If the current 4gdong001 firmware is functional, extract it first:

dd if=/dev/ttyUSB0 of=backup_4gdong001_old.bin

(Adjust for your specific /dev/ node.)

Before manipulating firmware, one must understand the hardware. The 4gdong001 is typically a compact USB dongle or embedded module designed to add 4G LTE (Long-Term Evolution) connectivity to devices like routers, single-board computers (Raspberry Pi, Orange Pi), or industrial controllers. It often utilizes chipsets from major manufacturers like Qualcomm, ASR (Altair), or RDA.

These dongles are prized for their low power consumption and support for global LTE bands. However, without the correct firmware, the device is essentially a brick. The firmware controls:

If you are uncomfortable with low-level flashing, consider using a firmware-over-the-air (FOTA) capable dongle that supports secure, remote updates. Otherwise, treat 4gdong001 firmware updates like brain surgery—triple-check every step.

Run the following in your terminal:

lsusb -v | grep -A 5 "4gdong001"

Then, using a serial terminal (minicom or screen) on the correct /dev/ttyUSB port, type:

ATI

The response (e.g., Revision: 4gdong001_V2.1.8) tells you the exact firmware.