Connect ModuCop to Internet using Wifi


In this section, you will use ModuCop’s integrated Wifi module to connect with the internet.

You will:

  • Scan for Wifi networks
  • Connect to a Wifi access point
  • Check Internet connection

You will use Linux Networkmanager and its command line tool nmcli.


What you need:

  • ssh access from your development PC to ModuCop’s Linux Terminal
  • At least one Wifi Antenna
  • Wifi Access Point that provides Internet connection
  • Password for your Wifi Access point

Step 1: Attach Wifi Antenna

Attach Wifi antenna to ModuCop’s antenna connectors labelled WLAN1 and WLAN2. One antenna is enough, a second antenna can improve Wifi quality.

Step 2: Scan for Wifi Access Points

Run the command below to see the available wifi access points. Wait for the output message.

The access point that should be used for your Internet connection shall appear in the list:

# nmcli device wifi list ifname mlan0
IN-USE  BSSID              SSID                         MODE   CHAN  RATE        SIGNAL  BARS  SECURITY
        46:4E:6D:DB:C2:97  Ci4Rail-Guest                Infra  1     260 Mbit/s  100     ****  WPA2
        44:4E:6D:DB:C2:97  Ci4Rail-Office               Infra  1     260 Mbit/s  100     ****  WPA2
        02:A0:57:2A:DD:62  INTERN                       Infra  6     130 Mbit/s  32      **    WPA2

Step 3: Connect With Your Access Point

Now connect to your access point using the SSID of the access point (Ci4Rail-Office in this example) and the corresponding password:

# nmcli -a device wifi connect Ci4Rail-Office
Password: *************
Device 'mlan0' successfully activated with 'a881a567-c87b-4fec-add1-a08360bf99b8'.

Verify the IP address you have received from the DHCP server inside the Wifi access point:

nmcli will show you all known network interfaces. Just look at the mlan0 interface:

# nmcli
mlan0: connected to Ci4Rail-Office
        "Marvell Wi-Fi"
        wifi (mwifiex_sdio), D8:C0:A6:5F:9B:63, hw, mtu 1500
        inet4 <YOUR-IP>
        route4 <YOUR-NET>
        inet6 <YOUR-IPV6>
        route6 fe80::/64
        route6 ff00::/8

Please record the assigned IP address in <YOUR-IP>. You’ll use it later in step 5.

NOTE: The connection settings you have entered are stored on ModuCop’s internal disk. So, when you restart your ModuCop, it will automatically re-connect to your Wifi access point.

Step 4: Verify Internet Connection

Now try to ping a server on the Internet. To ensure that you ping over Wifi, specify the Wifi device with the -I option. This ensures that the ping uses the Wifi interface and not your local Ethernet for the Internet access.

root@moducop-cpu01:~# ping -I mlan0 -c 4

You should see a result like this:

PING ( 56 data bytes
64 bytes from seq=0 ttl=55 time=81.814 ms
64 bytes from seq=1 ttl=55 time=104.794 ms
64 bytes from seq=2 ttl=55 time=128.140 ms
64 bytes from seq=3 ttl=55 time=48.950 ms

--- ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 48.950/90.924/128.140 ms

Step 5: Get Rid of Ethernet

Now, as you have a wifi connection, you may get rid of the Ethernet cable you have used to configure ModuCop. However, if you want to access ModuCop’s Linux terminal later from your development PC, your development PC must also be in the access point’s Wifi network.

Now Disconnect your Ethernet Cable.

On your development PC, start a new ssh session, but now enter ModuCop’s IP address on the Wifi network, you have noted in step 3.

You should be able to login as root with the password you assigned in this step