Issue to send at commands using echo-e at command not respond but using same serial at minicom its worked

Installing and Using OpenWrt
1

i have router in which one usb port is there where i am using huawei e3276 modem .
i am using ncm protocol on dongle and through kmod -usb-serial-option package it gives two serial port /ttyUSB0 and ttyUSB1 and i send at command using minicom ttyusb0 it work fine and respond properly.
but i am using echo -e "AT \r\n" > /dev/ttyUSB0 && cat /dev/ttyUSB0 it is not respond .
please help me if any idea why it is happened

3

Be aware that busybox echo(1) does not support GNU extensions (such as the -e parameter), but implements only the bare minimum subset as defined for a POSIX/ SUSv4 compliant echo(1) implementation.

For portability and interoperability reasons you should prefer to use printf(1), instead of echo(1).

4

Thank for reply.....
echo is worked actually i tested it write to serial port using echo -e "AT \n" >/dev/ttyUSB0 on one terminal and on another terminal i read it cat < /dev/ttyUSB0 so it read successfully AT .but my issue is AT command not respond or not ok coming .but using minicom it respond please help me

5

You won't see the replies using that method.

The actual output is on the physical serial Tx/Rx pins.