Can't configure 4G modem anymore

Q&A forumCategory: QuestionsCan't configure 4G modem anymore
pigosso asked 3 months ago

I went to check if I could find some connection log (RTK inexplicably disappears sometimes), but I can’t connect to the 4G modem anymore.
I cannot get any kind of reply from the thing, and I have tried everything, including resetting the config and re-uploading it (the board is still surely operating though, since the red led blinks fast).
The serial port driver is the normal one by FDTI.
I also set UART2 to none/none, and toggled to it the relative physical switch (GPS>XBEE is not blinking).

Ardusimple Staff replied 3 months ago

Hi pigosso,
1. In the Telit AT Controller, in the port settings, is flow control disabled?
2. Did you try without SIM card?

If you still don’t succeed, it would be great if you could make a video of how you try to configure it send it to

pigosso replied 3 months ago

Flow control is disabled and the SIM didn’t seem to make much difference (I mean, besides the led starting to blink fast instead of slow).

I have also tried with different cables, including having two connected at the same time.

My suspect is that some setting (which doesn’t get reset with the normal “revert to default” procedure) is incorrect, or perhaps some weirdness with baudrate in either Windows or Telit AT.

Ardusimple Staff replied 3 months ago

Hi pigosso,

I suggest we transfer your case to, if you could record a video while:
1. Confirming the position of the switch under the XBee socket.
2. Confirming that zed-f9p uart-connected-to-the-xbee, has protocol out and protocol in = NONE.
3. Showing Telit AT Controller configuration
4. Showing how you press XBEE reset 3-4 seconds before pressing PLAY button on the Telit AT Controller.

pigosso replied 3 months ago

I sent you the video tonight.

Ardusimple Staff replied 3 months ago

received and commented. will continue investigation via email.

1 Answers
pigosso answered 3 weeks ago

Just for the records, it turned out my 4G module had somehow gone bugged out of the blue (AT commands could be sent to it correctly, at least good enough the blinking led could be controlled, but no kind of reply could ever come back).
The AS guys checked it and then shipped me back a working one. I couldn’t be happier now.
The only other difficulty I had, was just remembering that a standalone simpleRTK2B with internet-provided corrections has to be set with the Rover config, rather than Base.

Ardusimple Staff replied 3 weeks ago

Thanks for sharing!