Friday, May 31, 2013

Reboot your Arch-linux running computer early, in case some vital component failed to initialize (a.k.a. e1000e_fsckup_initcpio)

Ok, so this is embarrassingly primitive, but so that I don't loose it (again), I put this small script on github. Maybe someone else having a problem with things not initializing properly on every boot can find the concept useful: I have a computer based on a “DFI LanParty Mini-ITX P55-T36” motherboard with an integrated Intel Gigabit interface. Which works fine so far, but always fails to initialize networking on the first bootup after power-on. This is obviously inconvenient for unattended operation.

To fix this once and for all and reboot the computer early, feel free to use the code at

From Chris’ Miscellanea

Thursday, May 30, 2013

Antlers (May 2013 edition)

I was on vacation again, so here's the obligatory antlers picture. I already posted another one elsewhere, but that was taken with the (a little bit) crappy phone camera and doesn't do the wallpaper and the antlers justice.

From Chris’ Miscellanea

Sunday, May 19, 2013

Wireless on Raspberry π, Power Issues

I'm playing with a Accellerometer/Gyroscope/Magnetometer board (ebay, link probably stale soon), and to have it somewhat mobile, I've connected it to the ole' trusty Raspberry π.

Unfortunately I have problems with a lot of WiFi adapters because of the many fuses inside of the π dropping voltages (starting with 4,5V from my Notebook/USB hub, it goes down to 3,8V on the USB connector). But adding a short wire bridging all those fuses helps ;-).

The dongle used is really old, it's a 

Bus 001 Device 005: ID 07b8:b21d AboCom Systems Inc RT2573

and gets quite warm (correlates well with the high power consumption and hence voltage drop on the fuses), also looses contact with my (just nearby) access point frequently.

[ 2140.585617] ieee80211 phy0: wlan0: No probe response from AP 68:7f:74:5e:42:ff after 500ms, disconnecting.
[ 2140.607093] cfg80211: All devices are disconnected, going to restore regulatory settings
[ 2140.607132] cfg80211: Restoring regulatory settings
[ 2140.607420] cfg80211: Calling CRDA to update world regulatory domain
[ 2141.948125] wlan0: authenticate with 68:7f:74:5e:42:ff
[ 2141.996396] wlan0: send auth to 68:7f:74:5e:42:ff (try 1/3)
[ 2141.998072] wlan0: authenticated
[ 2141.998877] rt73usb 1-1.2:1.0: wlan0: disabling HT due to WEP/TKIP use
[ 2141.998912] rt73usb 1-1.2:1.0: wlan0: disabling HT as WMM/QoS is not supported
[ 2142.035630] wlan0: associate with 68:7f:74:5e:42:ff (try 1/3)
[ 2142.037914] wlan0: RX AssocResp from 68:7f:74:5e:42:ff (capab=0x431 status=0 aid=20)
[ 2142.037943] wlan0: invalid AID value 0x14; bits 15:14 not set
[ 2142.057687] wlan0: associated