Use USB port to connect stm32f4 in EC25

I want to use EC25 usb port to connect stm32f407 usb port,but i can find anything in quectel web site or forum.and i cant find any data about this.please help me and guide me to do this work.

I have another question, please tell me whats the different between “USB MODEM” and “USB AT PORT” and “USB NEMA PORT” and “USB DM PORT”

Thank you in advance.

USB AT PORT is same with the uart at interface but you can access with only USB driver…

USB NEMA port is the gps port of the modem.

USB DM port is the broadcomm QXDM diagnostic log port of the modem.

USB modem is same with the uart at interface but on your computer, you can connect internet with ppp.

I want to use usb port with micro controller,do you know what i have to do?
i want to use usb but i dont know modem usb mode to config micro controller usb mode.

best regards

use uart port instead of the modem usb port for your microcontroller. its be fine for you.
If you want to use with usb. You need to write usb driver for STM32. You can also check stm32f4 usb examples to how your microcontroller communicate over usb.

OK,i am not problem with config my stm32 i need to know what is the EC25 usb class to config my stm32 usb class, and i can pair two device together.

In addition, i pair my modem to mcu with usart but i need to use usb at port.


Dear Samad yarof,
Please refer to the following document to get more information about EC25 USB interface. Hopefully it is useful to you. Thanks!
Quectel_EC21&EC25_USB_Interface_Descriptor_V1.0.pdf (290.8 KB)

hi dear kyson

tank you for your response, I read this pdf,for transfer data from modem to pc is that a protocol or specific packet or specific format?


dear kyson,
I read this pdf and investigate this subjet,i think possibility of this work its 80%,and i need your opinion about this subject.and i need to your help.
i want to connect usb of this module to stm32 microcontroller, in your opinion this work is possible?

I want the USB Interface Descriptor for EC20. Please.


Please just use the above document. Thanks!