RTL8188CUS Keeps Dropping Signal

[glencoe]

I purchased a RTL8188CUS to use WiFI with my Pi that was built to use as a digital display on the back of a TV. We want wireless for obvious reasons.

It had been working fine for the past week without any issues, I've had it connected to the TV to making sure its pulling the correct information on the correct days.

When I came in yesterday it was showing the day before content. I couldn't figure out why in the Digital Display software so I tried to connect via SSH to the Pi. It was locked up hard and I had to pull the plug to reboot it.
I left it and came back today to find that the Digital Display software could not see the Pi anymore and I could not connect over SSH or Ping the IP. I got 'Host is down'. Again I had to pull the plug.

The digital display software automatically reboots the machine nightly at 3am to ensure clean caches and hopefully prevent issues (I am running 3 Windows PCs right now with the same setup, no issues).

Now, I'm not a huge linux guy, but I can follow directions.
Looking around I have not found a solution and judging by the information I got from running iwconfig, it appears everything is setup right and I have a good connection (The Wireless access point is in my office, so I would hate to see what would happen outside the office!)

The Pi is being powered via power adaptor plugged into the wall, and the WiFi dongle is the only thing in the USB ports. is it really the case that even when connected to power I will need a powered hub? If so, I need a better solution.

Does anybody see any issues here? Is there other commands I can run to see what the issue might be? A lot of this doesn't really make sense to me right now...


Below is from 'messages' You can see the reboot finish at 3am then at 6:17 it seems to start up again but nothing inbetween...

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Mar 21 03:00:57 raspberrypi wpa_action: creating sendsigs omission pidfile: /run/sendsigs.omit.d/wpasupplicant.wpa_supplicant.wlan0.pid
Mar 21 03:00:58 raspberrypi wpa_action: bssid=00:00:00:00:00:00 (modified this to 0s)
Mar 21 03:00:58 raspberrypi wpa_action: ssid=myssid
Mar 21 03:00:58 raspberrypi wpa_action: id=0
Mar 21 03:00:58 raspberrypi wpa_action: mode=station
Mar 21 03:00:58 raspberrypi wpa_action: pairwise_cipher=CCMP
Mar 21 03:00:58 raspberrypi wpa_action: group_cipher=CCMP
Mar 21 03:00:58 raspberrypi wpa_action: key_mgmt=WPA2-PSK
Mar 21 03:00:58 raspberrypi wpa_action: wpa_state=COMPLETED
Mar 21 03:00:58 raspberrypi wpa_action: ip_address=10.100.2.34
Mar 21 03:00:58 raspberrypi wpa_action: address=00:13:ef:d0:04:92
Mar 21 06:17:20 raspberrypi kernel: imklog 5.8.11, log source = /proc/kmsg started.
Mar 21 06:17:20 raspberrypi rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="2009" x-info="http://www.rsyslog.com"] start

From my syslog. A few lines right after the 3am reboot

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Mar 21 03:00:58 raspberrypi dbus[2129]: [system] Successfully activated service 'org.freedesktop.PolicyKit1'
Mar 21 03:00:58 raspberrypi dbus[2129]: [system] Successfully activated service 'org.freedesktop.ConsoleKit'
Mar 21 03:02:39 raspberrypi dhclient: isc-dhclient-4.2.2
Mar 21 03:02:39 raspberrypi dhclient: isc-dhclient-4.2.2
Mar 21 03:02:41 raspberrypi dbus[2129]: [system] Activating service name='org.freedesktop.UDisks' (using servicehelper)
Mar 21 03:02:41 raspberrypi dbus[2129]: [system] Successfully activated service 'org.freedesktop.UDisks'
Mar 21 03:03:21 raspberrypi crontab[2959]: (root) LIST (pi)
Mar 21 03:17:01 raspberrypi /USR/SBIN/CRON[3301]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Mar 21 04:01:40 raspberrypi wpa_supplicant[1745]: wlan0: WPA: Group rekeying completed with 70:56:81:c9:3a:39 [GTK=CCMP]
Mar 21 04:17:01 raspberrypi /USR/SBIN/CRON[4126]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Mar 21 05:01:40 raspberrypi wpa_supplicant[1745]: wlan0: WPA: Group rekeying completed with 70:56:81:c9:3a:39 [GTK=CCMP]
Mar 21 05:17:01 raspberrypi /USR/SBIN/CRON[4956]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Mar 21 06:01:40 raspberrypi wpa_supplicant[1745]: wlan0: WPA: Group rekeying completed with 70:56:81:c9:3a:39 [GTK=CCMP]
Mar 21 06:17:01 raspberrypi /USR/SBIN/CRON[5772]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Mar 21 06:17:20 raspberrypi kernel: imklog 5.8.11, log source = /proc/kmsg started.
Mar 21 06:17:20 raspberrypi rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="2009" x-info="http://www.rsyslog.com"] start
Mar 21 06:17:20 raspberrypi kernel: [    0.000000] Booting Linux on physical CPU 0x0

And some additional info.

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pi@raspberrypi /var/log $ iwconfig
wlan0     IEEE 802.11bgn  ESSID:"myssid"  Nickname:"<WIFI@REALTEK>"
          Mode:Managed  Frequency:2.412 GHz  Access Point: 00:00:00:00:00:00 (Modified to 0s)
          Bit Rate:72.2 Mb/s   Sensitivity:0/0  
          Retry:off   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=100/100  Signal level=90/100  Noise level=0/100
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

lo        no wireless extensions.

eth0      no wireless extensions.

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pi@raspberrypi /var/log $ ifconfig
eth0      Link encap:Ethernet  HWaddr b8:27:eb:3e:46:33  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:1927 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1927 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:139949 (136.6 KiB)  TX bytes:139949 (136.6 KiB)

wlan0     Link encap:Ethernet  HWaddr 00:13:ef:d0:04:92  
          inet addr:10.100.2.34  Bcast:10.100.x.xxx  Mask:255.255.248.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:29330 errors:0 dropped:2216 overruns:0 frame:0
          TX packets:9369 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:6083662 (5.8 MiB)  TX bytes:3236996 (3.0 MiB)

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pi@raspberrypi /var/log $ lsmod
Module                  Size  Used by
snd_bcm2835            16165  0 
snd_soc_bcm2708_i2s     5474  0 
regmap_mmio             2806  1 snd_soc_bcm2708_i2s
snd_soc_core          131268  1 snd_soc_bcm2708_i2s
regmap_spi              1897  1 snd_soc_core
snd_pcm                81593  2 snd_bcm2835,snd_soc_core
snd_page_alloc          5156  1 snd_pcm
regmap_i2c              1645  1 snd_soc_core
snd_compress            8076  1 snd_soc_core
8192cu                550816  0 
snd_seq                53769  0 
snd_timer              20133  2 snd_pcm,snd_seq
snd_seq_device          6473  1 snd_seq
leds_gpio               2059  0 
led_class               3688  1 leds_gpio
snd                    61291  7 snd_bcm2835,snd_soc_core,snd_timer,snd_pcm,snd_seq,snd_seq_device,snd_compress

[adafruit_support_mike]

`ifconfig` says the device has an IP address and has been transmitting data. It looks like you got a few dropped packets, but not at a rate to cause huge concern.

Your IP schema is slightly unusual.. I don't often see 255.255.248.0 as a netmask, but can't think of any reason why that should cause problems.

The "Group rekeying" messages are a sign that the connection was working at those times. WPA uses a shared key with a short lifespan (usually about an hour) and negotiates a new key with all the clients periodically. If wlan0 updated its key, it had to be talking to the server.

Given the system information you've shown, I'd say the basic network connection is good, and you need to look for problems further up the protocol stack.