How to connect to BG95 over USB for manual AT commands

IoT Modules LPWA Module
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1

I have created a custom PCB for a BG95 modem in order to connect it to a Raspberry Pi and put it in a gameboy-esque enclosure. See attached photo

IMG20240822115607 (1)
IMG20240822115607 (1)1920×1440 335 KB

The USB port of the Bg95 is soldered directly to one of the raspberry pi USB ports. I am able to boot the BG95 by toggling it’s powering pin using GPIO11 of the raspberry pi. I then see /dev/ttyUSB0 - 2 appear.

When I run

minicom -D /dev/ttyUSB0

or

minicom -D /dev/ttyUSB2

I get a “resource busy” error. I am able to run

minicom -D /dev/ttyUSB1

Which will open up a blank console but when I type AT commands for example ATI and then hit return I see no response.

What minicom settings should I be using? Is there something else going on here? My goal is to be able to send AT commands via my keyboard for debugging purposes.

Thank you

Mark

2

Hi @MonsieurMark

Have you tried to connect USB to PC dirctely and check if could be send AT command?

3

SOLVED.

The solution was that AT commands happen over /dev/ttyUSB2 but by default a Raspberry pi will try to use ModemManager to talk to the BG95 and will therefore consume /dev/ttyUSB2. So, you have to run

sudo systemctl stop ModemManager

and then you can run

minicom -D /dev/ttyUSB2

and then you can send AT commands