Wifi does not work

A list of common Wifi issues #

• Wrong password.
• Wrong SSID.
• Wifi adapter does not support Wifi channel selected on Wifi router.
• USB Wifi adapter and built-in Wifi adapter both trying to run at the same time.
• Some audio cards interfere with Raspberry Pi built-in Wifi adapters.
• Wifi drivers are gradually changing from “wext” to “nl80211” standard.
• Kernel upgrades can break USB Wifi drivers. Unfortunately, we can not test all USB Wifi drivers prior to each piCorePlayer release.

Diagnostics #

• Check the Wifi MAC and IP addresses have been set by looking at [Wifi settings] > “Wifi information”. For example:

	Wifi MAC: dc:a6:32:00:2a:4d
	Wifi IP: 192.168.1.110

• Check wifi diagnostics information by clicking on [Wifi settings] > “Set Wifi configuration” > [Dignostics].

• Check the boot log by clicking on [Main Page] > [Diagnostics] > [Logs] > “Boot” .

Extract from the boot log:

Starting WiFi on wlan0...
udhcpc: started, v1.33.0
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending select for 192.168.1.104
udhcpc: lease of 192.168.1.104 obtained, lease time 86400
deleting routers
route: SIOCDELRT: No such process
adding dns 192.168.1.50
adding dns 0.0.0.0
Starting wifi... Done.

You can see from the above that an IP address has successfully been obtained.

Sometimes the udhcpc discovery process is forked to the background. This will cause a delay in the “awaiting for network” in the boot process.

Starting WiFi on wlan0...
udhcpc: started, v1.33.0
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending discover
udhcpc: no lease, forking to background
Starting WiFi... Done.

Note:

• multiple udhcpc: sending discover indicates DHCP is looking for an IP address
• udhcpc: lease of 192.168.1.104 obtained, lease time 86400 indicates DHCP has allocated an IP address
• adding dns 192.168.1.50 indicates a dns server has been set

More information #

• Setup Wifi
• Setup Wifi without ethernet
• Wifi does not work
• Example wpa_supplicant configuration file
• WPA Supplicant
• The Short List - Superstar USB WiFi Adapters for Linux
• USB wifi adapters - historical information
• Utility for compiling out of tree kernel modules for pCP Kernels