Using the OptConnect ema Modem with Nitrogen8M

Published on November 4, 2020

Hardware Installation
Software Installation
Testing whether the system recognizes the modem
Viewing the modem status in OptConnect Summit Portal
More information on OptConnect ema

We are pleased to announce support for the OptConnect ema Smart Embedded Modem on our Nitrogen8M board! We will discuss how to connect the modem via USB to the Nitrogen8M using a mPCIe adapter card, as well as instructions on how to do some basic testing of the modem. Once ema is connected, you get an enterprise grade, fully-managed connection from OptConnect’s award winning service. More information on the modem can be found here.

Hardware Installation

As mentioned, the modem connects via USB using this mPCIe adapter. The connection to the Nitrogen8M is shown below:

Software Installation

This testing was done with our latest yocto image found here.

Testing whether the system recognizes the modem

The modem will be recognized as a USB device under Linux. You can check the presence of the modem using lsusb:

root@nitrogen8m:~# lsusb
Bus 002 Device 002: ID 045b:0210 Hitachi, Ltd 
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 006: ID 1bc7:0036 Telit Wireless Solutions 
Bus 001 Device 005: ID 10c4:ea70 Silicon Labs CP2105 Dual UART Bridge
Bus 001 Device 004: ID 0424:2412 Microchip Technology, Inc. (formerly SMSC) 
Bus 001 Device 002: ID 045b:0209 Hitachi, Ltd 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

As you can see, the Nitrogen8M recognizes the Telit modem (1bc7:0036).Now that we validated the modem is recognized as a usb device, you can validate that it is detected by modemmanager:

root@nitrogen8m:~# mmcli -L
/org/freedesktop/ModemManager1/Modem/0 [Telit] LE910-NA V2

And you can see more details of the modem with mmcli -m:

root@nitrogen8m:~# mmcli -m 0
--------------------------------
General | dbus path: /org/freedesktop/ModemManager1/Modem/0
| device id: 9eeb9dfa3d73e64418d4257a000cdfe4c207c4d1
--------------------------------
Hardware | manufacturer: Telit
| model: LE910-NA V2
| firmware revision: 20.00.506
| supported: gsm-umts, lte
| current: gsm-umts, lte
| equipment id: 358148062963801
-------------------------------
System | device: /sys/devices/platform/soc@0/38200000.usb/xhci-hcd.0.auto/usb1/1-1/1-1.4/1-1.4.2
| drivers: cdc_acm, cdc_ncm
| plugin: Telit
| primary port: ttyACM0
| ports: ttyACM1 (unknown), ttyACM3 (unknown), ttyACM5 (unknown), 
| wwan0 (net), ttyACM2 (unknown), ttyACM4 (unknown), ttyACM0 (at)
--------------------------------
Status | unlock retries: sim-pin (3), sim-puk (10), sim-pin2 (3), sim-puk2 (10)
| state: registered
| power state: on
| access tech: lte
| signal quality: 71% (recent)
--------------------------------
Modes | supported: allowed: 3g; preferred: none
| allowed: 4g; preferred: none
| allowed: 3g, 4g; preferred: none
| current: allowed: 3g, 4g; preferred: none
--------------------------------
Bands | supported: utran-5, utran-2, eutran-2, eutran-4, eutran-5, eutran-12, 
| eutran-13, eutran-17
| current: utran-2, eutran-2
--------------------------------
IP | supported: ipv4, ipv6, ipv4v6
--------------------------------
3GPP | imei: 358148062963801
| operator id: 310410
| operator name: AT&T
| registration: home
--------------------------------
3GPP EPS | ue mode of operation: csps-1
--------------------------------
SIM | dbus path: /org/freedesktop/ModemManager1/SIM/0

We can also start a screen serial console application to communicate with the modem on ttyACM0 (primary AT port of the modem, as shown above).

root@nitrogen8m:~# screen /dev/ttyACM0 115200

Now you get an empty console screen. If local command echo is not set, then type ATE1 to the modem blindly, which will enable command echo. You can now talk to the modem via AT commands found in this document. For example, we can get the modem serial number:

AT+GSN
0000675966
OK

Viewing the modem status in OptConnect Summit Portal

Once you purchase a modem, you can call OptConnect with an ema serial number and they will set you up with an account. The account can also be set up at the same time an order is placed. Once you have the modem linked with an account, you can login to the portal and view your device:We can see the device online and view its status: