TECHSHIP IS A GLOBAL SUPPLIER OF WIRELESS COMPONENTS
This document provides a technical overview of the Telit LE910 V2 Series LGA cellular modules.
This document describes the integration steps of the cellular modules USB endpoints in Linux systems.
How to collect initial diagnostics data and logs for Telit cellular modules needed when requesting Techship technical support?
In order to ease the troubleshooting of technical problems and understand your end-product or application and its usage scenario we ask you to please provide the following information when creating a technical support ticket at: techship.com/technical_support/
Please give a detailed problem description and in what precise circumstances it is present.
Describe the host system:
-Hardware (system board, processor architecture, other peripheral devices...)
-Operating system with detailed versions (E.g. Windows version and build, Linux distribution, kernel version)
-Drivers used and versions (Linux: out-of-tree vendor drivers or in-kernel drivers?)
Details from the cellular module label:
-SKU/BOM or P/N code
For Linux systems, capture terminal logs from commands:
ls -l /dev/serial/by-id
ls -l /sys/bus/usb-serial/devices
The cellular module logs can be acquired by accessing one of the USB enumerated serial (COM) interfaces or physical UART serial interfaces accepting AT commands. In Windows device manager they are generally found as modem infterface or serial and ports interface types).
Send AT commands to module and capture the text output:
Test that you get a OK reply:
Enable AT command echo:
Verbose error reporting:
USB endpoint configuration:
Serial port configuration:
Selected network access techniques:
List network operator info:
Network registration status:
Last serving cell network information:
Current network status:
List APN details:
List Packet switch enable/disable status:
List PDP profiles status:
List default data connection details:
List bearers and IP addresses:
Additional test commands for Telit LM940/LM960:
What Linux kernel modules and configs are commonly used for communicating with cellular modules over their USB interface?
Most cellular modules can be supported in Linux by using som of the in-kernel drivers. The physical data interface to the host Linux system is usually done over USB which enumerates a set of different endpoints/interfaces. A set of serial interfaces for Modem/PPP, AT commands, NMEA location data and chipset debug information are almost always available in all configurations.
In addition some type of network endpoint/interface are also available and exposed. This can vary between manufacturers and chipset vendors and can also commonly be configurable by using USB configuration mode switching or through vendor specific AT commands.
Recommended kernel configurations to enable are listed bellow. Many cellular modules base their Linux support on these modules and drivers. Once included in the kernel build, the USB interfaces will be detected and bound correctly out-of-the-box or after applying source code patches to the driver modules.
Configs for USB serial drivers:
Configs for Modem/PPP support:
Configs for USB network drivers:
Please relate to the Techship product specific web pages for vendor specific Linux integration guides.
Below is a selection of kernel commits relating to cellular module support in Linux kernels:
qmi_wwan: Add support for Fibocom NL678 series
qmi_wwan: Added support for Telit LN940 series
qmi_wwan: Added support for Fibocom NL668 series
USB: serial: option: add support for GosunCn ME3630 RNDIS mode
USB: serial: option: add support for Simcom SIM7500/SIM7600 RNDIS mode
USB: serial: option: add Simcom SIM7500/SIM7600 (MBIM mode)
USB: serial: option: add Fibocom NL678 series
USB: serial: option: add Telit LN940 series
USB: serial: option: add Fibocom NL668 series
USB: serial: option: add GosunCn ZTE WeLink ME3630
qmi_wwan: apply SET_DTR quirk to the SIMCOM shared device ID
If you use any of the listed cellular modules, drivers and specified USB modes in the commits above, ensure that your kernel version already include the patch or apply it to your build.