Using GL-MiFi

Industrial grade mobile Wifi

Choosing the correct configuration

GL-MiFi is designed for flexbility so when you buy from our shop you can choose configurations.

The most important is that you choose the correct 3G/4G modules that works in your country.

Generally for American, Europe and Asia the modules and bands are different. If you are not in these areas please consult your service provider for more details.

Power it on

When you get the mifi device, You can insert your SIM card. You can also insert a MicroSD card if you want to share its content.

please connect power and press and hold the power button for 3 seconds to power the device on.

You can connect to the MiFi using an Ethernet cable or using WiFi. The default password is goodlife.

Now using a browser, acess to set the device up.

Lan IP

First time setup

The User interface is the same as our other mini routers. You can consult other pages for Mini routers for setting up Internet, wifi and LAN.

Compatible 3g/4g modules

GL-Mifi is compatible with most PCIe 3G/4G modules. We have three modules tested.

To Check if the modules are recognized by the MiFi:

SSH to the board or using serial, and use this command:

ls /dev/ttyUSB*

If the console displays ttyUSB0, ttyUSB1, ttyUSB2, ttyUSB3 and/or ttyUSB4 (as figure shown below), that means GL-MiFi identified the module and we can then configure the MiFi.

Check if the device is supported in QMI mode: ls /dev/cdc-wdm0

For Quectel EC20, and UC20, the port should be used as:

For Huawei ME909s-821, the data port is /dev/ttyUSB0

Name Data Port AT Command Port
Quectel EC20 /dev/ttyUSB3 /dev/ttyUSB2
Quectel UC20 /dev/ttyUSB3 /dev/ttyUSB2
Huawei ME909s-821 /dev/ttyUSB0
Huawei EM770 /dev/ttyUSB2 /dev/ttyUSB0


MiFi expose all the spare GPIOs of AR9331 so it is good for IoT projects. Please check the picture below for GPIO numbers.

Lan IP

Setting up Internet

If you want to connect to the Internet using 3G/4G, 1. Click "Internet" area 2. Click "New connections" 3. Click "3G" tab 4. First, choose region and then choose service provider. The UI will fill the gray field automatically. 5. Please choose the correct device. Consult the above sections for details. 6. Please choose correct service type, UMTS or EVDO 7. If the gray field contains wrong information, e.g. wrong apn, please edit the field and report to us. 8. Click "Submit" button

MiFi setup

In Internet status windows it will show the status of 3G/4G connection.

There are two buttons what you can use in case you have problems with the device.

MiFi setup

AT commands

For UC20/EC20, /dev/ttyUSB2 is for AT commands. First send the commands to the port, then get the output from the port. For example:

echo -e "AT+xxx \r\n" > /dev/ttyUSB2
cat /dev/ttyUSB2

Comgt – a quick tool

There is a build-in tool called “comgt” which you can quickly check if you SIM card is registered or not. This should give the correct output before you set up the apn and start network connection.

root@dominomifi:/# comgt 
Trying list of devices
SIM ready
Waiting for Registration..(120 sec max)
Registered on Home network: "one2free",6
Signal Quality: 14,99

Request International Mobile Equipment Identity

echo -e "AT+GSN\r\n" > /dev/ttyUSB2
cat /dev/ttyUSB2

Correct result:


If you get the similar number, it means that the connection is OK.

Wrong result:

Request SIM’S CCID

echo -e "AT+QCCID\r\n" > /dev/ttyUSB2
cat /dev/ttyUSB2

Correct result:

+QCCID: 89860115851079757018

If you get the similar number, it means that the connection of SIM-card is OK.

Wrong result:

Request IMSI

echo -e "AT+CIMI\r\n" > /dev/ttyUSB2
cat /dev/ttyUSB2

Correct result:


Wrong result:


Check Network Registration

echo -e "AT+CREG?\r\n" > /dev/ttyUSB2
cat /dev/ttyUSB2

Correct result:

+CREG: 0,1

If you get the similar result, it means that your SIM-card has registered in telecom operators

Wrong result:


Signal Quality Report

echo -e "AT+CSQ \r\n" > /dev/ttyUSB2
cat /dev/ttyUSB2

Correct result:

 +CSQ: 21,99

This first number—“21” is the result. We usually get the value number is 18~23.

Wrong result:


Query The Currently Selected Network Operator

echo -e "AT+COPS?\r\n" > /dev/ttyUSB2
cat /dev/ttyUSB2

Correct result:


The currently network operator is ChinaUnicom

Wrong result:


Choose network mode

set modem to only LTE

echo -e "AT+QCFG=\"nwscanmode\",3,1" > /dev/ttyUSB2 

set back to auto

echo -e "AT+QCFG=\"nwscanmode\",0,1" > /dev/ttyUSB2


You can reset the modem using AT command. The modem will be disconnected and connected again.

echo -e “AT+QRST=1,0” > /dev/ttyUSB2

GPS Location

This only applies to Quectel UC20 3g module, which has GPS built in.

Initialization Command:

echo -e "AT+QGPSCFG=\"outport\",\"usbnmea\" \r\n" > /dev/ttyUSB2  
echo -e "AT+QGPSCFG=\"nmeasrc\",1 \r\n" > /dev/ttyUSB2
echo -e "AT+QGPSCFG=\"gpsnmeatype\",1 \r\n" > /dev/ttyUSB2
echo -e "AT+QGPSCFG=\"glonassnmeatype\",4 \r\n" > /dev/ttyUSB2
echo -e "AT+QGPSCFG=\"glonassenable\",0 \r\n" > /dev/ttyUSB2
echo -e "AT+QGPSCFG=\"odpcontrol\",0 \r\n" > /dev/ttyUSB2
echo -e "AT+QGPSCFG=\"dpoenable\",0 \r\n" > /dev/ttyUSB2
echo -e "AT+QGPS=1 \r\n" > /dev/ttyUSB2

Location Command:

echo -e "AT+QGPSLOC? \r\n" > /dev/ttyUSB2
cat  /dev/ttyUSB2 

Module Closure:

echo -e "AT+QGPSEND \r\n" > /dev/ttyUSB2

If you want to know more, please refer Quectel_UC20_AT_Commands_Manual_V1.5.pdf which you should be able to download if you bought GL-MiFi.

Working with QMI mode

Note: QMI mode is supprted from firmware v2.23-6.

If the firmware is commpiled with QMI driver, you will find /dev/cdc-wdm0 in the Linux system.

For unknown reason, UC20 seems not work in this mode.


From firmware V2.23-6, EC20 is always using QMI mode when you config it in the UI. If you want to configure manually, check /etc/config/network

config interface 'modem'
    option proto 'wwan'
    option ifname 'wwan0'

You need to do a network restart

/etc/init.d/network retart


Check connection status

root@OpenWrt:~# uqmi -d /dev/cdc-wdm0 --get-data-status

Get signal info

root@OpenWrt:~# uqmi -d /dev/cdc-wdm0 --get-signal-info
        "type": "lte",
        "rssi": -71,
        "rsrq": -9,
        "rsrp": -94,
        "snr": 70

To start the Internet connection, replace “apn” with your real apn

uqmi -d /dev/cdc-wdm0 --start-network apn  --autoconnect

Then you will see you have wwan0 in your ifconfig

root@domino:/# ifconfig wwan0
wwan0     Link encap:Ethernet  HWaddr 9A:02:75:A0:CA:59  
          inet6 addr: fe80::9802:75ff:fea0:ca59/64 Scope:Link
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:254 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:82077 (80.1 KiB)

AT commands

You can also use low level AT commands to start the Internet.

The apn, username and password should be sent in the following format:

AT+QICSGP=1,1,"apn" [,"username","password" [,]]]

For example, my apn is “pccw”, I am using the following command.

cat /dev/ttyUSB2 &
echo -en "AT+QICSGP=1,1,\"pccw\",\"\",\"\",0\r\n" > /dev/ttyUSB2
echo -en "AT+QCFG=\"rmnet/autoconnect\",1,0\r\n" > /dev/ttyUSB2

You need to do a RESET to make the changes take effect according to Quectel manual.

echo -e "AT+QRST=1,0\r\n" > /dev/ttyUSB2

Compile your firmware

coming later


No ttyUSB0~ttyUSB4

This generally means the driver is not installed or the module is not recognized. You may need to check the connections of the module.

Field: [option_instat_callback: error -2] appears after startup

For some complicated reasons: Bad contact of SIM Card. No antenna inserted. Wrong operator parameters. No network. Data interface (ttyUSBx) configured incorrectly. When this happens: 1. Check connection 2. Connect antennas 3. Correct network settings 4. After you have done the above, try to restart network by execute /etc/init.d/network restart . If the error still exists, try to unplug the power and plug the power again. Simply reboot the device without unplug the device may not help.