BBB Rev C - ping responses after a delay.


I am getting responses to my pings after about the 12th attempt or so. This is after a long time accessing the BBB for anything. In other words no access to BBB for a long time. Then sending ping requests, it responds with
From icmp_seq=2 Destination Host Unreachable
From icmp_seq=3 Destination Host Unreachable
From icmp_seq=4 Destination Host Unreachable
From icmp_seq=6 Destination Host Unreachable
From icmp_seq=7 Destination Host Unreachable
From icmp_seq=8 Destination Host Unreachable
From icmp_seq=10 Destination Host Unreachable
From icmp_seq=11 Destination Host Unreachable
From icmp_seq=12 Destination Host Unreachable
64 bytes from icmp_seq=13 ttl=64 time=208 ms
64 bytes from icmp_seq=14 ttl=64 time=1.64 ms
64 bytes from icmp_seq=15 ttl=64 time=3.09 ms

My OS is Ubuntu and uname -a shows:
Linux arm 3.14.33-ti-r50 #1 SMP PREEMPT Thu Feb 12 03:52:59 UTC 2015 armv7l armv7l armv7l GNU/Linux

I am using TP-Link wifi dongle - TP-725N and I followed the instructions on the URL shown below to install the required drivers.

The wifi link is up and functional for as long as I am logged in or working on it. If there is no activity for extended periods of time, I see the above ping behavior.

My use case:

I am using the BBB with Opensprinkler to control my irrigation valves. I was able to integrate the h/w + s/w and mounted the entire set up in the same location where my previous irrigation controller was. I use the application once every 3 days. The app times out and it cannot connect to the BBB. I have to walk to the location where the controller sit and remove power wait a few seconds and connect back the power. Then the app is accessible. BBB gets it power (5V) from the opensprinkler h/w. The opensprinkler h/w takes 25V A/C.

So I removed my installation and brought my BBB + Opensprinkler h/w inside my home and have been trying to see if this thing will stay up for days together without any activity. It is about 24hrs and I am seeing this ping behavior. How can I keep it active all the time and respond immediately. It may be an overkill as the computer is working even when there is no irrigation valves to be activated or de-activated. At first my suspicions were on the BBB and was thinking it was hung. But /var/log/syslog does not show any errors. I can see the DHCPDISCOVER for eth0 wake up and try to get an IP but since nothing is connected to the eth0 port, it goes back to sleep.

Any thoughts or pointers as to where I can look for some solution. I also had a small cron job run every 5 minutes on the BBB, it would do ps -ef redirect the output to /dev/null and then ping my router for 3 times. I captured the ping output in a log file and I keep overwriting the log file and I see it having the most recent time stamp mapping to the last 5 minute interval indicating that the board has been working without failures. But I have to resort to the rebooting the board because my app is not able to connect to the BBB.

Thank you and appreciate your time.


Either disable hdmi or add a small usb extension cable to move that
small wifi device away from the active hdmi ground plane.