Cannot generate wwan interface with the 3G/4G base shield and huawei modem

I followed the tutorial for the shield in order to generate the wwan interface but it didn’t work on the RPi. because of that, I directly wrote AT commands in order to connect to the network but the wwan interface still does not appear. The modem is huawi me909u521. How could I have the wwan interface to connect to the network?

Hi @nfernandez,

After connecting the micro-USB cable to the rpi, could you share the output of the following commands:
dmesg | grep tty
lsusb -t

Hi @ensar,

dmesg | grep tty response:

[ 0.000000] Kernel command line: coherent_pool=1M 8250.nr_uarts=0 bcm2708_fb.fbwidth=656 bcm2708_fb.fbheight=
416 bcm2708_fb.fbswap=1 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000 dwc_otg.lpm_enable=0 console=ttyS
0,115200 console=tty1 root=PARTUUID=8810a729-02 rootfstype=ext4 elevator=deadline rootwait ip=19 quiet splash plymouth.ignore-serial-consoles
[ 0.000301] console [tty1] enabled
[ 0.729871] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 81, base_baud = 0) is a PL011 rev2
[ 7.196597] systemd[1]: Created slice system-getty.slice.
[ 8.821540] cdc_acm 1-1.1.3:1.0: ttyACM0: USB ACM device
[ 9.282683] usb 1-1.3: GSM modem (1-port) converter now attached to ttyUSB0
[ 9.283947] usb 1-1.3: GSM modem (1-port) converter now attached to ttyUSB1
[ 9.287131] usb 1-1.3: GSM modem (1-port) converter now attached to ttyUSB2
[ 9.289597] usb 1-1.3: GSM modem (1-port) converter now attached to ttyUSB3

lsusb -t reponse:
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 3, If 0, Class=Hub, Driver=hub/3p, 480M
|__ Port 3: Dev 5, If 0, Class=Communications, Driver=cdc_acm, 12M
|__ Port 3: Dev 5, If 1, Class=CDC Data, Driver=cdc_acm, 12M
|__ Port 1: Dev 6, If 0, Class=Vendor Specific Class, Driver=lan78xx, 480M
|__ Port 3: Dev 4, If 0, Class=Communications, Driver=, 480M
|__ Port 3: Dev 4, If 1, Class=CDC Data, Driver=, 480M
|__ Port 3: Dev 4, If 2, Class=Vendor Specific Class, Driver=option, 480M
|__ Port 3: Dev 4, If 3, Class=Vendor Specific Class, Driver=option, 480M
|__ Port 3: Dev 4, If 4, Class=Vendor Specific Class, Driver=option, 480M
|__ Port 3: Dev 4, If 5, Class=Vendor Specific Class, Driver=option, 480M

Hi @nfernandez,

Your module supports CDC-ECM interface. Please see ECM application scenarios in the module application guide.

HI @ensar,

I did the steps for ECM:


And by doing AT^NDISSTATQRY? I know that the connection is set up: ^NDISSTATQRY: 1,“IPV4”,0,0,“IPV6”

But not obtaining an interface with an IP.

Hi @nfernandez,

The process of obtaining the IP address:

  1. After the host application sending AT^NDISDUP command to launch or terminal
    the ECM connection, Huawei module will report the ^NDISSTAT command to
    indicate the connection state.
  2. The host application can get the connection state from ^NDISSTAT report. If the
    connection state is updated, the host application should launch the DHCP client
    to update the ECM IP address or disable the ECM.
  3. The host application also can send AT command AT^NDISSTATQRY? to query
    the current ECM connection state, and determine to update or disable the ECM
    by the DHCP client.

Note: AT^NDISDUP command should be sent by PCUI port.

Also, check your APN’s name.

hi @ensar

Yes, I did exactly this and where apn in the previous command I put my own one. Becuase of that, following the steps in the application guide, I don’t understand why the interface is not appearing and obtaining an IP.

Please help to provide the return value of the following AT commands.


Hi @ensar

Hereafter the response that I receive form the AT commands:


+CFUN: 1


+CREG: 1,1

+COPS: (2,“vodafone ES”,“vodafone ES”,“21401”,7),(1,“vodafone”,“voda ES”,“21401”,2),(3,“YOIGO”,“YOIGO”,“21404”,7),(3,“Movistar”,“Movistar”,“21407”,2),(3,“Movistar”,“Movistar”,“21407”,7),(3,“Orange”,“Orange”,“21403”,2),(3,“Orange”,“Orange”,"2)

^HCSQ: “LTE”,36,26,137,20