Where the openwrt runs on EHS6T | Thales IoT Developer Community

Hi!

Communication between a Java program on the modem and the OpenWRT Linux can be done through an internal USB port.
An easy test is to set AT^SCFG="Userware/Stdout","usb1" on the modem side and read it by cat < /dev/ttyACM1 on the OpenWRT side. 
Loading, installing and starting e.g. HelloWorld will show the output on the /dev/ttyACM1 on the OpenWRT side.

Here is some USB  port information I found so far, by trial and error:

USB1 - /dev/ttyACM1 can be used both ways to communicate between the modem and OpenWRT
USB2 - /dev/ttyACM2 can be used both ways to communicate between the modem and OpenWRT
USB3 - /dev/ttyACM3 telnet port to modem AT command interface ("telnet localhost 1234")
USB4 - /dev/ttyACM4 3G modem communications (gateway usage)
USB5 - /dev/ttyACM5 smsd if used (creates a large log, disable: /etc/init.d/smstools3 disable
USB6 - /dev/ttyACM6 can be used both ways to communicate between the modem and OpenWRT

- USB1 and USB2  are reserved for tracing by Gemalto M2M GmbH (on device debugging) so be
  careful during development phase

There are many ways to write a script on the OpenWRT side to read a port and store the results. like:
while :; do read X < /dev/ttyACM1; echo $X > /tmp/all_information; done &
You can also write a script with a while loop and monitor a command like reboot.
When thie string comes, the script reboots the OpenWRT side.

Best regards,
Antero

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