No AT response on one linux box, other box works fine. MC7455

This is driving me nuts. I’ve the 1401123-1 development board + USB cable. On two embedded systems I have OpenSuSE 15.0 (leap) installed. Both will show the three /dev/ttyUSB devices appear when I plug in a card (MC7455). But, it is only on one machine that I can get a response from the AT command. It echos the input (via minicom) and does print OK. The other machine the MC7455 completely ignores the AT command (no response).

Other than the software load, both platforms are identical, these are mass-produced systems.

As a side note, of 6 computers & embedded systems, only one is able to communicate with the MC7455 card installed on the dev board. All see /dev/ttyUSB[0-2], but only one gets the OK.

Is there a manual or something that I can read? Website appears to be completely barren of developer info, lots of Sales info though…

Thanks in advance

Hi, You can check driver for Linux and manual here:
Please install driver first then use minicom or picocom to access AT port. Also enable echo by ATE1.

If it answers your question, please help to tick “Solution”.

I don’t see how the drivers would help when trying to communicate with the MC7455 board while it is in the Development board? Two of the systems that I plugged the Dev board into the USB port have the SLQS (Gobi serial & Gobi net) linux kernel drivers installed. The udev does the creation of the /dev/ttyUSB[0-2], but these USB serial devices are unresponsive 115200 baud 8N1 connection from minicom. The ports are unresponsive, no echo, no OK, nothing.

I have a computer that has OpenSuse Leap 15.0 installed on it and the MC7455 modules all work when plugged into the dev board, I get OK etc. from the /dev/ttyUSB0 (115200, 8n1). While I have another computer that is also OpenSuse Leap 15.0 and I get no response at all.

Software updates, packages, probably differ on the two computers, slightly. The two computer systems are identical hardware platforms, really, identical.

Both computers, and both embedded stems have working USB ports. I’ve even copied /lib/firmware contents of the “good” computer over the “bad” computer, still won’t work. A check with fuser does not show any other process using the USB ports. The Suse ModemManger has been removed from those systems. Watching udev behavior with ‘udevadm monitor’ shows expected activity messages for a USB serial device insertion and removal…

Hi, as the two computers are similarly set up so the only thing I can think of now is hardware flow control both on MC7455 and minicom. Could you double check if hardware flow control is the same both on MC7455 and minicom? You can use AT+IFC=0,0 to disable hardware flow control on MC7455 and also disable that on minicom by changing settings of minicom. To enable back hardware flow control on MC7455, try AT+IFC=2,2.