Although the Raspberry Pi Model B comes with built-in 100Mbps wired Ethernet, it can also use WiFi via a USB dongle. The Model A doesn’t come with Ethernet at all, so using a WiFi adapter is a good way to get networking on that model. In both cases, simply plugging in a supported USB dongle and doing a simple bit of configuration will give your Pi access to wireless.
You can get yourself a USB adapter for less than $10 but it is important to buy one which is supported by the Raspberry Pi and Linux. For this tutorial, I will be using a dongle based on the Realtek RTL8188CUS chipset. The Realtek chipset is supported by Raspbian out-of-the-box and no additional configuration is needed for it to be recognized during boot.
The RPi USB Wi-Fi Adapters page has a comprehensive list of supported wireless adapters. If you are considering buying a dongle, you should check that page for compatibility.
Plug in the USB adapter and boot your Raspberry Pi. There are several ways to check if the adapter has been recognized. The easiest is to type:
You should see a listing for
eth0 – the built-in wired Ethernet port; for
lo – the loop back device; and
wlan0 – the wireless adapter.
Alternatively you can list the current USB devices attached to the Pi using:
The list should contain your wireless dongle. On my setup, the list shows a “Realtek Semiconductor Corp. RTL8188CUS 802.11n WLAN Adapter”.
Desktop set up
If you are using the desktop on Raspbian than connecting to a wireless network is quite easy. Double click the “WiFi Config” icon on the desktop to start the wireless configuration program. The “Adapter:” field will show your USB dongle (i.e. wlan0) and the “Network:” field will be empty (unless you have previously configured a wireless network). Click the “Scan” button. Now click “Scan” on the “Scan results” window. A list of the available wireless networks will be shown along with their signal strengths etc. To connect to one of the listed networks, double click on the SSID.
On the connection window, verify the “Authentication” and “Encryption” fields and enter the password in the “PSK” field. Now Click “Add”. Close the “Scan results” window. The configuration program will automatically connect to the newly configured network.
You can add multiple networks by repeating the same steps. You can select the desired network using the “Network:” drop down list. You can also connect and disconnect using the relevant buttons. You can use the “Managed Networks” tab to edit and remove networks.
Command line set up
If you aren’t using the desktop then the WiFi can be configured using the command line. Raspbian should come with all the correct packages pre-installed but if any of the commands or files mentioned below aren’t available, then run this command to install them:
The general network settings are configured in “/etc/network/interfaces” while the Wi-Fi details are set in the “/etc/wpa_supplicant/wpa_supplicant.conf” file. First edit the “interfaces” file:
Ensure that the section about
wlan0 (typically found at the end of the file) reads as follows:
If there are difference then change them to accordingly. Don’t alter any of the lines about the
lo adapter or the
eth0 adapter. Press “CTRL + X” to exit nano (press Y and then press ENTER when prompted).
To get a list of the currently available wireless networks, use the
If there is too much information, use
grep to find the fields you need. For example to see just the ESSIDs, use:
Pick a network and add the network authentication information in the “wpa_supplicant.conf” file:
The first two lines should already read:
Now add the following:
If your router is configured using WEP for encryption then the network information will look like this:
For those of you familiar with advanced WiFi configurations, the network information can also include the following fields:
- proto – Protocol type can be: RSN (for WP2) and WPA (for WPA1).
- pairwise – CCMP or TKIP (for WPA2 or WPA1).
- auth_alg – authentication algorithm, can be OPEN for both WPA1/WPA2 and less commonly SHARED or LEAP.
Press “CTRL + X” to exit nano and save the file, press Y and then press ENTER when prompted. Finally reboot your Pi:
You can check the status of the wireless connection using
ifconfig (to see if
wlan0 has acquired an IP address) and
iwconfig to check which network the wireless adapter is using.
If you have any questions about wireless on the Raspberry Pi, please ask them in the comments and we will see if we can help.