I have the following setup:
- Raspberry Pi 3
- Sixfab 3G/4G Base Shield v2
- Queltec UC20
I have connection to the internet over ppp0 interface but now I want to connect the Instantel Micromate sensor to Raspberry Pi via USB and share that ppp0 to sensor. What I actually want to do is for Raspberry Pi to actually act as a modem (meaning that all traffic from USB will be directly rerouted to ppp0). The problem is that this sensor also recognizes regular USBs and thus Raspberry Pi needs to present itself as a modem. I tried connecting the sensor to Raspberry Pi via USB without SD card in Raspberry Pi and nothing happened of course, apart from RPi turning on and shield lights blinking. However, when I insert SD card into Raspberry and connected the sensor again, it broke the sensor because the sensor thought it needs to install firmware from there or something.
I was Googling a lot on how to make Raspberry Pi a USB modem, but failed to find anything useful. Any help will be appreciated.