4UDEG25G 4G LTE USB Dongle with Quectel EG25-G | GPS, SMS via AT, No USB Audio

FAQs: 4G LTE USB Dongle with EG25-G LCC Module

What network bands does the 4UDEG25G support? Is it suitable for global LTE networks?

Yes. It integrates the Quectel EG25-G module, supporting major global LTE FDD/TDD, WCDMA, and GSM bands. It works in Europe, Asia, North America, Middle East, Africa, etc. Refer to the Quectel EG25-G datasheet for the full band list.

Does this dongle support audio transmission over USB? Can it be used for VoIP or voice calls (e.g., WeChat, Skype)?

No. The hardware does not bring out the PCM (digital audio) lines. Therefore, UAC (USB Audio Class) is not supported, and voice-over-USB is not possible. If you require USB audio support, a hardware customization is necessary – the current standard product size is too small to accommodate the required circuitry.

How can I send SMS messages with this dongle?

You can send SMS using AT commands. Connect the dongle to your computer (USB-A or PH2.0), open a serial terminal (e.g., PuTTY, minicom, or screen), and use the following commands:
  1. AT+CMGF=1 (set text mode)
  2. AT+CMGS="+861234567890" (replace with recipient number)
  3. Enter your message text and press Ctrl+Z to send.
For a full command reference, see the Quectel EG25-G AT Commands Manual.

What physical interfaces are available on this product?

The standard version provides a USB-A male connector (plug-and-play) and a 4‑pin PH2.0 connector. The PH2.0 interface can be used for external power or UART serial communication.

Does the dongle support GPS? How do I get location data?

Yes. It supports GPS/GLONASS/BeiDou via the EG25-G GNSS feature. Enable GPS with AT+QGPS=1, then retrieve location using AT+QGPSLOC=0 (latitude, longitude, altitude, etc.).

Can you customize the dongle to support USB audio (UAC) or PCM digital audio?

Yes, customization is possible, but with constraints:
  1. The current standard PCB size is too small for audio circuitry – a new PCB and enclosure design would be required.
  2. After customization, voice-over-USB via UAC can be supported.
  3. Please contact sales/support for MOQ and NRE (non-recurring engineering) fees.

Is the dongle compatible with Windows, Linux, and macOS?

Yes. The Quectel EG25-G provides standard CDC ECM/RNDIS drivers for networking, plus serial drivers for AT commands and GPS. It works on Windows 7/10/11, most Linux distributions (kernel 4.0+), and macOS (with drivers installed).

Can I use the 4‑pin PH2.0 interface for serial communication?

Yes. The 4‑pin PH2.0 interface provides GND, VCC, UART_TX, and UART_RX. You can connect an external MCU or microcontroller to send AT commands via UART for data connectivity or SMS. Note: This interface does not carry USB data – only UART and power.

Does this product support circuit-switched voice calls?

The EG25-G module itself supports CS voice, but the 4UDEG25G does not bring out analog audio or PCM digital audio lines. Therefore, you cannot connect a microphone or speaker directly. Traditional phone calls are not possible. However, VoIP (voice data over LTE) works as normal data.

Where can I get technical documents and drivers?

Please contact your supplier or visit the Quectel official website to download the EG25-G Hardware Design Guide, AT Commands Manual, and driver packages. We also provide basic user guides upon request.

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