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I have a new Raspberry Pi that I am trying to run as a local server in my apartment over Wi-Fi. I am using an Edimax Wi-Fi dongle.

When I start the Pi with the keyboard and Wi-Fi dongle both attached, the server starts fine -- wlan0 gets an IP address.

When I start it without the keyboard, wlan0 does not get an IP address. If I then do sudo service networking restart, I then get an IP address again and all is swell.

Interestingly, if HDMI is not attached, it seems to have the same problem.

The problem is that I'd like to be able to start the Pi blind, but it needs manual intervention. I've done a lot of searching, and can't really seem to find anything. Any thoughts on diagnostic steps would be much appreciated.

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  • Do you have it setup for a static IP? – syb0rg Oct 8 '13 at 3:48
  • Yes, it is configured with a static ip. – Kevin Dolan Oct 8 '13 at 3:52
  • And you are running the latest software and firmware? – syb0rg Oct 8 '13 at 3:54
  • To the best of my knowledge, yes. – Kevin Dolan Oct 8 '13 at 4:01
  • are there any wlan-related differences in dmesg/syslog when booting with keyboard and without? have you disabled/uninstalled LXDE or any other X-related desktop software? – lenik Oct 8 '13 at 4:37
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Apparently Current requirements are an issue especially when using a WiFi Adapter such as Edimax 7811UN series along with HDMI. It is advisable to use Power Adapters which provide a current rating of 2 Amperes in order to provide sufficient current to the WiFi adapter and the Pi.

I use Pis and WiFi adapters everyday and I always have to check if the power adapters are of minimum 2 Ampere rating.

Hope it helps.

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Networking issues like this are almost always due to RPi power source problems - specifically, insufficient current available in the RPi's power source. When the RPi boots up, it requires more power than during normal operation. This additional power draw causes a dip in output voltage as seen by the RPi which in turn causes unreliable operation of the RPi. Try a different power source for your RPi.

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  • While this is often true, in this case, it doesn't appear to be the issue, as the Pi works fine with keyboard and HDMI plugged in (greater current drain), but not without (which would mean less current drain). Which would imply that it works when there is a greater current drain, but not when there is less (as less peripherals are plugged in). Indeed this is a strange case. – Greenonline Feb 8 '16 at 4:15

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