@Thomas-Eiszler Hey Thomas
I will save you some time I ran into this issue within the past few months as well. I believe Modal AI is using drivers that predate the SW EM9291. I figured out how to send the commands and submitted the info to them. Hopefully they are able to implement it in an upcoming release. I will attach the same documentation I sent them.
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AT Commands to EM9291 Modem (SDK 1.3.0)
- lsusb (to see device VID/PID)
voxl2:/$ lsusb
Bus 002 Device 003: ID 1199:90e3 Sierra Wireless, Inc.
Bus 002 Device 002: ID 0424:5744 Standard Microsystems Corp.
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 0424:2740 Standard Microsystems Corp.
Bus 001 Device 003: ID 0bda:0811 Realtek Semiconductor Corp.
Bus 001 Device 002: ID 0424:2744 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
- echo VID and PID to this directory
voxl2:/$ echo 1199 90e3 > /sys/bus/usb-serial/drivers/option1/new_id
You can see dmesg output:
[ 72.620475] option 2-1.1:1.3: GSM modem (1-port) converter detected
[ 72.621037] usb 2-1.1: GSM modem (1-port) converter now attached to ttyUSB0
[ 72.621318] option 2-1.1:1.4: GSM modem (1-port) converter detected
[ 72.623288] usb 2-1.1: GSM modem (1-port) converter now attached to ttyUSB1
You can now send AT commands to USB0. I included Sierra Wireless’ qcserial driver in email to Travis that comes from (their?) Mobile Broadband Package for Linux (MBPL). Notice the EM9291 that is defined in there under SDX55 (I think something to do with Snapdragon) has ttyUSB0 as the AT command port, instead of older Sierra modems using ttyUSB2.
I send AT commands like so:
voxl2:/$ echo -ne 'AT!entercnd="A710"\r\n' | busybox microcom -t 1000 /dev/ttyUSB0
Sometimes AT commands returns +CME ERROR if you send commands too fast/don’t wait for reply from earlier command. An example is running AT+COPS=? then running another command before that returns its result. If this happens, I have found this always works to free up that port:
rm -rf /var/locl/LCK…ttyUSB0
You can read more about this solution here:
https://forum.sierrawireless.com/t/em9191-does-not-bring-up-the-serial-interface-works-in-mbim-only-usb-composition/24783/3