Hi,
I am trying to use the Quectel EG25-G to connect to AWS IoT w/MQTT using Python on a Raspberry Pi 4.
The setup appears to be correct. I can ping over the LTE network with ‘ping -I usb0 www.google.com -c 5’ successfully. I can also use Minicom to send AT commands to the Quectel modem and get responses. I believe the HW is setup correctly.
But I am stuck with trying to send commands and manage the EG25-G in Python. I have determined there are 5 interfaces on the EG25-G and that all are attached to the kernel. I have Python code that successfully detaches the five interfaces from the kernel and they should now be available for my Python code to use.
How do I write AT commands to the EG25-5 using the USB interfaces? I have read the Quectel USB Interface Descriptor and MQTT Application Note documentation but still confused on what to actually do.
I guess I am having trouble understanding how to send the Quectel LTE module AT commands from Python using USB. Anyone able to share guidance on what I am doing wrong? Or even if I am on the wrong path completely 
Thanks so much for any help.
