Advanced Configuration for 3G / 4G / LTE modems

Last updated on October 21st, 2024

Table of Contents

Most modems will work out of the box just by plugging in your modem and configuring any required information (such as APN, username, password, and sim-card PIN).

Nevertheless, there are cases where the system might not recognize your modem as a modem. This guide is for advanced (Linux) users only. Do not hesitate to contact us if your modem is not working out of the box.

USB mode-switching

Most USB modems usually appear as a CD-ROM or a Mass Storage Device so that any required software can be included with the USB module itself. Usually, after the software installation, the modem switches to modem mode, and the system recognizes it as a USB modem device. This process is called USB mode switching. On Raspbian (the Yodeck SD card image is based on Raspbian), this is internally handled by the udev manager and usb_modeswitch package. If a modem has been mode-switched, it should appear in the system under the /dev directory as ttyUSB0, ttyUSB1, etc., or as cdc-wdm0.

Some devices may not automatically switch to the correct USB mode after plugging in. This may happen for newer devices or for devices that are mode-switched to the wrong USB mode. Using the Advanced Configuration field, you can provide a usb_modeswitch configuration for your specific device.

For example:

[[12d1:1f01]] TargetVendor=0x12d1 TargetProductList="1442" MessageContent="55534243123456780000000000000011062000000100000000000000000000"

The above configuration will switch the recognized USB device with ID 12d1:1f01 to the target device with ID 12d1:1442 using the MessageContent.

Getting the ID of the unswitched device

Get the ID of the device before any mode switching is required to search the Internet for the correct message content for your device.

SSH to the player (Connecting to the player via SSH)
Make sure the modem is not plugged in
Run sudo systemctl stop udev
Plugin your modem
Run lsusb to get a list of the USB devices that are connected and their IDs. You should be able to identify your device and get its ID.
Search for usb_modeswitch and the device ID to find a working usb_modeswitch configuration.
Reboot the player
Create the configuration in the above format

Udev rule

If the un-switched device is not switched, even if a custom mode-switching configuration exists, it is probably not matched by any udev rule, so the mode-switching is not triggered.

If a custom udev rule is required to match the un-switched device, it can be provided like this:

[[udev]] ATTR{idVendor}=="12d1", ATTR{idProduct}=="1f01", RUN+="usb_modeswitch '%b/%k'"

Custom Network Manager connection profile

The player will use the Network Manager to handle the modem connection. The default configuration of the Network Manager is used for the modem connection profile. If a connection requires any extra special configuration, there is the option to provide the exact Network Manager configuration using the Advanced Configuration field. You can provide the configuration for the connection like this:

[[network]] [connection] id=custom uuid=74dbed2d-5152-4928-82e1-ad41669f3be5 type=gsm

[gsm] number=*99# pin=1234 apn=apn.example.com

[ipv6] method=auto

[ipv4] method=auto

The connection name must always be “custom” as the player uses this name internally.

You can find more about the available configuration options for the connection profile in the following URLs:

Connection Settings
GSM Settings

Complete Configuration

You can combine both configurations (USB mode-switching and custom Network Manager configuration) into a single configuration that can be used directly in the Advanced Configuration field.