Hello, I have just upgraded my Mango Router MT-300N-V2 to firmware 3.216.
I am using a 3G USB modem (Huawei E122) to connect to the internet using a mobile operator SIM card with a data-plan.
The Huawei E122 needs a specific sequence of AT commands to connect to the mobile operator, that I provided modifying the vi /etc/chatscripts/3g.chat file.
It looks like the following:
root@GL-MT300N-V2:~# cat /etc/chatscripts/3g.chat
ABORT BUSY
ABORT ‘NO CARRIER’
ABORT ERROR
REPORT CONNECT
TIMEOUT 10
“” “ATE0”
OK “ATZ E0 V1”
OK “AT+CFUN=1”
OK ‘AT+CSCS=“UCS2”’
OK “AT+CREG=2”
OK “AT+CGREG=2”
OK “AT+COPS=3,2;+COPS?”
OK ‘AT+CGDCONT=1,“IP”,“$USE_APN”’
SAY “Calling UMTS/GPRS”
TIMEOUT 30
OK “ATD$DIALNUMBER”
CONNECT ’ ’
Previous firmware revisions of the Mango router always worked fine with this configuration. The USB modem was autodetected and connected properly via /dev/ttyUSB0. The USB modem registered to the network and used the provided APN to get internet connectivity.
Wed Apr 26 05:54:02 2023 daemon.info pppd[26158]: Renamed interface ppp0 to 3g-modem_1_1
Wed Apr 26 05:54:02 2023 daemon.info pppd[26158]: Using interface 3g-modem_1_1
Wed Apr 26 05:54:02 2023 daemon.notice pppd[26158]: Connect: 3g-modem_1_1 ↔ /dev/ttyUSB0
The new firmware 3.216 seems to have introduced a glitch.
The USB modem does not register to the network (no blue LED blinking on it) like if the 3g.chat file does not get executed when the pppd gets started.
I have found a workaround, but it does not look very clean.
I am forcing the AT commands of the 3g.chat file using the rc.local file that gets automatically executed after the Linux Kernel start-up.
I have added those lines to pass the required AT commands. I have also found that a network reload on OpenWRT is needed to get the modem_1_1 interface wan to force ppp0 to retry and restart the modem_1_1 interface.
root@GL-MT300N-V2:~# cat /etc/rc.local
echo -e “ATE0” > /dev/ttyUSB0
echo -e “ATZ E0 V1” > /dev/ttyUSB0
echo -e “AT+CFUN=1” > /dev/ttyUSB0
echo -e “AT+CSCS=“UCS2"”> /dev/ttyUSB0
echo -e “AT+CREG=2” > /dev/ttyUSB0
echo -e “AT+CGREG=2”> /dev/ttyUSB0
echo -e “AT+COPS=3,2;+COPS?” > /dev/ttyUSB0
echo -e “AT+CGDCONT=1,“IP”,”$USE_APN”" > /dev/ttyUSB0
sleep 50
/etc/init.d/network restart
Have you any idea why the 3g.chat AT commands script does not get executed properly when ppp0 starts in the current most actual firmware (3.216)?