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mPCIe modems

RB350 has one PCI Express Mini Card connector for 3G/LTE modems. The mPCIe slot supports USB 2.0 and a Mini-SIM card. It is also worth mentioning that the mPCIe card is powered by the built-in UPS. The GSM LED indicates the connection status. The power supply of the mPCIe card is controlled by GPIO. A U.FL to SMA female connector cable for an external antenna is included for easy connection.

Linux supports many mPCIe modems, so usually, no additional drivers are needed. mPCIe modems usually provide a few serial ports (appears as /dev/ttyACMx or /dev/ttyUSBx) for communicating with the modem via AT commands. For example, for the F3507g modem:

$ ls /dev/ttyAC* 
/dev/ttyACM0 /dev/ttyACM1 /dev/ttyACM2

Power supply control

The mPCIe power supply is controlled using GPIO1.

Setting GPIO1 to 0 turns on the power supply.

$ gpio write 1 0

GPIO1 = 1 turns off the power supply.

$ gpio write 1 1

Example AT-Commands

Accessing the modem with picocom: 

$ apt-get install -y picocom 
$ picocom -b 115200 /dev/ttyACM0

Example AT commands: 

at+gmi 
Dell 
OK 
at+gmm 
D5530 
OK 
at+cpin? 
+CPIN: READY 
OK 
at+cfun=1 
OK 
at+csq 
+CSQ: 17,99 
OK 
at+cfun=4 
OK

To exit, use Ctrl-a, Ctrl-x.

Connecting to the net

There are a few ways to connect to the internet. The first method is to use the CDC Ethernet interface. Another method is to use the pppd daemon on one of the serial ports (/dev/ttyACM*). To check the possible way you can use command:

$ for n in `ls /sys/class/*/*{ACM,wdm,wwan}*/device/interface`;do echo $(echo $n|awk -F '/' '{print $5}') : $(cat $n);done

For example F3507g modem returns: 

wwan0 : Dell Wireless 5530 HSPA Mobile Broadband Minicard NetworkAdapter 
ttyACM0 : Dell Wireless 5530 HSPA Mobile Broadband Minicard Modem 
ttyACM1 : Dell Wireless 5530 HSPA Mobile Broadband Minicard Modem 2 
ttyACM2 : Dell Wireless 5530 HSPA Mobile Broadband Minicard GPS Port 
cdc-wdm0 : Dell Wireless 5530 HSPA Mobile Broadband Minicard 
cdc-wdm1 : Dell Wireless 5530 HSPA Mobile Broadband Minicard PC SC Port
As you can see, both methods are available in this case.

Connecting to the net via CDC Ethernet interface

First, create a script: 

$ nano /etc/chatscripts/3g.on

Example configuration for the F3507g modem: 

ABORT BUSY
ABORT 'NO CARRIER'
ABORT ERROR
TIMEOUT 30
'' AT+CFUN=1 PACSP0
AT+CPIN? READY \c OK
AT+CGDCONT=1,"IP","virgin-internet" OK
\d\d\d\d\d\d\dAT*ENAP=1,1 OK
Example configuration for the F3607gw modem: 
ABORT BUSY
ABORT 'NO CARRIER'
ABORT ERROR
TIMEOUT 30
'' AT+CFUN=1 OK
AT+CPIN? READY \c OK
AT+CGDCONT=1,"IP","virgin-internet" OK
\d\d\d\d\d\d\dAT*ENAP=1,1 OK

Replace "virgin-internet" with your actual APN. Then run this command: 

$ /usr/sbin/chat -V -v -f /etc/chatscripts/3g.on >/dev/ttyACM0 </dev/ttyACM0

After that, the GSM LED should turn on. Launch dhclient:

$ dhclient wwan0

The connection is ready:

$ ifconfig wwan0

wwan0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 
inet 10.203.38.218 netmask 255.255.255.248 broadcast 10.203.38.223 
ether 02:80:37:ec:02:00 txqueuelen 1000 (Ethernet) 
RX packets 33 bytes 15553 (15.1 KiB) 
RX errors 0 dropped 0 overruns 0 frame 0 
TX packets 35 bytes 3438 (3.3 KiB) 
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

Script to turn off the connection: 

$ nano /etc/chatscripts/3g.off

The content of the script: 

ABORT ERROR 
TIMEOUT 5 
'' AT+CFUN=4 OK

Running the script: 

$ /usr/sbin/chat -V -v -f /etc/chatscripts/3g.off >/dev/ttyACM0 </dev/ttyACM0

The GSM LED should turn off.

Connecting to the net via pppd

For the pppd, the easiest way is to use wvdial.

$ apt-get install wvdial

Next step is edit config file /etc/wvdial.conf

$ nano /etc/wvdial.conf

Example config for F3507g modem:

[Dialer on]

Modem = /dev/ttyACM0 Init1 = AT+CFUN=1

[Dialer off]

Modem = /dev/ttyACM0 Init1 = AT+CFUN=4

[Dialer connect]

New PPPD = yes Stupid Mode = 1 Modem Type = USB Modem Modem = /dev/ttyACM0 Init1 = AT Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 Init3 = AT+CGDCONT=1,"IP","virgin-internet" Baud = 460800 ISDN = 0 Phone = *99# Password = { } Username = { }

You have to check a manual of your modem and change accordingly Init1 command in sections [Dialer on] and [Dialer off]. Replace "virgin-internet" with your APN. To turn on module use command:

$ wvdial on

the GSM LED should turn off. To connect use command:

$ wvdial connect &

If everything goes correctly, you should see a new connection:

$ ifconfig ppp0

ppp0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500 
inet 10.201.28.240 netmask 255.255.255.255 destination 10.64.64.64 
ppp txqueuelen 3 (Point-to-Point Protocol) 
RX packets 4 bytes 58 (58.0 B) 
RX errors 0 dropped 0 overruns 0 frame 0 
TX packets 5 bytes 85 (85.0 B) 
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

The connection is ready.

SMS with gammu

Install gammu: 

$ apt-get install gammu gammu-config

Configuration: 

"port=/dev/ttyACM0"
"connection=at"

Example commands: 

$ gammu --identify
$ echo "Test" | gammu sendsms TEXT _destination_number
$ gammu getallsms