4G Module

Check if the EC20 4G module kit has been loaded.

   #The following 4 USB interfaces will appear after successful loading
   ls /dev/ttyUSB*
   /dev/ttyUSB0  /dev/ttyUSB1  /dev/ttyUSB2  /dev/ttyUSB3

If the load is not successful, check that the kernel has the following
configuration turned on.

   Symbol: USB_SERIAL_OPTION [=y]
   Type  : tristate
   Prompt: USB driver for GSM and CDMA modems
   Location:
   	-> Device Drivers
   		-> USB support (USB_SUPPORT [=y]) 
   			-> USB Serial Converter support (USB_SERIAL [=y]) 
   Defined at drivers/usb/serial/Kconfig:558
   Depends on: USB_SUPPORT [=y] && USB [=y] && USB_SERIAL [=y]
   Selects: USB_SERIAL_WWAN [=y]

If the 4G module cannot be connected to the network, please check
whether the following configuration is turned on in the kernel.

   CONFIG_USB_USBNET
   CONFIG_USB_NET_QMI_WWAN

Check whether the EC20 4G network card exists.

   ifconfig wwan0

How to use EC20 4G module to access the Internet with a SIM card

   # Download the ec20-armhf.tar.gz compressed package from the data download interface and copy it to the development board to decompress
   # Need to replace the folder /ec20-armhf/usr/share/udhcpc/default.script with the system's /usr/share/udhcpc/default.script
   # The results are as follows:
   [root@RV1126_RV1109:/userdata/ec20-armhf]# quectel-CM &
   [root@RV1126_RV1109:/userdata/ec20-armhf]# [04-20_14:27:04:405] Quectel_Linux_ConnectManager_SR01A01V21
   [04-20_14:27:04:406] quectel-CM profile[1] = (null)/(null)/(null)/0, pincode = (null)
   [04-20_14:27:04:407] Find qmichannel = /dev/cdc-wdm0
   [04-20_14:27:04:407] Find usbnet_adapter = wwan0
   [04-20_14:27:04:422] cdc_wdm_fd = 7
   [04-20_14:27:05:422] QmiThreadSendQMITimeout pthread_cond_timeout_np=110, errno: 2 (No such file or directory)
   [04-20_14:27:06:520] Get clientWDS = 19
   [04-20_14:27:06:552] Get clientDMS = 1
   [04-20_14:27:06:584] Get clientNAS = 3
   [04-20_14:27:06:617] Get clientUIM = 1
   [04-20_14:27:06:648] Get clientWDA = 1
   [04-20_14:27:06:681] requestBaseBandVersion EC20CFDR02A07M4G  1  [Nov 10 2016 17:00:00]
   [04-20_14:27:06:743] requestGetSIMStatus SIMStatus: SIM_READY
   [04-20_14:27:06:777] requestGetProfile[1] cmnet///0
   [04-20_14:27:06:808] requestRegistrationState2 MCC: 460, MNC: 0, PS: Attached, DataCap: LTE
   [04-20_14:27:06:839] requestQueryDataCall ConnectionStatus: DISCONNECTED
   [04-20_14:27:06:904] requestRegistrationState2 MCC: 460, MNC: 0, PS: Attached, DataCap: LTE
   [04-20_14:27:07:447] requestSetupDataCall WdsConnectionIPv4Handle: 0x87205120
   [04-20_14:27:07:513] requestQueryDataCall ConnectionStatus: CONNECTED
   udhcpc: started, v1.27.2
   Failed to kill daemon: No such file or directory
   udhcpc: sending discover
   udhcpc: sending select for 10.154.101.71
   udhcpc: lease of 10.154.101.71 obtained, lease time 7200
   Failed to kill daemon: No such file or directory
   [04-20_14:27:07:729] deleting routers
   [04-20_14:27:07:772] adding dns 221.179.38.7
   [04-20_14:27:07:772] adding dns 120.196.165.7
   [root@RV1126_RV1109:/userdata/ec20-armhf]#ifconfig wwan0
   wwan0     Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  
             inet addr:10.154.101.71  P-t-P:10.154.101.71  Mask:255.255.255.240
             UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
             RX packets:2 errors:0 dropped:0 overruns:0 frame:0
             TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:1000
             RX bytes:612 (612.0 B)  TX bytes:656 (656.0 B)