi script (should be in /sbin):

    root@Arduino:/tmp# wifi down && sleep 5 && wifi
    Successfully initialized wpa_supplicant

You probably can also do:

    ifconfig wlan0 down; ifconfig wlan0 up

Note that rc.local contains by default the entry wifi-live-or-reset. After the Yun boots, it will check for the configured Wifi network. If it is not found within 60sec, the Yun will go into access point mode.